immune response: initial infection
DESCRIPTION
Antigens (proteins that can be recognized by antibodies). Immune Response: Initial Infection. Pathogens (disease-causing bacteria or viruses or other organisms) invade your body. Macrophage. B Cell# 34,599. B Cell # 146,883. Cell-Mediated Response. Antibody-Mediated Response. - PowerPoint PPT PresentationTRANSCRIPT
Immune Response: Initial Infection
Pathogens (disease-causing bacteria or viruses or other organisms) invade your body
Antigens (proteins that can be recognized by antibodies)
Immune Response Step 1: Initial Recognition of Infection
Cell-Mediated Response Antibody-Mediated Response
Macrophage
B Cell # 146,883
B Cell# 34,599
MACROPHAGE are white blood cells that gobble up foreign invaders.
MHC Protein
B CELLS are white blood cells that produce antibodies. Each person can produce hundreds of millions of different B
Cells. Each type of B cell is genetically-unique and produces a unique antibody. Two B cells(out of hundreds of
millions) are shown here.
ANTIBODIES are Y-Shaped proteins. The ends of the arms of the Y have antigen-binding sites. Each different
type of antibody has a uniquely shaped antigen-binding site.
Immune Response Step 2: Phagocytosis of Pathogen
Cell-Mediated Response Antibody-Mediated Response
Macrophage
MACROPHAGE engulf (phagocytize) the pathogenic invader. After this, the macrophage kills
and breaks down the pathogen into pieces.
The B CELL that has an antibody that binds to antigen engulfs(phagocytizes) the antigen-antibody complex. After this, the B cell kills and
breaks down the pathogen into pieces.
B Cell # 146,883
Immune Response Step 3: Antigen-Presenting Cells
Cell-Mediated Response Antibody-Mediated Response
Antigen-Presenting
CellAntigen-Presenting
Cell
MACROPHAGE display parts of the pathogen alongside the MHC protein. At this point, the
macrophage is called an Antigen-Presenting Cell (or APC).
The B CELLdisplays parts of the pathogen alongside the MHC protein. At this point, this B cell is called an Antigen-
Presenting Cell (or APC).
Immune Response Step 4: Helper T Cell-APC Interaction
Cell-Mediated Response Antibody-Mediated Response
Antigen-Presenting
CellAntigen-Presenting
Cell
T Cell # 2,888,124
T Cell #492
HELPER T CELLS are another kind of white blood cell. There are hundreds of millions of different kinds of T Cells. Each is genetically
unique and each displays a unique form of the protein called T Cell Receptor protein. Shown
here are two of the hundreds of millions of different kinds of T Cells in a persons body.
Immune Response Step 5: Helper T Cell Stimulation
Cell-Mediated Response Antibody-Mediated Response
Antigen-Presenting
CellAntigen-Presenting
Cell
T Cell # 2,888,124
Binding of Helper T Cell to APC stimulates the APC to secrete Interleukin. Interleukin stimulates Helper T cells to rapidly reproduce. Since Helper
T Cell # 2,888,124 is locked on, it will be in an area of high Interleukin concentration. So among
all the Helper T Cells floating around the body, Helper T Cell # 2,888,124 will be the one to
reproduce rapidly and repeatedly.
Immune Response Step 5: Helper T Cell Proliferation
Cell-Mediated Response Antibody-Mediated Response
Antigen-Presenting
CellAntigen-Presenting
Cell
T Cell # 2,888,124
Huge numbers of T Cell # 2,888,124 are produced.
T Cell # 2,888,124
T Cell # 2,888,124T Cell # 2,888,124
T Cell # 2,888,124
T Cell # 2,888,124
T Cell # 2,888,124 T Cell # 2,888,124
Immune Response Step 6: Helper T Cell DifferentiationCell-Mediated Response Antibody-Mediated Response
Antigen-Presenting
CellAntigen-Presenting
Cell
T Cell # 2,888,124
Cytotoxic T Cells kill body cells infected by the pathogen.
