antimicrob mch phagocytes bact evasion.09

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Professioa phagocytes, sch as macrophages, e-trophis ad dedritic ces, are iqey qaified toegf arge ( 0.5 m) partices, icdig microorga-isms. The iteraizatio ad sbseqet destrctioof pathoges are key to the iate imme respose,ad promote atige presetatio ad the deeop-met of adaptie immity. After egfmet, themicroorgaisms are trapped, together ith extrace-ar fid, i a acoe, or phagosome, deried from thepasma membrae. Becase the ascet phagosomamembrae ad its cotets are iocos, they mstdergo a drastic coersio to acqire the microbi-cida ad degradatie featres associated ith iateimmity. This coersio, ko as phagosomamatratio, is accompished throgh a stricty cho-reographed seqece of fsio ad fissio eets thatioe defied compartmets of the endocytic pathway

(FIG. 1). Effectie phagocytosis therefore reqires tocompoets: partice iteraizatio ad phagosomamatratio.

Athogh most bacteria are sccessfy itera-ized ad eimiated by phagocytes, seera patho-ges hae deeoped sria strategies that iterfereith the iteraizatio ad/or matratio processes.Preetio ad maagemet of the ifectios casedby sch pathoges od obiosy beefit fromderstadig the maer i hich they circm-

et ad ofte co-opt the imme respose. This, itr, reqires detaied koedge of the basic mecha-isms deryig phagocytosis. To this ed, e brief y

smmarize or crret koedge of phagocytosis addescribe saiet exampes of bacteria species that haeeoed distict strategies to eade kiig.

Phagosome formation

The iteractio of the microorgaism ith the phago-cyte ca be direct, throgh recogitio of pathoge-associated moeces (sch as srface carbohydrates,peptidogycas or ipoproteis) by patter recogitioreceptors, or idirect, throgh mediatio by opsois.Opsois are host factors, sch as immogobi G(IgG), ad compoets of the compemet cascade thatattach to the pathoge srface, acqirig a coforma-tio that is recogized by phagocytic receptors, schas Fc receptors (FcRs) ad compemet receptor 3(CR3)1. The sigaig that is triggered by the partice

aries depedig o the atre of the receptors egaged.

The pathay eicited by FcR is best derstood.Exposre to mtiaet igads idces csterig ofthese receptors i the pae of the membrae, iitiatigphosphoryatio of their cytopasmic immoreceptortyrosie-based actiatio motifs (ITAMs) by Src-famiykiases2. ITAM phosphoryatio recrits ad actiatesthe tyrosie kiase SYK, hich i tr phosphoryates

arios sbstrates3. The eets that foo SYK actia-tio ad cmiate i partice egfmet are ot asceary derstood. Remodeig of acti is ambig-osy reqired for psedopod extesio ad, i thecase of FcR, poymerizatio is drie by Rac1 ad/or Rac2, ad ce diisio cotro protei 42 (Cdc42)4.

Program in Cell Biology,

The Hospital for Sick Children,

555 University Avenue,

Toronto, Ontario M5G 1X8,

Canada.

Correspondence to S.G.

e-mail: [email protected]

*These authors contributed

equally to this work.

doi:10.1038/nrmicro2128

Endocytic pathway

The route followed inside the

cell by vesicles derived from

the plasma membraneby

endocytosis, including theirmembrane-associated cargo

and trapped fluid. Vesicles or

vacuoles derived from the

plasma membrane undergo

fusion and fission events that

deliver some of their

components to lysosomes for

degradation, whereas others

are recycled.

Antimicrobial mechanisms ofphagocytes and bacterial evasionstrategiesRonald S. Flannagan*, Gabriela Coso* and Sergio Grinstein

Abstract | Professional phagocytes have a vast and sophisticated arsenal of microbicidal

features. They are capable of ingesting and destroying invading organisms, and can present

microbial antigens on their surface, eliciting acquired immune responses. To survive thishostile response, certain bacterial species have developed evasive strategies that often

involve the secretion of effectors to co-opt the cellular machinery of the host. In this Review,

we present an overview of the antimicrobial defences of the host cell, with emphasis on

macrophages, for which phagocytosis has been studied most extensively. In addition, using

Mycobacterium tuberculosis, Listeria monocytogenes, Legionella pneumophila andCoxiella

burnetii as examples, we describe some of the evasive strategies used by bacteria.

R E V I E W S

nATuRE REvIEwS |Microbiology vOuME 7 | MAY 2009 |355

f o c uS o n mI c R o bI a l h o S t c E ll S ubV E R S I o n

2009 Macmillan Publishers Limited. All rights reserved
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CD63

HOPS Rab5

ESCRT Cathepsins

Cathepsins

Rab7

Hydrolases

HydrolasesLAMP1

LAMP2

RILP

MicrotubulesDynein ordynactin

VPS34PI(3)P

Rab5

RABEX

Multivesicular body Late endosomeEarly endosome Lysosome

EEA1

V-ATPase

a Early

pH 4.5

b Intermediate c Late

PI(3)P

Trans-Golgi networkMHC II

presentationRecycling endosome

BacteriumBacterium

Bacterium

d Phagolysosome

LBPALBPA

LAMP1

LAMP2

7.4

Bacterium

Phosphoinositide

An inositol phospholipid that

can be phosphorylated

separately or at all possible

combinations of the D-3, D-4

and D-5 positions of theinositol ring.

SNARE protein

A member of the soluble

N-ethylmaleimide sensitive

factor attachment protein

receptor family that mediates

docking and fusion of cellular

membranes. Cognate SNARE

pairs on the vesicular and

target membranes intertwine

to form a SNARE pin that

brings the membranes into

close apposition, driving their

fusion.

The idetity of the gaie ceotide exchage fac-tors (GEFs) that are resposibe for Rac ad Cdc42actiatio are the sbject of debate5,6. By cotrast, it isgeeray agreed that dostream effectors, sch aswiskottAdrich sydrome protei7, hich i triteracts ith ad actiates acti-reated protei 2/3(Arp2/3), are actiey ioed i acti poymerizatiodrig FcR-iitiated phagocytosis8. I the case of CR3-mediated phagocytosis, the diaphaos-reated formiDia1 (aso ko as DIAPH1) is thoght to iitiateacti fiamet ceatio ad eogatio4,9.

Phosphoinositides aso proide a importat cotri-btio to acti remodeig drig phagocytosis. Bothphosphatidyiosito-4,5-bisphosphate ad phosphati-dyiosito-3,4,5-trisphosphate accmate at sites ofpartice egagemet ad are istrmeta i timigthe oset ad termiatio of acti assemby. whereas

phosphatidyiosito-4,5-bisphosphate is essetiafor the iitia poymerizatio that dries psedopodformatio, its coersio to phosphatidyiosito-3,4,5-trisphosphate seems to be reqired for psedo-pod extesio ad phagosoma cosre10, at east ipart by recritmet of myosi X11. The metaboismof other phosphoipids by phosphoipases A ad D isaso ecessary for sccessf competio of phagocyto-sis12,13, athogh the precise prodcts ad mechaismsioed hae ot bee fy resoed.

Drig phagocytosis of arge or mtipe partices,a cosiderabe amot of membrae is iteraized,ad the ce eeds to compesate for the oss of srface

area. Paradoxicay, capacitace measremets haesho that the pasmaemma srface i fact icreasesdrig phagocytosis14. This has bee attribted to focaexocytosis of edomembraes at sites of phagocyto-sis. Recycig15 ad ate edosomes16 are thoght to bethe mai cotribtors, bt ee ysosomes hae beereported to fse he the demad for membrae isexcessie17,18. Rab ad ADP-ribosyatio factor (Arf)GTPases are thoght to be importat i directigad tetherig the edomembrae orgaees to formphagosomes19,20, hereas SNARE proteins (sobe nSF-attachmet protei receptor proteis), icdig esice-associated membrae protei 3 (vAMP3)15 ad vAMP7(REF. 16) derpi the fsio reactio.

Phagosome maturation

Matratio starts immediatey after, ad possiby ee

before, phagosome seaig. After scissio from the sr-face membrae, the phagosome dergoes seqetiafsio ith eary edosomes, ate edosomes ad yso-somes21. whether compete fsio of the icomig mem-braes ith the pre-existig acoe or kiss ad reets are ioed remais cear ad a combiatioof both may occr. Regardess, remodeig of the mem-brae of the phagosome is accompaied by acte chagesi the compositio of its me, hich becomes a highyacidic, oxidatie ad degradatie miie. The steps ead-ig to the formatio of the phagoysosome, hich is thetermia stage of the matratio seqece, are istratedi FIG. 1 ad discssed i more detai beo.

Figure 1 | Staes pasma matuat. Shortly after pathogen uptake, the phagosomeundergoes a seriesof

transformations that result from its sequential interaction with subcompartments of the endocytic pathway. Different

stages of maturation are recognized early (a), intermediate () and late () phagosomes that culminate with the

formation of phagolysosomes (). During maturation, the phagosomes acquire various hydrolases and undergo a

progressive acidification caused by proton pumping by the V-ATPase. EEA1, early endosome antigen 1; ESCRT,

endosomal-sorting complex required for transport; HOPS, homotypic protein sorting; LAMP, lysosomal-associated

membrane protein; LBPA, lysobisphosphatidic acid; PI(3)P, phosphatidylinositol-3-phosphate; MHCII, major

histocompatibility complex II; RILP, Rab-interacting lysosomal protein.

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Multivesicular body

(MVB). A defined stage in

the transit between early

endosomes and late endosomes

or lysosomes. MVBs are

characterized by a limiting

membrane that encloses

internal vesicles rich in lyso-

bisphosphatidic acid, CD63

and phosphatidylinositol-

3-phosphate. Proteins destined

for degradation are sorted to

internal vesicles of MVBs.

The early phagosome. ney formed phagosomes rap-idy gai may of the properties of eary edosomes.They hae a propesity to fse ith sortig ad recy-cig edosomes ad are refractory to fsio ith yso-somes22,23. Their me is midy acidic (pH 6.16.5)ad poor i hydroytic actiity24.

The sma GTPaseRab5A itegrates the targetig, teth-erig ad fsio of eary edosomes25, ad aso seems tobe ioed i the dyamics of eary phagosomes, i hichit is actiated by the GAPvD1 (GTPase-actiatig proteiad vPS9 domai-cotaiig protei 1) exchage factorafter the igestio of apoptotic ces26. Rab5A acts sigmtipe effectors, icdig the p150hvPS34 compex,eary edosome atige 1 (EEA1) ad SnARE proteis.The Ser ad Thr kiase p150 spports the recritmetof hvPS34, a cass III phosphatidyiosito-3-kiase thatgeerates phosphatidyiosito-3-phosphate (PI(3)P) othe eary phagosoma membrae27. PI(3)P achors effec-tor proteis, sch as EEA1, to the cytosoic face of thephagosome throgh FYvE ad PX domais28,29. EEA1,hich aso iteracts directy ith Rab5 (REF. 30), is thoght

to act as a bridge that tethers eary edosomes to icomigedocytic esices31, ad probaby has a eqiaet roe iphagosomes. Additioay, EEA1 iteracts ith sytaxi 13(REF. 32), a SnARE protei reqired for membrae fsio,ad ith a N-ethymaeimide-sesitie fsio proteithat is essetia for the disassemby ad rese of SnAREcompexes33.

