MICROBIOLOGY – ALCAMO

LECTURE:

Specific Immune SystemB Cells

&

T Cells

Specific Immune System

• Late 1800’s:– not sure how body responded to ________– knew there were certain ________ in blood

involved (Bence Jones proteins)• 1922:– these ________ were unlike other serum

________

Specific Immune System• 1950’s:– post-war explosion in biological research– realized that ________ ________ applied to

disease, organ transplant, allergies, resistance to cancer

• 1960’s:– structure of ________ ________– maturing of ________ as a key scientific discipline

Specific Immune System• Last ________ mechanism of the body

– failure to beat the invader means death

• “Man to Man” defense against ________• Specific immune system cells:

– Only ________ – type of WBC

Antigens• Substances capable of mobilizing the

________ ________ and provoking immune responses

• Large ________ ________ not normally present in the body

• They are anything ________ : Mo’s, Cells, Cells containing MO’s, or chemicals

• ________ – small area of antigen that stimulates the immune response

Antigens• Exhibit 2 important properties:– _______________– ability to stimulate the

proliferation of the immune system cells– ________ – ability to react with the products of

the immune system cells or the immune system cells themselves

Antigens

• ________ ________ ________– before birth, the proteins and polysaccharides of the body contact and inactivate immune system cells

• These substances are now seen as “________” and will be tolerated by immune system

Origins of Immune System

• General term for a complex series of cells, factors, and processes that provide a ________ ________ to antigens

• ______________ – the cornerstone of the immune system:– Spread throughout the body– Small cells (10-20 um) with a large nucleus– Can be ____________ or ____________

Origins of Immune System

• Immune system arises in a ________ ~ 2 months after conception

• Lymphocytes arise from precursor cells in the bone marrow (________ ________)

• Stem cells can be:– ______________ – become RBC’s– ______________ – become WBC’s

T LymphocytesOriginal cells from ________ ________• Memory programmed in ________ ________• Circulate in blood, colonize lymph tissue• Interact directly with ________ marked cells and

destroy them• ________ : Infected body cells, fungi, protozoa, cancer, transplants

T Lymphocytes2 “T” cell types (total 4 “T” Cells)

– ________ ________ ________ :• ________ T - worker• Delayed Sensitivity T - allergies

– ________ ________ ________ :• ________ – don’t kill• ___________ – lower immune response

• Active chemical: Lymphokines ( a group of glycoproteins)

T LymphocytesProcess• ________ ________ finds antigen in tissue (cell’s

surface looks different if infected)• Brings it to lymph tissue containing ________

________(spleen or lymph node)• May remember ________• If “Yes”• If “No”• Cell ________ Immunity (CMI)

T LymphocytesIf “Yes”• ________ 2 Cell Types• ________ ________ and• ________ ________ which makes

lymphokines• Lymphokines kill or inactivate ________

and ________ phagocytosis

Back

T Lymphocytes

If “NO”• In ________, program

________ T cells for antigen memory

• To ________ tissue in nearest war zone

• Now: ________ ________ T and Killer T Back

B LymphocytesProfile• Original cells from ________ ________• Memory programmed in bone marrow• Circulate in blood and

colonize ________ ________• ________ : Bacteria,

Viruses, Chemicals• Active chemical:

________

B Lymphocytes

Process• ________ cell finds antigen in blood• Brings it to lymph tissue containing ________

________ ________• May remember ________ from before

– We all have 1,000s of memory B cells

• If “YES”• IF “NO”

B Lymphocytes• If “Yes”:

– ________ 2 cell types– ________ ________ ll (so it won’t

forget) and plasma cell to make ________ (2,000 molecules/sec/cell 4-5 days)

– Antibodies kill or inactivate ________ and stimulate ______________

Back

B Lymphocytes• If “No”:

– ________ ________ ________ in bone marrow program for antigen memory to lymph tissue nearest “war zone”

– Now clone ________ and ________ cells

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B LymphocytesProcess (continued)• ________ : Stimulate complement proteins to

attack• ________ and ________ clean up• Antibody Mediated Immunity (AMI)

Antibodies• Edelman and Porter described the structure of

antibodies (1972)• Basic ________ Protein:• Has 4 ________ chains– 2 identical heavy chains (400 AA)– 2 identical light chains (200 AA)– Joined together by disulfide bonds to form a “___”

________ ________• Is called a ________ and has 2 identical halves

(1 heavy and 1 light chain each)

Antibodies

• Have ________ and ________ regions• Constant regions – ________ in all antibodies

(AB)• Variable regions – ________among 100’s of

thousands of different AB– Form a very specific, ________ ________– Uniquely shaped to “fit” a ________ ________– Each arm can bind an ________

Types of antibodies

• Five Types – based on differences in heavy chain:– 1. ________ – five monomers joined to form a

pentamer, First AB to appear after stimulation of ________

– 2. ________– monomer, the major AB in the blood that appears ________ ________ antigen appears, provides ________ ________ resistance, crosses placenta to give immunity to ________

Types of antibodies• Five Types – based on differences in heavy

chain:– 3. ________ – dimer shaped AB that accumulates

in ________ ________ in respiratory and GI tracts, in tears and saliva, and in the 1st milk secreted by a ________ ________

– 4. ________ – monomer that is involved in ________ reactions

– 5. ________– monomer – function unknown

Antigen antibody Interaction

• Neutralizing AB’s – react with viral capsids and ________ entry into cells

• Antitoxins – ________ toxin molecules released by antigen

• Agglutinins – ________ ________ of antigens and enhances phagocytosis

• Precipitins – ________with dissolved antigens and ________ them to solids