MEMORY T Cell # 2,888,124
CYTOTOXIC T Cell # 2,888,124
HELPERT Cell # 2,888,124
CYTOTOXIC T Cell # 2,888,124CYTOTOXIC T Cell # 2,888,124
CYTOTOXIC T Cell # 2,888,124CYTOTOXIC T Cell # 2,888,124
MEMORY T Cell # 2,888,124
MEMORY T Cell # 2,888,124MEMORY T Cell #
2,888,124MEMORY T Cell #
2,888,124
MEMORY T Cell # 2,888,124 HELPERT Cell #
2,888,124HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
Memory T Cells are fairly inactive. They reproduce at a steady pace.
Helper T Cells interact with other white blood cells to propagate the immune response.
Immune Response Step 7: Helper B Cell StimulationCell-Mediated Response Antibody-Mediated Response
Antigen-Presenting
CellAntigen-Presenting
Cell
T Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HE
LP
ER
T C
ell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPER T CELL #2,888,124 binds to the antigen-presenting B cell (#146,883)
since this B cell displays the same antigen-MHC complex. This binding stimulates Helper T Cell to secrete
Cytokines. Cytokines stimulate B cells to rapidly reproduce. Since B cell
146,883 is locked on, it will be the one to rapidly reproduce. Thus, the B Cell
that produces the antibody that binds to the current infectious agent is the one
that proliferates.
Immune Response Step 8: Helper B Cell ProliferationCell-Mediated Response Antibody-Mediated Response
Antigen-Presenting
CellAntigen-Presenting
Cell
T Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HE
LP
ER
T C
ell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
Many copies of B Cell 146,883 are produced.
B Cell # 146,883
B Cell # 146,883B Cell # 146,883
B Cell # 146,883
B Cell # 146,883
B Cell # 146,883
B Cell # 146,883
B Cell # 146,883B Cell # 146,883
Immune Response Step 9: Helper B Cell DifferentiationCell-Mediated Response Antibody-Mediated Response
Antigen-PresentingCell
HE
LP
ER
T C
ell # 2,888,124
Plasma B Cells produce and secrete large quantities of antibodies. This helps to fight the current infection.
Memory B Cell # 146,883
Plasma B Cell#146,883
Plasma B Cell#146,883
Plasma B Cell#146,883
Plasma B Cell#146,883
Plasma B Cell#146,883
Plasma B Cell#146,883
Memory B Cell # 146,883
Memory B Cell # 146,883
Memory B Cell # 146,883
Memory B Cell # 146,883
Memory B Cell # 146,883
Memory B Cells are fairly inactive. They reproduce at a steady rate and will be present if the body is ever re-infected
with the same pathogen.
Immune Response Step 10: Immunity
Memory B Cell # 146,883Memory B Cell
# 146,883
Memory B Cell # 146,883
Memory B Cell # 146,883
Memory B Cell # 146,883
Memory B Cell # 146,883
If the body is ever again infected with the same pathogen, then the particular Memory T Cells and Memory B Cells that specifically recognize and bind this pathogen are already present. So steps 1-5 and 7-8 won’t have to happen. This makes for a faster immune response upon
re-infection (so you don’t feel like you’re sick).
MEMORY T Cell # 2,888,124MEMORY T Cell #
2,888,124
MEMORY T Cell # 2,888,124MEMORY T Cell #
2,888,124MEMORY T Cell #
2,888,124
MEMORY T Cell # 2,888,124
MEMORY T Cell # 2,888,124
MEMORY T Cell # 2,888,124
MEMORY T Cell # 2,888,124
Human Immunodeficiency VirusCell-Mediated Response Antibody-Mediated Response
Antigen-Presenting
CellAntigen-Presenting
Cell
T Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HE
LP
ER
T C
ell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HELPERT Cell # 2,888,124
HIV infects Helper T Cells. When HIV infects a person’s body, that stimulates an immune response. This causes an
increase in Helper T Cells. But this increase in Helper T Cells is an
increase in hosts as far as HIV is concerned.