Despite repeated rods of fsio ith edomem-brae esices, the srface area of the phagosomamembrae does ot icrease perceptiby, ad coti-es to eeop the iteraized partice tighty. Thisprobaby rests from the cocomitat occrrece ofmembrae fissio eets. Simiary to eary edosomes,phagosomes are thoght to be abe to recyce moecesto the pasma membrae by a process ioig coatprotei I (COPI), ad Arf ad Rab GTPases34. Rab11A,hich as preiosy ko to mediate recycig ofedosomes to the pasma membrae, aso participatesi the retriea of phagosoma costitets to the pas-maemma35, a process that is regated by the Rab-copig protei36,37. I additio, cargo is retrieed toedosomes ad the trans-Gogi etork by a compexof carrier esices, tbes ad moecar motors38. Theretromer compex of sortig exi 1 (SnX1), SnX2,

acoar protei sortig-associated protei 26A(vPS26A),vPS29 ad vPS35, hich iks cargo seec-tio to tbe geeratio i edosomes, is ikey to pay

a simiar part i phagosomes. SnX4 ad EH domai-cotaiig protei 1 (EHD1), to other compoetsthat are actie i retriea ad tbe stabiizatio iother systems39,40, may aso cotribte to phagosomamatratio.

I additio to bddig otards for the prposeof retriea, phagosomes diert membrae-associatedcargo that is destied for degradatio to itramia

esices. Sch esices are thoght to arise from iardsbddig ad pichig of the imitig membrae ofthe phagosome, i a maer aki to the geeratioofmultivesicular bodies (MvBs). This iitiay occrsat a stage e desigated as itermediate i FIG. 1, as it

possesses featres that are ot preset i eary phago-somes, bt acks other featres that are typica of atephagosomes (discssed beo). As i edosomes, phago-soma membrae proteis destied for degradatio arebiqitiated ad associate ith the edosoma-sortigcompex reqired for trasport (ESCRT)41. I MvBs, thefia compoet of the compex, ESCRTIII, forms a at-tice that i cojctio ith the ATPase vPS4A forcesthe extrsio of esices ito the orgaear me42,43.Phosphatidyiosito-(3,5)-bisphosphate sythesized bythe FYvE figer-cotaiig phosphoiositide kiasePIP5K3 (PIKfye kiase) may aso be importat for

esicatio, as it bids to ESCRTIII44.

The late phagosome. Oce the recycig proteis areremoed, the phagosome proceeds to the ate stage,hich is characterized by a more acidic mia pH(5.56.0) broght abot by the acqisitio of additioaproto-pmpig v-ATPases21. The ate phagosome isaso eriched i proteases ad ysosoma-associatedmembrae proteis (AMPs), hich are either imported

from the Gogi compex or acqired by fsio ith ateedosomes. itte is ko abot ate phagosome dyam-ics21. The sma GTPase Rab7Ais a characteristic marker ofthis orgaee, ad is ko to mediate the traffic beteephagosomes ad ate edosomes or ysosomes45,46. ThevpsChomotypic protei sortig (HOPS) compex, hichmediates the trasitio from Rab5A- to Rab7A-positieedosomes47, probaby seres a simiar fctio i phago-some matratio. Hoeer, hereas vpsCHOPS doesregate esicar traffic ad fsio drig ysosomebiogeesis, it is ot eeded for Rab7A recritmet48,49.Regardess of ho it is acqired, Rab7A recrits seeraeffectors to the acoar membrae. Oe sch effector,Rab-iteractig ysosoma protei (RIP), promotes thecetripeta moemet of ate phagosomes ad ysosomesby bridgig the membrae to the dyeidyactimotor compex process46,50. Fsio of edosomes adysosomes is faciitated by brigig the orgaeesi cose appositio so that SnAREs sch as vAMP7advAMP8ca compete membrae coaescece51,52, adphysica proximity is eqay ikey to faor fsio ofphagosomes. Athogh ecessary, Rab7A ad RIP areot the oy mediators of ate phagosome matratio.Phosphatidyiosito-3-kiase atagoists bock phago-some matratio despite the acqisitio of Rab7A adRIP53, impyig that a separate, iositide-depedeteet is aso essetia.

Retriea ad disposa of membrae compoetsaso occr at this stage. Simiary to ate edosomes, atephagosomes cotai ysobisphosphatidic acid (BPA),a iqe ipid fod i mia esices of MvBs.Programmed ce death 6-iteractig protei (PDCD6IP;aso ko as AIX), hich bids BPA ad ca ikESCRTI ad ESCRTIII54 i edosomes, is specated toparticipate i the iard bddig process.

Phagolysosome. The matratio process cmiates iththe formatio of the phagoysosome, the timate micro-bicida orgaee. Phagoysosomes are edoed ith acompete, sophisticated armametarim to eimiate ad

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Cytoplasm

PhagosomepH ~4.05.0

Bacterium

p47

p67

V-ATPase

Antimicrobialpeptides

SOD

iNOS

Citruline Arginine

NO ONOO NO2

HOCl

MPO

Defensins

Metal transporters Proteases

+ + + + + +

Stress proteasesand proteasome

Lys

Lys + H+

CadAROS

IntactDNAandprotein

OxidizedanddamagedDNA andprotein

Cadaverine

iNOS

Citruline Arginine

O2

p40

Fe2+

Fe2+

H+

H+

NADP+ + O2

ADPH

Cytochrome b558

NADPH oxidase

H2O2

2 H2O2

HO

Lactoferrin

NADPH oxidase

2 H2O + O2

ProteasesAra4N

Catalase

Host microbicidal factors b Microbial defensive mechanisms

degrade microorgaisms (discssed beo). They aregeerated by fsio ith ysosomes throgh a Rab7A-depedet process ad are highy acidic (mia pH

aes as o as 4.5 hae bee reported). Isertio of addi-tioa v-ATPases ad tighteig of the H+ eak accotfor the accetated acidificatio. Phagoysosomes cabe differetiated from ate phagosomes by their pacityof BPA or PI(3)P-eriched itera membraes55,56, bytheir eeated matre cathepsi cotet ad by their ackof maose-6-phosphate receptors57.

Microbicidal activity of the phagosome

Drig the corse of matratio, phagosomes acqirea f arsea of atimicrobia featres (FIG. 2), hich aredescribed idiiday beo.

Acidification of the phagosome.The v-ATPases thatacidify the phagosoma me cosist of a cytopas-mic v

1compex that hydroyses ATP ad trasfers the

eergy to a membrae-embedded v0

compex thattrasocates H+ across the biayer58. Phagosoma acid-

ificatio creates a hostie eiromet that impedesmicrobia groth59: ot oy does it directy impairthe metaboism of some bacteria, bt it aso faors

the actiity of may hydroytic ezymes of the phago-cyte that hae acidic pH optima. I additio, the tras-membrae H+ gradiet geerated by the v-ATPase issed to extrde essetia microbia triets from thephagosoma me. The v-ATPase aso faciitates thegeeratio of speroxide (O

2) by trasportig H+

i a accompaied (ad therefore eectrogeic)maer, thereby coteractig the egatie chargestrasocated by the nADPH oxidase. The prodcts ofthe oxidase ca sbseqety combie ith H+ i theme of the phagosome, geeratig more-compexreactie oxyge species (ROS) (discssed beo).

Phagosoma acidificatio is ot oy a coseqeceof phagoysosome formatio, bt seems to be a ite-gra eemet of the matratio process, as it directycotros membrae traffic60,61. Dissipatio of the pHgradiet across the phagosoma membrae by addi-tio of eak bases or by iterferece ith v-ATPaseactiity arrests matratio, preetig the formatioof phagoysosomes. Eidece deried from the edo-cytic pathay sggests that acidificatio is reqired

for the assemby of COPI compexes62 ad for therecritmet ofARF6 ad cytohesi 2 (aso ko asARnO) (REF. 63).

Figure 2 | Te ma asea pates esus te eese measms te masm. The

host microbicidal mechanisms (a) include the NOX2 (also known as CYBB) NADPH oxidase, the inducible NO synthase

(iNOS), iron scavengers and exporters, such as lactoferrin and natural resistance-associated macrophage protein 1

(NRAMP1; also known as SLC11A1), plus antimicrobial peptides and proteins that permeabilize and degrade the bacteria.

Bacterial defensive mechanisms () include modification of their surface to resist or break down antimicrobial peptides,

and expression of enzymes, such as catalase, that convert reactive species to less harmful compounds or prevent

recruitment of the protein complexes that synthesize reactive nitrogen species (RNS) or reactive oxygen species (ROS)

(see the main text for details). SOD, superoxide dismutase.

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Azurophil or primary

granule

A specialized neutrophil

granule, also called a peroxi-

dase-positive granule, that

resembles lysosomes, in that it

contains degradative enzymes,

such as -glucuronidase,

cathepsins, elastase, lysozyme

and myeloperoxidase, as well as

antimicrobial peptides, such

as defensins.

Specific or secondary

granule

A specialized neutrophil

granule, also called a peroxi-

dase-negative granule, that

exists as a heterogeneous

continuum of granules with

varying amounts of lactoferrin,

collagenase, heparanase,

lysozyme and antimicrobial

cathelicidins.

Reactive oxygen and nitrogen species.Professioaphagocytes destroy pathoges i part throgh ROSgeerated directy or idirecty by the nOX2 (asoko as CYBB or gp91phox) nADPH oxidase.Becase ROS prodctio is most promiet i e-trophis, most of or koedge of nOX2 bioogy isderied from this ce type. The importace of ROSi pathoge eimiatio is highighted by idiid-as ith mtatios that case partia or tota iac-tiatio of the oxidase64. These patiets sffer fromchroic graomatos disease, hich is character-ized by seere recrret ifectios that ca rest ideath65. nOX2 is a mtisbit compex, cosistigof a trasmembrae heterodimer (CYBB ad CYBA)that after actiatio assembes ith three cytosoicsbits (etrophi cytoso factor 4 (nCF4), nCF1ad nCF2)64.Rac1 adRac2 are aso reqired for acti-

atio of the ezyme66,67. The actie oxidase trasferseectros from cytosoic nADPH to moecar oxyge,reeasig O

2 ito the phagosoma me68. withi

the phagosome, O2

ca dismtate to H2O

2, hich ca

i tr react ith O2 to geerate hydroxy radicasad siget oxyge69. H

2O

2ca aso be coerted by

myeoperoxidase ito hypochoros acid ad chor-amies70. Coectiey, these highy reactie, toxic ROSeffectiey ki itraphagosoma microorgaisms. ThenOX2 nADPH oxidase has aso bee ioked i theactiatio of proteoytic ezymes by idirecty aterigthe ioic compositio of phagosomes71,72, bt this roeremais cotroersia73.

Simiary to ROS, itric oxide (nO) ad thereactie itroge species (RnS) deried from it areimportat atimicrobia effectors. RnS are promi-et i macrophages, i hich they hae bee stdiedi greatest detai. The actiity of the idcibe itricoxide sythase, or nOS2, the isoform most reeat tophagocytes74, is regated at the trascriptioa ee;RnS prodctio reqires de novo sythesis of the pro-tei i respose to proifammatory agoists74. Thesythase fctios as a dimer: oe sbit trasferseectros from nADPH to FAD, the to FMn (faimooceotide) ad to the haem iro of the adja-cet sbit, to prodce nO ad citrie froml-argiie ad oxyge75. uike speroxide, nO issythesized o the cytopasmic side of phagosomes,bt has the abiity to diffse across membraes toreach itraphagosoma targets76. I the mia ei-romet, here it ecoters ROS, nO ca dergo

either spotaeos or cataytic coersio to a rageof RnS, icdig itroge dioxide (nO

2), peroxyi-

trite (OnOO), diitroge trioxide (n2O

3), diitrosy

iro compexes, itrosothios ad itroxy (HnO)74.ROS ad RnS syergize to exert highy toxic effectso itraphagosoma microorgaisms. They iteractith meros microbia targets, sch as thios, metacetres, protei tyrosie resides, ceic acids adipids77. As a rest, proteis are iactiated ad ipidsare coerted by oxidatie damage. I additio, micro-bia DnA ca dergo irreparabe damage. Together,these reactios ca impair bacteria metaboism adtimatey ihibit repicatio.

Antimicrobial proteins and peptides. A set of proteisthat atagoize bacteria groth compemet the phago-soma ietory of atimicrobia toos (TABLE 1). Theyca be grossy sbdiided ito those that preet grothad those that compromise the itegrity of the micro-orgaism. Groth preetio ca be accompished byimitig the aaiabiity of essetia triets iside thephagosome. To this ed, phagocytes secrete scaegersito the me or isert trasporters ito the phago-soma membrae. This has bee iestigated i moredetai i etrophis, hich are eqipped ith specia-ized graes (azurophil or primary granules, specific orsecondary granules ad geatiase graes) ad secre-tory esices that he stimated reease their co-tets extraceary ad/or ito the phagosome78. Oesch scaeger is actoferri, a gycoprotei cotaiedi etrophi graes that is reeased ito the phago-some me, here it seqesters iro that is reqiredby some bacteria79. The other strategy is istrated byatra resistace-associated macrophage protei 1(nRAMP1; aso ko as SC11A1), a itegra mem-

brae protei expressed i ate edosomes ad ysosomesthat is recrited to the phagosoma membrae soo afterpathoge ptake. nRAMP1 exerts a bacteriostatic effectby extrdig diaet catios, sch as Fe 2+, Z2+ adM2+ from the phagosoma me80. Fe2+ ad Z2+ arecofactors of microbia hosekeepig ezymes, ad M2+is reqired by speroxide dismtase, a key protectieezyme expressed by certai pathoges.

More-direct mechaisms depoyed by phagosomes todisrpt the itegrity of pathoges ioe the defesis,catheicidis, ysozymes, ad assorted ipases ad pro-teases (TABLE 1). The defesis, hich are sbdiidedito ad sbgrops, are sma, disphide-bridgedpoypeptides of 10 kDa that i etrophis are storedithi azrophi or primary graes81. Defesis bidto egatiey charged moeces o the microbia srface.They sbseqety idce membrae permeabiizatioof Gram-positie ad Gram-egatie bacteria by form-ig mtimeric io-permeabe chaes81. Catheicidisare aso sma proteis of 10 kDa that etrophis storeas proforms i secodary graes82. The precrsors arecoerted to actie species by eastase, a primary gra-e protei they probaby ecoter i the phagosomame. Catheicidis act by permeabiizig the cea ad ier membrae of Gram-positie bacteriaad the oter ad ier membraes of Gram-egatiebacteria82.

Phagosomes are aso eqipped ith a assortmetof edopeptidases, exopeptidases ad hydroases thatdegrade arios microbia compoets. The edopepti-dases are made p of cysteie ad aspartate proteases,hereas the exopeptidase poo cosists of cysteie adserie proteases83. Edopeptidases, particary theC1 famiy of cysteie proteases, are especiay impor-tat, becase they efficiety geerate sbstrates for theexopeptidases83. not a the proteases are acqired sim-taeosy by the matrig phagosome, impyig that theyare deiered by distict orgaees. Cathepsi H is pre-domiat i eary phagosomes, hereas cathepsi S istypicay preset i ate phagosomes84.

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Hydroases that target carbohydrates (for exampe,-hexosamiidase, -gcroidase ad ysozyme) adipids (for exampe, phosphoipase A2) are aso deieredto the phagosomes.

Bacterial resistance to phagocyte killing

Despite the presece of these atimicrobia host factors,may pathoges ca srie iside the host ce. Schpathoges, hich icde bacteria, fgi ad irses,hae eoed a mtitde of strategies to coteracthost defeces. For simpicity, e cofie the remai-der of this Reie to bacteria pathoges. Some bac-teria species iterfere ith the abiity of phagocytesto egf them85,86, either by scaegig, ihibitig oree degradig opsoic atibodies or compemet8789,or by directy impairig the phagocytic machiery ofmacrophages ad etrophis85,86,90. Other bacteria hae

become resistat to oe or more of the atimicrobia fac-tors of phagocytes (FIG. 2). Some species hae deeopedmetaboic pathays to coteract acid accmatioiside phagosomes or hae acqired iqey resistatproteis to ithstad the o pH91,92. Yet other bacteriaprotect themsees by actiey degradig93 or shiedigthemsees94,95 from the atimicrobia peptides ad pro-teis prodced by phagocytes, or by expressig detoxi-fyig ezymes, sch as cataase, that etraize ROSad/or RnS96,97. Ateratiey, some bacteria speciespreet RnS ad ROS formatio by impairig recrit-met of the proteis that mediate their sythesis98,99.Other species hae deised meas of oercomig the

scarcity of iro by secretig speciaized iro-scaegigmoeces caed siderophores, hich seqester adtarget the catio for bacteria se100, or by expressigiro storage101 or trasport proteis102. asty, maybacteria improe their itraphagosoma sria bymotig a igoros stress respose to dispose of adrepace damaged proteis103.

Athogh most bacteria se oe or more of theseresistace mechaisms, oy a seect grop of bacteriaare professioa itracear pathoges. These speciessrie ad repicate iside phagocytes, effectiey aoid-ig attack by their atimicrobia factors. To accompishthis feat, sch pathoges hae eoed mtipe strate-gies toards oe commo goa: to pertrb phagosomamatratio. These differet strategies are exempifiedby the mechaisms sed byMycobacterium tuberculo-sis, Listeria monocytogenes,Legionella pneumophila adCoxiella burnetii. These bacteria parasitize host ces byarrestig or reprogrammig phagosoma matratio,by escapig matrig phagosomes or by ithstadigthe microbicida properties of the phagoysosome.

M. tuberculosis: inhibition of phagosomal maturation.The pathogeicity ofM. tuberculosis is argey attribtedto its abiity to srie ithi macrophages by arrestigphagosoma matratio104. This bacterim is exqisiteyadapted to ife ithi macrophages ad ot oy arrestsphagoysosome formatio bt ca aso escape thephagosome105 ad modate other macrophage defecesto promote its sria106,107. Phagosoma escape, a prei-osy appreciated facet of itracearM. tuberculo-sis, reqires the expressio of a oe bacteria secretiosystem, ESX105, hich is ackig i airet mycobacte-ria(reieed i REF. 108). Phagocytosis ofM. tuberculo-sis by macrophages occrs throgh the egagemet of

arios receptors, icdig CR3 (REF. 109). Hoeer,ike other partices that are egfed by the samereceptors, theMycobacterium-cotaiig phagosomefais to progress ad become a phagoysosome ad isistead arrested at a eary stage110(FIG. 3a). Arrested M. tuberculosis-cotaiig phagosomes are charac-terized by the presece of Rab5A, bt the recritmetof Rab5A effectors, sch as EEA1 ad hvPS34, isimpaired110,111, ad as a rest, PI(3)P does ot acc-mate. M. tuberculosis ses a rage of protei adipid effectors to ater PI(3)P sigaig112,113(TABLE 2).The mycobacteria phosphoiositide ipoarabioma-a112, a compoet of the ce a that is shed from

ie bacteria ad becomes distribted throghot theedocytic etork114,preets the icrease i cytosoic[Ca2+] that ormay accompaies phagocytosis ad thatis thoght to be reqired to actiate hvPS34 throghcamodi112.M. tuberculosis frther impairs cytosoicCa2+ fx by ihibitig sphigosie kiase, hich co-

erts sphigosie to sphigosie-1-phosphate, hich itr promotes Ca2+ effx from the edopasmic retic-m (ER)115,116.M. tuberculosis aso prodces the phos-phatase SapM, hich specificay hydroyses PI(3)P113.This combied strategy effectiey depetes PI(3)P fromeary phagosomes ad preets the trasitio to the atead phagoysosoma stages.

Table 1 | Proteins and peptides with antimicrobial activity

Atma att Pte pepte res

Bacteriostatic

Nutrient deprivation Lactoferrin 71

NRAMP1 (also known as SLC11A1) 72

Bactericidal

Membranepermeabilization

Defensins 73

Cathelicidins 74

Hydrolysis

Carbohydrates Lysozyme 158

-hexosaminidase 159

-glucuronidase 159

Lipids Phospholipase A2 160

Proteins Cysteine proteases*: cathepsins B, C, H, K, L, O,S and W

159,161

Aspartate proteases*: cathepsins D and E 159,161

Serine proteases*: cathepsin G 159,161

Carboxypeptidases: lysosomal carboxypeptidase(cathepsin A), cathepsin B (dipeptidase), cathepsinX, lysosomal carboxypeptidase B, prolylcarbox-ypeptidase and peptidyl dipeptidase B

159,161

Aminopeptidases: cathepsin H, dipeptidylpeptidase I (cathepsin C), dipeptidyl peptidase IIand tripeptidyl peptidase

159,161

*Endopeptidases. Exopeptidases. NRAMP1, natural resistance-associated macrophage protein 1.

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a Mycobacterium tuberculosis d Coxiella burnetiib Legionella pneumophila c Listeria monocytogenes

PIM

LAM

?

SapM

PIPIM

hVPS34EEA1

Ca2+

Nucleus Nucleus

ER-derived

vesicle

DrrA

Rab1ARF1

GDI

LidA

RalF

Nucleus

LLO

Ca2+ or H+

PlcA

PlcB

Nucleus

APV LC3

V-ATPase

Delayed

Rab5

Earlyendosome

Trans-Golginetwork

ER

Lateendosome

Lysosome

ActA

LC3

LC3

Rab7

Actiatio of macrophages icreases their abiity toeradicate itracearM. tuberculosis ad other orga-isms117,118. This is highighted by the obseratio thatiterfero- (IFn)-stimated macrophages demo-strate ehaced bacteria cearace; i stimated ces,M. tuberculosis-cotaiig phagosomes are seqes-tered by atophagic compartmets that timateyfse ith ysosomes119. This atophagic respose cabe ehaced by To-ike receptor igads120 ad the

actiatio of immity-reated p47 gaosie triphos-phatase protei121. Immity to pathoges sch as myco-bacteria is i part attribtabe to the actiatio of theifammasome, a mtiprotei compex that faciitatesthe kiig of itracear bacteria ad is reqired foritereki-1 (I-1) processig. I-1 eabes mac-rophages to oercome the arrested matratio of theM. tuberculosis -cotaiig phagosome122,123 throgh ako mechaism that may ioe restored PI(3)Pprodctio ad sbseqet matratio of the phago-some. Iterestigy, the bacteria hae aso eoed a ayto coteract the ifammatory respose: M. tubercu-losis secretes ZmpA, a predicted zic metaoprotease

that ihibits I-1 processig by the host ces123.Itracear sria of the bacteria therefore depedso a ogoig, mtiee tg of ar betee the patho-ge ad host macrophage.

L. monocytogenes: a phagosomal escape artist. isteriosis,a potetiay fata disease cased by the Gram-positiebacterim L. monocytogenes124, is freqety cotractedthrogh the cosmptio of cotamiated foods.

L.monocytogenes is iteraized by both o-phagocyticces ad professioa phagocytes124, hich is crcia forbacteria propagatio ad dissemiatio. uptake by epi-theia ces is mediated by the srface proteis iteraiA ad iterai B (IA125 ad IB126), hich fc-tio as igads for the adhesio moece E cadheri 127,the hepatocyte groth factor receptor Met128 ad thecompemet receptor, C1qR129. Hoeer, phagocytosisofL. monocytogenes by macrophages is mediated byscaeger receptors that recogize ipoteichoic acid, acompoet of the Gram-positie bacteria ce a130.I additio, the srface ofL. monocytogenes ca becomedecorated ith the compemet compoets C1q131 ad

Figure 3 | Statees use pessa taeua atea pates t muate pasme matuat.

a | M. tuberculosis. After internalization, the bacterium uses an array of effector molecules, including the lipids phosphati-

dylinositol mannoside (PIM) and lipoarabinomannan (LAM), and the phosphatidylinositol-3-phosphate (PI(3)P)

phosphatase SapM to arrest phagosome maturation at an early stage. | L. pneumophila. This bacterium impairs fusion of

theLegionella-containing vacuole with endolysosomal compartments, and instead promotes fusion with endoplasmic

reticulum (ER)-derived membranes. | L. monocytogenes. This pathogen evades phagolysosomal fusion after

internalization by escaping the phagosome through secretion of listeriolysin O (LLO) and two phospholipases, PlcA and

PlcB. Once in the cytoplasm, L. monocytogenes replicates and becomes motile by using actin comet tails generated by the

effector ActA. |C. burnetii. Phagosomes containing this bacterium undergo delayed maturation as they fuse with

autophagocytic vesicles (APVs) bearing LC3. The delay enables C. burnetii to acquire features that allow it to replicate in amembrane-bound compartment that resembles phagolysosomes. EEA1, early endosome antigen 1; GDI, guanine

nucleotide dissociation inhibitor; LAM, lipoarabinomannan.

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Autophagy

A complex cellular process by

which intracellular

components, including entire

organelles, are sequestered in

double-membrane vesicles or

vacuoles called

autophagosomes that

eventually fuse with lysosomes,

bringing about the degradation

of their contents.

C3 (REF. 132), hich are igads for macrophage compe-met receptors. asty, IB aso fctios as a igad forthe C1q receptor129.

L. monocytogenes, a factatie itracear patho-ge, sries itraceary by modifyig ad sbse-qety escapig from phagosomes (FIG. 3c). To this ed,the bacteria se a sophisticated combiatio of effec-tors. The choestero-depedet cytoysi isterioysiO (O) creates pores i the phagosoma membrae aseary as 5 mites after ifectio133. The effect of O isrestricted to the phagosome, as it eeds to be actiatedby acidificatio ad/or by the host ezyme GIT (IFn-idcibe ysosoma thio redctase) that is fod isidethe phagosome134. Secretio of O ihibits the matra-tio of phagosomes135 oig to a oss of mia H+ adCa2+,hich are thoght to be reqired for fsio ithedosomes ad/or ysosomes136. Listeria aso expressesto membrae-actie phosphoipase C ezymes, phos-phoiosito-specific phosphoipase C (PI-PC; ecodedbyplcA) ad broad-rage phosphoipase C (PC-PC;ecoded byplcB). Together ith O, PI-PC ad

PC-PC case the breakdo of the membrae of theL.monocytogenes-cotaiig phagosome ad therebyeabe the bacteria to escape ad take p residece ithe cytoso136,137, here bacteria repicatio occrs138.

Cytosoic L. monocytogenes repicates efficiety,ad has a geeratio time of ~30 mites, oig tothe expressio of gees that eabe triets to be seddirecty from the host ce139. I the cytoso, L. mono-cytogenes becomes motie by srpig the hosts acticytoskeeta machiery. The bacteria srface proteiActA idces the assemby of spectacar acti comettais by recritig host ce Arp2/3 compexes, G actiad asodiator-stimated phosphoprotei (vASP)

famiy members (reieed i REF. 140). Athogh thismotiity is ot reqired for phagosoma escape, ActA co-tribtes sbstatiay to L. monocytogenes dissemiatiodrig ifectio141.

Athogh L. monocytogenes as preiosy thoghtto reside primariy i the cytoso, der some cir-cmstaces, it repicates i macrophages, iside arge,AMP1-positie acoes caed spacios Listeria-cotaiig phagosomes (SAPs)142. The formatio ofSAPs is stricty depedet o o ees of O prodc-tio ad the recritmet of the autophagy protei C3to the phagosome142. SAP formatio i macrophagesaos L. monocytogenes to repicate soy (geeratiotime >8 hors) ithot destroyig the ifected ce142.This ey discoered facet of the L. monocytogenes ifecyce cod cotribte to the deeopmet of chroicL. monocytogenes ifectios.

L. pneumophila: reprogramming the phagosomal mat-uration pathway. L. pneumophila is a Gram-egatiebacterim that is fod biqitosy i aqatic eiro-

mets, groig i biofims or ithi freshater proto-zoa143. I hmas, it ca srie ad repicate ithiprofessioa phagocytes144 by redirectig the matra-tio of phagosomes to create a iqe itracear ichesited for bacteria repicatio (FIG. 3b).

After ihaatio ofL. pneumophila, the major otermembrae protei o the srface of the bacteria effec-tiey fixes compemet145, thereby promotig phagocyto-sis by macrophages throgh compemet receptors146 adeadig to the formatio ofLegionella-cotaiig acoes(Cvs). Iteraized L. pneumophila rapidy modatesthe matratio of the Cv, aoidig iteractio ith thedefat edoysosoma pathay147,148. Shorty afterards,

Table 2 | Effector molecules that contribute to the survival of professional intracellular bacterial pathogens

Pate Eet ceua taet Eet ut res

Mycobacteriumtuberculosis

SapM PI(3)P Hydrolyses PI(3)P to PI, thereby inhibiting phagosomalmaturation

105

ZmpA Inflammasome Blocks processing of IL-1 110

Phosphatidylinositol

mannoside

Endosomal pathway Mechanism unknown, but promotes fusion of endosomes

with M. tuberculosis-containing phagosomes

162

Lipoarabinomannan Unknown Blocks cytosolic Ca2+ fluxes, impairing hVPS34 activation 104

Legionellapneumophila

Drra (also known as SidM) Rab1 GDI and Rab1 Displaces Rab1 from host GDI and functions as Rab1 GEF 121,122

LidA Rab1 Binds Rab1 to enhance recruitment of activated Rab1 to LCV 119

RalF ARF1 ARF1-specific GEF that activates ARF1 123

LepB Rab1 Rab1 GAP that promotes GTP hydrolysis 121

Listeriamonocytogenes

Listeriolysin O Phagosomalmembrane

Generates pores to perturb ion gradients and facilitateescape 138,141

Phospholipase (PlcA) Phagosomalmembrane

Phosphoinositol-specific phospholipase that facilitatesphagosome escape

142

Phospholipase (PlcB) Phagosomalmembrane

Broad range phospholipase that facilitates escape 142

Coxiellaburnetii

Largely unknown; AnkF wasrecently identified as a type IVsecretion system protein

Unknown Type IV secretion system-secreted effector with ankyrinrepeat motifs

124

GAP, GTPase-activating protein; GEF, guanine nucleotide exchange factor; GDI, guanine nucleotide dissociation inhibitor; IL, interleukin; LCV, Legionella-containing vacuole; PI(3)P, phosphatidylinositol-3-phosphate.

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SarICOPII-coated

secretory vesicle

A vesicle derived from the

endoplasmic reticulum (ER)

through coating with thecoatomer protein complex II

(COPII) protein complex, a

process initiated at specialized

ER exit sites by the GTPase SarI.

Type IV secretion system

A macromolecular apparatus

used by bacteria to secrete

effector molecules. This

secretion system is ancestrally

related to bacterial DNA

conjugation systems, and is

often expressed by pathogenic

bacteria, which contributes to

their virulence.

SarICOPII-coated secretory vesicles deried from the ERfse ith the Cv i a process that i part reqires thehost ce GTPase Rab1, hich, together ith aother hostGTPase, ARF1, regates esicar trasport betee theER ad the Gogi compex. The extet ad timig of Rab1recritmet to the Cv are tighty regated throgheffector proteis deiered by the DotIcm type IV secretionsystem (T4SS)149. The T4SS effector DrrA150 (aso koas SidM151) bids i a phosphatidyiosito-4-phosphate-depedet maer to the Cv152, ad dispaces thegaie ceotide dissociatio ihibitor that stabiizesthe GDP-bod form of Rab1 (REFS 153,154). DrrA asofaciitates ceotide exchage150,151, geeratig the actie,GTP-bod form of Rab1, hich is reqired for esic-ar fsio. A secod T4SS effector, idA, fctios sy-ergisticay ith DrrA to ehace Rab1 recritmet tothe Cv151. SbseqetyepB, aother T4SS effector,deactiates Rab1 by promotig GTP hydroysis153.

L. pneumophila aso maipates the actiity ofARF1 throgh the T4SS effector RaF, hich operatesas a ARF1-specific GEF155. Together, DrrA, idA ad

RaF recrit actie Rab1 ad ARF1 to the Cv, therebypromotig ad regatig the fsio of ER-deried

esices to the Cv150,153,155. As the ER-deried esicesiteract ith the Cv, L. pneumophila simtaeosydisrpts the orma microtbe-depedet orgae-ar trasport of the host ce throgh the secretio ofadditioa irece factors, sch as AkX156. It is ote-orthy that mtats ackig DrrA or RaF ca sriei macrophages, impyig that mtipe, reddatmechaisms ca ead to formatio of the Cv. L. pneu-mophila therefore possesses a ast, icompetey char-acterized arsea of effectors that pertrb may aspectsof esicar trasport i host ces.

utimatey, L. pneumophila repicates itracearyithi a arge, acidic acoe ith some of the proper-ties of ysosomes157,158. Athogh there is disagreemetas to hether the acidificatio is reqired for efficietrepicatio158,159, it is cear that fsio ith the ER iscrcia to ao the bacteria sfficiet time to deeopresistace to the acoar eiromet. Iteractio ofER-deried membraes ith the Cv has bee associ-ated ith host ce atophagy160, ad it has bee sg-gested that L. pneumophila ca deay atophagoysosomeformatio, aoig ehaced sria161.

The effectors discssed aboe are oy a fractio ofthose reqired for sccessf cmiatio of the bacteriarepicatio process. More tha 80 differet T4SS effectors

hae bee impicated162, i additio to seera other pro-teis that are secreted by the bacteria throgh IcmDot-idepedet mechaisms163. Seera of these effectorspossess motifs that are commoy idetified i ekaryoticproteis, sggestig that L. pneumophila has the potetiato maipate additioa host ce processes156,163.

C. burnetii: weathering the storm.C. burnetii, the casa-tie aget of Q feer, is a highy ifectios, Gram-egatie,obigate itracear pathoge164. It has a biphasic deeop-meta cyce that cosists of a ifectios sma-ce ariat(phase 1 Coxiella) ad a arge-ce ariat (phase 2 Coxiella)that repicates itraceary164. I cotrast to the other

itracear bacteria pathoges described aboe, C. bur-netii resides i a acidified ysosome-ike compartmet, ihich it repicates i the presece of seera atimicrobiafactors165 (FIG. 3d).

Phagocytosis of phase I Coxiella occrs after egage-met by the bacterim of the ekocyte resposeitegri (v3)166, hich actiates a ce sigaigcascade that timatey idces ocaized acti poym-erizatio167, propeig iteraizatio ad formatio ofthe Coxiella phagosome. By cotrast, iteraizatioof airet phase II Coxiella, throgh egagemet ofv3, CR3 or throgh hydrophobic bidig mediatedby the bacteria ipopoysaccharide164, does ot eicit thesame sigaig cascade168.

After seaig, the Coxiella phagosome iteractsith the defat edocytic pathay165. Simtaeosy,C. burnetii begis to ater the matratio programme,thereby coferrig properties of atophagosomes tothe acoe169,170. Specificay, the atophagic proteiC3 is recrited to the Coxiella phagosome, deayigits fsio ith ysosomes171 ad giig the bacteria time

to iitiate the trasitio to the repicatio-competet,arge-ce ariat170.

withi 48 hors of ifectio, C. burnetii resides ia arge spacios compartmet that cotais seeraysosoma proteis, icdig the v-ATPase165. Thiscompartmet, termed the repicatie Coxiella acoe,is acidic (pH 4.8)172, hich isa reqiremet for C. bur-netii repicatio165, ee thogh acidificatio is ormaythoght to be a importat bacteriostatic or bactericidacompoet of the phagoysosome. Physioogica std-ies ofC. burnetii reea that it behaes simiary to aacidophie, as it reqires a o pH for certai metaboicactiities173. withi the repicatie acoe, the bacteriaaso ecoter other atimicrobia agets. Yet C. burnetiiseems to be e adapted to this bioogica iche, adprobaby ses a assortmet of irece factors to -ify the atimicrobia effects. Most of these factors remaito be idetified, bt oe ko exampe is the idctioof the SOS DnA repair system that protects the pathogefrom chromosoma damage oig to ROS exposre174.Simiary to L. pneumophila, C. burnetii aso ecodes afctioa T4SS. Frthermore, the recet idetificatioof seera cadidate effectors ith akyri-repeat homo-ogy domais156 i stimate a ee greater iterest iC. burnetii pathogeesis.

Concluding remarks

The cofece of microbioogy ad ce bioogy asmade possibe to a arge extet by the deeopmet ofbiochemica ad imagig techiqes that improed thesesitiity ad spatio-tempora resotio of eets thattake pace drig the ifectios seqece. Ecidatioof the f geome seqeces of a mber of pathoges,together ith the icreased sesitiity ad accracy ofproteomic aayses ad the impemetatio of poer-f itraita imagig i frther acceerate the paceof koedge acqisitio i the e discipie of ce-ar microbioogy. As a coseqece, more fasciatigisights ito the iteractio betee phagocytes adpathoges are certai to emerge.

R E V I E W S



http://www.uniprot.org/uniprot/Q29ST3http://www.uniprot.org/uniprot/Q5X6G3http://www.uniprot.org/uniprot/Q5ZSM7http://www.uniprot.org/uniprot/Q8RT31http://www.uniprot.org/uniprot/Q8RT31http://www.uniprot.org/uniprot/Q5ZSM7http://www.uniprot.org/uniprot/Q5X6G3http://www.uniprot.org/uniprot/Q29ST3


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1. Roitt, I. M. Essential Immunology (Blackwell Science,

Oxford, 1994).2. Ghazizadeh, S., Bolen, J. B. & Fleit, H. B. Physical and

functional association of Src-related protein tyrosine

kinases with FcRII in monocytic THP-1 cells.J. Biol.

Chem.269, 88788884 (1994).

3. Daron, M. Fc receptor biology.Annu. Rev. Immunol.

15, 203234 (1997).

4. Caron, E. & Hall, A. Identification of two distinct

mechanisms of phagocytosis controlled by different

Rho GTPases. Science282, 17171721 (1998).

5. Patel, J. C., Hall, A. & Caron, E. Vav regulatesactivation of Rac but not Cdc42 during FcR-mediated

phagocytosis. Mol. Biol. Cell13,

12151226 (2002).

6. Hall, A. B. et al. Requirements for Vav guanine

nucleotide exchange factors and Rho GTPases in FcR-

and complement-mediated phagocytosis. Immunity

24, 305316 (2006).

This article refutes the prevailing view concerning

Rho GTPases during phagocytosis. It also shows

that Rac regulates actin polymerization during both

Fc- and complement-mediated phagocytosis and

that Rho is implicated in both modes of uptake, but

at a step distinct from actin polymerization.

7. Coppolino, M. G. et al. Evidence for a molecular

complex consisting of Fyb/SLAP, SLP-76, Nck, VASP

and WASP that links the actin cytoskeleton to Fc

receptor signalling during phagocytosis.J. Cell Sci.

114, 43074318 (2001).8. May, R. C. et al. Involvement of the Arp2/3 complex in

phagocytosis mediated by FcR or CR3. Nature Cell

Biol.2, 246248 (2000).9. Colucci-Guyon, E. et al. A role for mammalian

diaphanous-related formins in complement receptor

(CR3)-mediated phagocytosis in macrophages. Curr.

Biol.15, 20072012 (2005).10. Araki, N., Johnson, M. T. & Swanson, J. A. A role for

phosphoinositide 3-kinase in the completion of

macropinocytosis and phagocytosis by macrophages.

J. Cell Biol.135, 12491260 (1996).

11. Cox, D. et al. Myosin X is a downstream effector of

PI(3)K during phagocytosis. Nature Cell Biol.4,

469477 (2002).

12. Lennartz, M. R. et al. Phospholipase A2 inhibition

results in sequestration of plasma membrane into

electronlucent vesicles during IgG-mediated

phagocytosis.J. Cell Sci. 110, 20412052 (1997).

13. Kusner, D. J., Hall, C. F. & Jackson, S. Fc receptor-

mediated activation of phospholipase D regulates

macrophage phagocytosis of IgG-opsonized particles.

J. Immunol.162, 22662274 (1999).

14. Holevinsky, K. O. & Nelson, D. J. Membranecapacitance changes associated with particle uptake

during phagocytosis in macrophages. Biophys. J.75,

25772586 (1998).

15. Bajno, L. et al. Focal exocytosis of VAMP3-containing

vesicles at sites of phagosome formation.J. Cell Biol.

149, 697706 (2000).

16. Braun, V. et al. TIVAMP/VAMP7 is required for

optimal phagocytosis of opsonised particles in

macrophages. EMBO J.23, 41664176 (2004).

17. Czibener, C. et al. Ca2+ and synaptotagmin VII-

dependent delivery of lysosomal membrane to

nascent phagosomes.J. Cell Biol.174, 9971007

(2006).

18. Huynh, K. K. et al. Fusion, fission, and secretion

during phagocytosis. Physiology (Bethesda)22,

366372 (2007).

19. Cox, D. et al. A Rab11-containing rapidly recycling

compartment in macrophages that promotes

phagocytosis. Proc. Natl Acad. Sci. USA97, 680685

(2000).20. Niedergang, F. et al. ADP ribosylation factor 6 is

activated and controls membrane delivery during

phagocytosis in macrophages.J. Cell Biol.161,

11431150 (2003).

21. Desjardins, M. et al. Biogenesis of phagolysosomes

proceeds through a sequential series of interactions

with the endocytic apparatus.J. Cell Biol.124,

677688 (1994).

22. Mayorga, L. S., Bertini, F. & Stahl, P. D. Fusion of

newly formed phagosomes with endosomes in intact

cells and in a cell-free system.J. Biol. Chem.266,

65116517 (1991).23. Desjardins, M. et al. Maturation of phagosomes is

accompanied by changes in their fusion properties and

size-selective acquisition of solute materials from

endosomes.J. Cell Sci. 110, 23032314 (1997).

24. Mukherjee, S., Ghosh, R. N. & Maxfield, F. R.

Endocytosis. Physiol. Rev.77, 759803 (1997).

25. Bucci, C. et al. The small GTPase rab5 functions as a

regulatory factor in the early endocytic pathway. Cell

70, 715728 (1992).

26. Kitano, M. et al. Imaging of Rab5 activity identifies

essential regulators for phagosome maturation.

Nature453, 241245 (2008).

This article shows thatGAPVD1 is the essential GEF

for Rab5A activation during the phagocytosis of

apoptotic cells and that its phagosomal delivery is

mediated by MAPRE1 (microtubule-associated

protein RP/EB family member 1) on microtubules.

27. Vieira, O. V. et al. Distinct roles of class I and class IIIphosphatidylinositol 3-kinases in phagosome

formation and maturation.J. Cell Biol.155, 1925

(2001).

28. Gaullier, J. M. et al. FYVE fingers bind PtdIns(3)P.

Nature394, 432433 (1998).

29. Kanai, F. et al. The PX domains of p47phox and

p40phox bind to lipid products of PI(3)K. Nature Cell

Biol.3, 675678 (2001).

30. Lawe, D. C. et al. The FYVE domain of early endosome

antigen 1 is required for both phosphatidylinositol

3-phosphate and Rab5 binding. Critical role of this

dual interaction for endosomal localization.J. Biol.

Chem.275, 36993705 (2000).

31. Callaghan, J. et al. Direct interaction of EEA1 with

Rab5b. Eur. J. Biochem.265, 361366 (1999).

32. McBride, H. M. et al. Oligomeric complexes link Rab5

effectors with NSF and drive membrane fusion via

interactions between EEA1 and syntaxin 13. Cell98,

377386 (1999).

33. Mills, I. G., Urb, S. & Clague, M. J. Relationships

between EEA1 binding partners and their role in

endosome fusion.J. Cell Sci.114, 19591965 (2001).

34. Botelho, R. J. et al. Role of COPI in phagosome

maturation.J. Biol. Chem.275, 1571715727

(2000).

35. Leiva, N. et al. Reconstitution of recycling from the

phagosomal compartment in streptolysin O-

permeabilized macrophages: role of Rab11.

Exp. Cell Res.312, 18431855 (2006).

36. Damiani, M. T. et al. Rab coupling protein associates

with phagosomes and regulates recycling from the

phagosomal compartment. Traffic5, 785797

(2004).

37. Lindsay, A. J. et al. Rab coupling protein (RCP), a novel

Rab4 and Rab11 effector protein.J. Biol. Chem.277,

1219012199 (2002).

38. Soldati, T. & Schliwa, M. Powering membrane traffic in

endocytosis and recycling. Nature Rev. Mol. Cell Biol.

7, 897908 (2006).

39. Gokool, S., Tattersall, D. & Seaman, M. N. J. EHD1

interacts with retromer to stabilize SNX1 tubules andfacilitate endosome-to-Golgi retrieval. Traffic8,

18731886 (2007).

40. Traer, C. J. et al. SNX4 coordinates endosomal sorting

of TfnR with dynein-mediated transport into the

endocytic recycling compartment. Nature Cell Biol.9,

13701380 (2007).

41. Lee, W. L. et al. Role of ubiquitin and proteasomes in

phagosome maturation. Mol. Biol. Cell16,

20772090 (2005).

42. Muzio, T. et al. Structural basis for budding by the

ESCRT-III factor CHMP3. Dev. Cell10, 821830

(2006).

43. Hanson, P. I. et al. Plasma membrane deformation by

circular arrays of ESCRT-III protein filaments.J. Cell

Biol.180, 389402 (2008).

44. Whitley, P. et al. Identification of mammalian Vps24p

as an effector of phosphatidylinositol

3,5-bisphosphate-dependent endosome

compartmentalization.J. Biol. Chem.278,

3878638795 (2003).45. Bucci, C. et al. Rab7: a key to lysosome biogenesis.

Mol. Biol. Cell11, 467480 (2000).

46. Harrison, R. E. et al. Phagosomes fuse with late

endosomes and/or lysosomes by extension of

membrane protrusions along microtubules: role of

Rab7 and RILP. Mol. Cell Biol.23, 64946506

(2003).

47. Rink, J. et al. Rab conversion as a mechanism of

progression from early to late endosomes. Cell122,

735749 (2005).

Rink and colleagues used advanced quantitative

live-cell imaging to show that early-to-late

endosomal maturation requires the gradual

exchange of Rab5A for Rab7A (Rab conversion) on

the same organelle.

48. Peterson, M. R. & Emr, S. D. The class C Vps complex

functions at multiple stages of the vacuolar transport

pathway. Traffic2, 476486 (2001).

49. Poupon, V. et al. The role of mVps18p in clustering,

fusion, and intracellular localization of late endocytic

organelles. Mol. Biol. Cell14, 40154027 (2003).

50. Jordens, I. et al. The Rab7 effector protein RILP

controls lysosomal transport by inducing the

recruitment of dyneindynactin motors. Curr. Biol.11,

16801685 (2001).

51. Antonin, W. et al. A SNARE complex mediating fusion

of late endosomes defines conserved properties of

SNARE structure and function. EMBO J.19,

64536464 (2000).

52. Wade, N. et al. Syntaxin 7 complexes with mouseVps10p tail interactor 1b, syntaxin 6, vesicle-

associated membrane protein (VAMP)8, and VAMP7

in b16 melanoma cells.J. Biol. Chem.276,

1982019827 (2001).53. Vieira, O. V. et al. Modulation of Rab5 and Rab7

recruitment to phagosomes by phosphatidylinositol

3-kinase. Mol. Cell. Biol.23, 25012514 (2003).54. Odorizzi, G. The multiple personalities of Alix.J. Cell

Sci.119, 30253032 (2006).

55. Kobayashi, T. et al. A lipid associated with the

antiphospholipid syndrome regulates endosome

structure and function. Nature392, 193197

(1998).

56. Gillooly, D. J. et al. Localization of phosphatidylinositol

3-phosphate in yeast and mammalian cells. EMBO J.

19, 45774588 (2000).

57. Griffiths, G. et al. The mannose 6-phosphate receptor

and the biogenesis of lysosomes. Cell52, 329341

(1988).

58. Beyenbach, K. W. & Wieczorek, H. The V-type H+

ATPase: molecular structure and function,

physiological roles and regulation.J. Exp. Biol.209,

577589 (2006).

59. Huynh, K. K. & Grinstein, S. Regulation of vacuolar pH

and its modulation by some microbial species.

Microbiol. Mol. Biol. Rev.71, 452462 (2007).

60. van Deurs, B., Holm, P. K. & Sandvig, K. Inhibition of

the vacuolar H+-ATPase with bafilomycin reduces

delivery of internalized molecules from mature

multivesicular endosomes to lysosomes in HEp-2 cells.

Eur. J. Cell Biol.69, 343350 (1996).61. Gordon, A. H., Hart, P. D. & Young, M. R. Ammonia

inhibits phagosomelysosome fusion in macrophages.

Nature286, 7980 (1980).

62. Aniento, F. et al. An endosomal COP is involved in

the pH-dependent formation of transport vesicles

destined for late endosomes.J. Cell Biol.133, 2941

(1996).63. Hurtado-Lorenzo, A. et al. V-ATPase interacts with

ARNO and Arf6 in early endosomes and regulates the

protein degradative pathway.Nature Cell Biol.8,124136 (2006).

The authors found that the intraluminal domains of

two a subunits of the V-ATPase function as low pH

sensors that undergo a conformational change in

response to acidification and bind to ARF6 and its

GEF, cytohesin 2, to regulate the endocytic

degradative pathway.

64. Babior, B. M. NADPH oxidase. Curr. Opin. Immunol.

16, 4247 (2004).

65. Heyworth, P. G., Cross, A. R. & Curnutte, J. T. Chronic

granulomatous disease. Curr. Opin. Immunol.15,

578584 (2003).

66. Ambruso, D. R. et al. Human neutrophil

immunodeficiency syndrome is associated with an

inhibitory Rac2 mutation. Proc. Natl Acad. Sci. USA

97, 46544659 (2000).

67. Zhao, X., Carnevale, K. A. & Cathcart, M. K. Human

monocytes use Rac1, not Rac2, in the NADPH oxidase

complex.J. Biol. Chem.278, 4078840792 (2003).

68. Quinn, M. T. & Gauss, K. A. Structure and regulationof the neutrophil respiratory burst oxidase:

comparison with nonphagocyte oxidases.J. Leukoc.

Biol.76, 760781 (2004).

69. Minakami, R. & Sumimotoa, H. Phagocytosis-coupled

activation of the superoxide-producing phagocyte

oxidase, a member of the NADPH oxidase (nox)

family. Int. J. Hematol.84, 193198 (2006).

70. Shepherd, V. L. The role of the respiratory burst of

phagocytes in host defense. Semin. Respir. Infect.1,

99106 (1986).

71. Reeves, E. P. et al. Killing activity of neutrophils is

mediated through activation of proteases by K+ flux.

Nature416, 291297 (2002).

72. Reeves, E. P. et al. Reassessment of the microbicidal

activity of reactive oxygen species and hypochlorous

acid with reference to the phagocytic vacuole of the

neutrophil granulocyte.J. Med. Microbiol.52,

643651 (2003).

R E V I E W S


R E V I E W S



11/12

73. DeCoursey, T. E. During the respiratory burst, do

phagocytes need proton channels or potassium

channels, or both? Sci. STKE2004, pe21 (2004).

74. Fang, F. C. Antimicrobial reactive oxygen and nitrogen

species: concepts and controversies. Nature Rev.

Microbiol.2, 820832 (2004).

75. Stuehr, D. J. Mammalian nitric oxide synthases.

Biochim. Biophys. Acta1411, 217230 (1999).

76. Webb, J. L. et al. Macrophage nitric oxide synthase

associates with cortical actin but is not recruited to

phagosomes. Infect. Immun.69, 63916400 (2001).

77. De Groote, M. A., Fang, F. G. Nitric oxide andInfection (Kluwer AcademicPlenum, New York,

1999).

78. Borregaard, N. et al. Granules and secretory vesicles

of the human neutrophil. Clin. Exp. Immunol.101

(Suppl. 1), 69 (1995).

79. Masson, P. L., Heremans, J. F. & Schonne, E.

Lactoferrin, an iron-binding protein in neutrophilic

leukocytes.J. Exp. Med.130, 643658 (1969).

80. Cellier, M. F., Courville, P. & Campion, C. Nramp1

phagocyte intracellular metal withdrawal defense.

Microbes Infect.9, 16621670 (2007).

81. Lehrer, R. I., Lichtenstein, A. K. & Ganz, T. Defensins:

antimicrobial and cytotoxic peptides of mammalian

cells.Annu. Rev. Immunol.11, 105128 (1993).82. Zanetti, M. The role of cathelicidins in the innate host

defenses of mammals. Curr. Issues Mol. Biol.7,

179196 (2005).

83. Pillay, C. S., Elliott, E. & Dennison, C. Endolysosomal

proteolysis and its regulation. Biochem. J.363,

417429 (2002).

84. Claus, V. et al. Lysosomal enzyme trafficking between

phagosomes, endosomes, and lysosomes in J774

macrophages. Enrichment of cathepsin H in early

endosomes.J. Biol. Chem.273, 98429851 (1998).

85. Garrity-Ryan, L. et al. The arginine finger domain of

ExoT contributes to actin cytoskeleton disruption and

inhibition of internalization ofPseudomonas

aeruginosa by epithelial cells and macrophages.

Infect. Immun.68, 71007113 (2000).

86. Grosdent, N. et al. Role of Yops and adhesins in

resistance ofYersinia enterocolitica to phagocytosis.

Infect. Immun.70, 41654176 (2002).

87. Rooijakkers, S. H. M. et al. Immune evasion by a

staphylococcal complement inhibitor that acts on C3

convertases. Nature Immunol.6, 920927 (2005).88. Hong, Y. Q. & Ghebrehiwet, B. Effect ofPseudomonas

aeruginosa elastase and alkaline protease on serum

complement and isolated components C1q and C3.

Clin. Immunol. Immunopathol.62, 133138 (1992).

89. Prasadarao, N. V. et al. A novel interaction of outer

membrane protein A with C4b binding proteinmediates serum resistance ofEscherichia coliK1.

J. Immunol.169, 63526360 (2002).

90. Davis, J. M., Rasmussen, S. B. & OBrien, A. D.

Cytotoxic necrotizing factor type 1 production by

uropathogenic Escherichia colimodulates

polymorphonuclear leukocyte function. Infect. Immun.

73, 53015310 (2005).

91. Vandal, O. H. et al. A membrane protein preserves

intrabacterial pH in intraphagosomal Mycobacterium

tuberculosis. Nature Med.14, 849854 (2008).

92. Park, Y. K. et al. Internal pH crisis, lysine

decarboxylase and the acid tolerance response of

Salmonella typhimurium. Mol. Microbiol.20,

605611 (1996) .93. Schmidtchen, A. et al. Proteinases of common

pathogenic bacteria degrade and inactivate the

antibacterial peptide LL-37. Mol. Microbiol.46,

157168 (2002).94. Peschel, A. et al.Staphylococcus aureus resistance to

human defensins and evasion of neutrophil killing viathe novel virulence factor MprF is based on

modification of membrane lipids with l-lysine.J. Exp.

Med.193, 10671076 (2001).

95. Trent, M. S. et al. An inner membrane enzyme in

Salmonella and Escherichia colithat transfers

4-amino-4-deoxy-l-arabinose to lipid A: induction on

polymyxin-resistant mutants and role of a novel lipid-

linked donor.J. Biol. Chem.276, 4312243131

(2001).

96. St John, G. et al. Peptide methionine sulfoxide

reductase from Escherichia coliand Mycobacterium

tuberculosis protects bacteria against oxidative

damage from reactive nitrogen intermediates. Proc.

Natl Acad. Sci. USA98, 99019906 (2001).

97. Ng, V. H. et al. Role of KatG catalase-peroxidase in

mycobacterial pathogenesis: countering the phagocyte

oxidative burst. Mol. Microbiol.52, 12911302

(2004).

98. Mott, J., Rikihisa, Y. & Tsunawaki, S. Effects of

Anaplasma phagocytophilaon NADPH oxidase

components in human neutrophils and HL-60 cells.

Infect. Immun.70, 13591366 (2002).

99. Davis, A. S. et al. Mechanism of inducible nitric oxide

synthase exclusion from mycobacterial phagosomes.

PLoS Pathog.3, e186 (2007).

100. Luo, M., Fadeev, E. A. & Groves, J. T. Mycobactin-

mediated iron acquisition within macrophages. Nature

Chem. Biol.1, 149153 (2005).

101. Velayudhan, J. et al. The role of ferritins in the

physiology ofSalmonella enterica sv. Typhimurium: aunique role for ferritin B in ironsulphur cluster repair

and virulence. Mol. Microbiol.63, 14951507

(2007).

102. Robey, M. & Cianciotto, N. P. Legionella pneumophila

feoAB promotes ferrous iron uptake and intracellular

infection. Infect. Immun.70, 56595669 (2002).

103. Raivio, T. L. Envelope stress responses and Gram-

negative bacterial pathogenesis. Mol. Microbiol.56,

11191128 (2005).

104. Pethe, K. et al. Isolation ofMycobacterium

tuberculosis mutants defective in the arrest of

phagosome maturation. Proc. Natl Acad. Sci. USA

101, 1364213647 (2004).

105. Wel, N. V. D. et al.M. tuberculosis and M. leprae

translocate from the phagolysosome to the cytosol in

myeloid cells. Cell129, 12871298 (2007).

106. Gan, H. et al.Mycobacterium tuberculosis blocks

crosslinking of annexin-1 and apoptotic envelope

formation on infected macrophages to maintain

virulence. Nature Immunol.9, 11891197 (2008).

107. Rao, V. et al.Mycobacterium tuberculosis controls

host innate immune activation through cyclopropane

modification of a glycolipid effector molecule.J. Exp.

Med.201, 535543 (2005).

108. Simeone, R., Bottai, D. & Brosch, R. ESX/type VII

secretion systems and their role in hostpathogen

interaction. Curr. Opin. Microbiol.12, 410 (2009).

109. Schlesinger, L. S. et al. Phagocytosis of

Mycobacterium tuberculosis is mediated by human

monocyte complement receptors and complement

component C3.J. Immunol.144, 27712780 (1990).110. Fratti, R. A. et al. Role of phosphatidylinositol 3-kinase

and Rab5 effectors in phagosomal biogenesis and

mycobacterial phagosome maturation arrest.J. Cell

Biol.154, 631644 (2001).111. Fratti, R. A. et al.Mycobacterium tuberculosis

glycosylated phosphatidylinositol causes phagosome

maturation arrest. Proc. Natl Acad. Sci. USA100,

54375442 (2003).

112. Vergne, I., Chua, J. & Deretic, V. Tuberculosis toxin

blocking phagosome maturation inhibits a novelCa2+/calmodulinPI3K hVPS34 cascade.J. Exp. Med.

198, 653659 (2003).

113. Vergne, I. et al. Mechanism of phagolysosome

biogenesis block by viable Mycobacterium

tuberculosis. Proc. Natl Acad. Sci. USA102, 4033

4038 (2005).

114. Beatty, W. L. et al. Trafficking and release of

mycobacterial lipids from infected macrophages.

Traffic1, 235247 (2000).

115. Malik, Z. A. et al. Cutting edge: Mycobacterium

tuberculosis blocks Ca2+ signaling and phagosome

maturation in human macrophages via specific

inhibition of sphingosine kinase.J. Immunol.170,

28112815 (2003).116. Thompson, C. R. et al. Sphingosine kinase 1 (SK1) is

recruited to nascent phagosomes in human

macrophages: inhibition of SK1 translocation by

Mycobacterium tuberculosis.J. Immunol.174,

35513561 (2005).

117. Randhawa, A. K., Ziltener, H. J. & Stokes, R. W. CD43controls the intracellular growth ofMycobacterium

tuberculosis through the induction of

TNF--mediated apoptosis. Cell. Microbiol.10,

21052117 (2008).

118. Bonecini-Almeida, M. G. et al. Induction ofin vitro

human macrophage anti-Mycobacterium tuberculosis

activity: requirement for IFN- and primed

lymphocytes.J. Immunol.160, 44904499 (1998).119. Gutierrez, M. G. et al. Autophagy is a defense

mechanism inhibiting BCG and Mycobacterium

tuberculosis survival in infected macrophages. Cell

119, 753766 (2004).

This is the first study to show that IFN-treated

macrophages are better able to eradicate

intracellular M. tuberculosis through increased

autophagy.

120. Delgado, M. A. et al. Toll-like receptors control

autophagy. EMBO J.27, 11101121 (2008).

121. Singh, S. B. et al. Human IRGM induces autophagy to

eliminate intracellular mycobacteria. Science313,

14381441 (2006).

122. Fremond, C. M. et al. IL-1 receptor-mediated signal is

an essential component of MyD88-dependent innate

response to Mycobacterium tuberculosis infection.

J. Immunol.179, 11781189 (2007).

123. Master, S. S. et al.Mycobacterium tuberculosis

prevents inflammasome activation. Cell Host Microbe

3, 224232 (2008).

124. Hamon, M., Bierne, H. & Cossart, P. Listeria

monocytogenes: a multifaceted model. Nature Rev.Microbiol.4, 423434 (2006).

125. Gaillard, J. L. et al. Entry ofL. monocytogenes into

cells is mediated by internalin, a repeat protein

reminiscent of surface antigens from Gram-positive

cocci. Cell65, 11271141 (1991).

126. Dramsi, S. et al. Entry ofListeria monocytogenes into

hepatocytes requires expression of InIB, a surface

protein of the internalin multigene family. Mol.

Microbiol.16, 251261 (1995).

127. Mengaud, J. et al. E-cadherin is the receptor for

internalin, a surface protein required for entry of

L. monocytogenes into epithelial cells. Cell84,

923932 (1996).

128. Shen, Y. et al. InIB-dependent internalization of

Listeria is mediated by the Met receptor tyrosine

kinase. Cell103, 501510 (2000).

129. Braun, L., Ghebrehiwet, B. & Cossart, P. gC1q-R/p32,

a C1q-binding protein, is a receptor for the InlB

invasion protein ofListeria monocytogenes. EMBO J.

19, 14581466 (2000).

130. Dunne, D. W. et al. The type I macrophage scavenger

receptor binds to Gram-positive bacteria and

recognizes lipoteichoic acid. Proc. Natl Acad. Sci. USA

91, 18631867 (1994).

131.Alvarez-Dominguez, C., Carrasco-Marin, E. & Leyva-

Cobian, F. Role of complement component C1q in

phagocytosis ofListeria monocytogenes by murine

macrophage-like cell lines. Infect. Immun.61,

36643672 (1993).

132. Drevets, D. A. & Campbell, P. A. Roles of complement

and complement receptor type 3 in phagocytosis of

Listeria monocytogenes by inflammatory mouse

peritoneal macrophages. Infect. Immun.59,

26452652 (1991).

133. Beauregard, K. E. et al. pH-dependent perforation of

macrophage phagosomes by listeriolysin O from

Listeria monocytogenes.J. Exp. Med.186,

11591163 (1997).134. Singh, R., Jamieson, A. & Cresswell, P. GILT is a critical

host factor for Listeria monocytogenes infection.

Nature455, 12441247 (2008).This investigation shows that a host phagosome-

specific protein is required for activation of the

listeriolysin toxin and highlights the level to which

L. monocytogenes has adapted to its host.135. Henry, R. et al. Cytolysin-dependent delay of vacuole

maturation in macrophages infected with Listeria

monocytogenes. Cell. Microbiol.8, 107119 (2006).

136. Shaughnessy, L. M. et al. Membrane perforations

inhibit lysosome fusion by altering pH and calcium in

Listeria monocytogenes vacuoles. Cell. Microbiol.8,

781792 (2006).

This manuscript reports howL. monocytogenes

rapidly induces a delay in phagosome maturation.

137. Smith, G. A. et al. The two distinct phospholipases C of

Listeria monocytogenes have overlapping roles in

escape from a vacuole and cell-to-cell spread. Infect.

Immun.63, 42314237 (1995).

138. Tilney, L. G. & Portnoy, D. A. Actin filaments and the

growth, movement, and spread of the intracellular

bacterial parasite, Listeria monocytogenes.J. CellBiol.109, 15971608 (1989).

139. Eylert, E. et al. Carbon metabolism ofListeria

monocytogenes growing inside macrophages. Mol.

Microbiol.69, 10081017 (2008).

140. Lambrechts, A. et al.Listeria comet tails: the actin-

based motility machinery at work. Trends Cell Biol.18,

220227 (2008).

141. Portnoy, D. A., Auerbuch, V. & Glomski, I. J. The cel l

biology ofListeria monocytogenes infection: the

intersection of bacterial pathogenesis and cell-

mediated immunity.J. Cell Biol.158, 409414

(2002).142. Birmingham, C. L. et al. Listeriolysin O allows Listeria

monocytogenes replication in macrophage vacuoles.

Nature451, 350354 (2008).

This study revealed a novel intracellular fate forL. monocytogenes that was previously

unappreciated.

R E V I E W S





12/12

143. Borella, P. et al. Water ecology ofLegionella and

protozoan: environmental and public health

perspectives. Biotechnol. Annu. Rev.11, 355380

(2005).

144. Brggemann, H., Cazalet, C. & Buchrieser, C.

Adaptation ofLegionella pneumophila to the host

environment: role of protein secretion, effectors and

eukaryotic-like proteins. Curr. Opin. Microbiol.9,

8694 (2006).145. Bellinger-Kawahara, C. & Horwitz, M. A. Complement

component C3 fixes selectively to the major outer

membrane protein (MOMP) ofLegionella pneumophilaand mediates phagocytosis of liposomeMOMP

complexes by human monocytes.J. Exp. Med.172,

12011210 (1990).

146. Payne, N. R. & Horwitz, M. A. Phagocytosis of

Legionella pneumophila is mediated by human

monocyte complement receptors.J. Exp. Med.166,

13771389 (1987).147. Clemens, D. L., Lee, B. Y. & Horwitz, M. A. Deviant

expression of Rab5 on phagosomes containing the

intracellular pathogens Mycobacterium tuberculosis

and Legionella pneumophila is associated with altered

phagosomal fate. Infect. Immun.68, 26712684

(2000).

148. Joshi, A. D., Sturgill-Koszycki, S. & Swanson, M. S.

Evidence that Dot-dependent and -independent

factors isolate the Legionella pneumophila

phagosome from the endocytic network in mouse

macrophages. Cell. Microbiol.3, 99114

(2001).

149. Robinson, C. G. & Roy, C. R. Attachment and fusion of

endoplasmic reticulum with vacuoles containing

Legionella pneumophila. Cell. Microbiol.8, 793805

(2006).

150. Murata, T. et al. The Legionella pneumophila effector

protein DrrA is a Rab1 guanine nucleotide-exchange

factor. Nature Cell Biol.8, 971977 (2006).

151. Machner, M. P. & Isberg, R. R. Targeting of host Rab

GTPase function by the intravacuolar pathogen

Legionella pneumophila. Dev. Cell11, 4756

(2006).

152. Brombacher, E. et al. Rab1 guanine nucleotide

exchange factor SidM is a major phosphatidylinositol

4-phosphate-binding effector protein ofLegionella

pneumophila.J. Biol. Chem.284, 48464856

(2009).153. Ingmundson, A. et al.Legionella pneumophila

proteins that regulate Rab1 membrane cycling.

Nature450, 365369 (2007).154. Machner, M. P. & Isberg, R. R. A bifunctional bacterial

protein links GDI displacement to Rab1 activation.

Science318, 974977 (2007).

155. Nagai, H. et al. A bacterial guanine nucleotide

exchange factor activates ARF on Legionella

phagosomes. Science295, 679682 (2002).

This is the first study to show that an

IcmDot-secreted factor fromL. pneumophila

targets host vesicle trafficking.156. Pan, X. et al. Ankyrin repeat proteins comprise a

diverse family of bacterial type IV effectors. Science

320, 16511654 (2008).

The authors show that C. burnetiisecretes

effectors into host cells.

157. Sauer, J. et al. Specificity ofLegionella pneumophilaand Coxiella burnetiivacuoles and versatility of

Legionella pneumophila revealed by coinfection.

Infect. Immun.73, 44944504 (2005).

158. Sturgill-Koszycki, S. & Swanson, M. S. Legionella

pneumophila replication vacuoles mature into

acidic, endocytic organelles.J. Exp. Med.192,

12611272 (2000).

159. Wieland, H., Goetz , F. & Neumeister, B. Phagosomal

acidification is not a prerequisite for intracellular

multiplication ofLegionella pneumophila in human

monocytes.J. Infect. Dis.189, 16101614 (2004).160. Swanson, M. S., Fernandez-Moreira, E. &

Fernandez-Moreia, E. A microbial strategy to

multiply in macrophages: the pregnant pause.

Traffic3, 170177 (2002).

161.Amer, A. O. & Swanson, M. S. Autophagy is an

immediate macrophage response to Legionella

pneumophila. Cell. Microbiol.7, 765778

(2005).

162. Isberg, R. R., OConnor, T. J. & Heidtman, M. The

Legionella pneumophila replication vacuole: making

a cosy niche inside host cells. Nature Rev. Microbiol.

7, 1324 (2009).

163.Albert-Weissenberger, C., Cazalet, C. & Buchrieser,

C. Legionella pneumophila a human pathogen

that co-evolved with fresh water protozoa. Cell. Mol.

Life Sci.64, 432448 (2007).

164.Voth, D. E. & Heinzen, R. A. Lounging in a l ysosome:

the intracellular lifestyle ofCoxiella burnetii. Cell.

Microbiol.9, 829840 (2007).

165. Heinzen, R. A. et al. Differential interaction with

endocytic and exocytic pathways distinguish

parasitophorous vacuoles ofCoxiella burnetiiand

Chlamydia trachomatis. Infect. Immun.64, 796

809 (1996).166. Capo, C. et al. Subversion of monocyte functions by

Coxiella burnetii: impairment of the cross-talk

between v

3integrin and CR3.J. Immunol.163,

60786085 (1999).

167. Meconi, S. et al. Activation of protein tyrosine kinases

by Coxiella burnetii: role in actin cytoskeleton

reorganization and bacterial phagocytosis. Infect.

Immun.69, 25202526 (2001).168. Meconi, S. et al.Coxiella burnetiiinduces

reorganization of the ac tin cytoskeleton in human

monocytes. Infect. Immun.66, 55275533

(1998).

169. Bern, W. et al.Coxiella burnetiilocalizes in a Rab7-

labeled compartment with autophagic characteristics.

Infect. Immun.70, 58165821 (2002).170. Gutierrez, M. G. et al. Autophagy induction favours the

generation and maturation of the Coxiella-replicative

vacuoles. Cell. Microbiol.7, 981993 (2005).171. Romano, P. S. et al. The autophagic pathway is actively

modulated by phase II Coxiella burnetiito efficiently

replicate in the host cell. Cell. Microbiol.9, 891909

(2007).172. Maurin, M. et al. Phagolysosomes ofCoxiella burnetii-

infected cell lines maintain an acidic pH during persistent

infection. Infect. Immun.60, 50135016 (1992).173. Hackstadt, T. & Williams, J. C. Biochemical stratagem

for obligate parasitism of eukaryotic cells by Coxiella

burnetii. Proc. Natl Acad. Sci. USA78, 32403244

(1981).

174. Mertens, K. et al. Constitutive SOS expression and

damage-inducible AddAB-mediated recombinational

repair systems for Coxiella burnetiias potential

adaptations for survival within macrophages. Mol.

Microbiol.69, 14111426 (2008).

AcknowledgementsWork in the authors laboratory is supported by the Canadian

Cystic Fibrosis Foundation, the Heart and Stroke Foundation

of Ontario and the Canadian Institutes of Health Research

(CIHR). R.S.F. is supported by a CIHR Fellowship and G.C. is

supported by the National Council of Science and Technology

of Mexico (CONACYT).

DATABASESErez Gee Prje:http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=genomeprj

Coxiella burnetii | Legionella pneumophila |Listeria

monocytogenes| Mycobacterium tuberculosis

uiPrKb:http://www.uniprot.org

ActA|ARF6|ARNO|Cdc42|CYBA| DIAPH1|DrrA | EEA1 |

EHD1|GAPVD1|IFN| IL-1 | InlA| InlB | LAMP1 | LepB |LidA|NCF1|NCF2 | NCF4 |NOS2 | NOX2 | NRAMP1 | PIP5K3|

Rac1 |Rac2|Rab5A|Rab7A|Rab11A|RalF|RILP | SNX1|

SNX2 | SNX4|SYK | VAMP3|VAMP7 | VAMP8|VPS4A |

VPS26A | VPS29 | VPS35

All linkS ArE AcTivE in ThE onlinE Pdf

R E V I E W S

366 | MAY 2009 | vOuME 7 / /

R E V I E W S
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=genomeprjhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=genomeprjhttp://www.ncbi.nlm.nih.gov/sites/entrez?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=16724http://www.ncbi.nlm.nih.gov/sites/entrez?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=13147http://www.ncbi.nlm.nih.gov/sites/entrez?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=12309http://www.ncbi.nlm.nih.gov/sites/entrez?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=12309http://www.ncbi.nlm.nih.gov/sites/entrez?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=12309http://www.ncbi.nlm.nih.gov/sites/entrez?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=12318http://www.uniprot.org/http://www.uniprot.org/http://www.uniprot.org/uniprot/P33379http://www.uniprot.org/uniprot/P33379http://www.nature.com/nrmicro/index.htmlhttp://www.nature.com/nrmicro/index.htmlhttp://www.nature.com/nrmicro/index.htmlhttp://www.nature.com/nrmicro/index.htmlhttp://www.nature.com/nrmicro/index.htmlhttp://www.nature.com/nrmicro/index.htmlhttp://www.uniprot.org/uniprot/P60953http://www.uniprot.org/uniprot/P60953http://www.uniprot.org/uniprot/P60953http://www.uniprot.org/uniprot/P13498http://www.uniprot.org/uniprot/P13498http://www.uniprot.org/uniprot/P13498http://www.uniprot.org/uniprot/A0RZB8http://www.uniprot.org/uniprot/A0RZB8http://www.uniprot.org/uniprot/Q29ST3http://www.uniprot.org/uniprot/Q29ST3http://www.uniprot.org/uniprot/Q15075http://www.uniprot.org/uniprot/Q9H4M9http://www.uniprot.org/uniprot/Q9H4M9http://www.uniprot.org/uniprot/Q14C86http://ww

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