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83 Cards in this Set
- Front
- Back
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What directs migration of dendritic cells from the peripheral tissues into the lymphoid tissues
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CCR7
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What are the three antigen presenting cells found in the lymph nodes
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Macrophages
Dendritic cells B cells |
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What makes APC's good at stimulating naive T cells
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They express high levels of MHC and co-stimulatory molecules
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T cells enter the lymph nodes primarily through
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HEV
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What are two ways that naive T cells can enter the lymph nodes
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Through high endothelial venules or afferent lymphatics
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L-selectin is important in what process
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Initiates rolling of naive t cells along the HEV where the cells will eventually cross into the lymph nodes
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Extracellular bacteria binds which class of MHC molecules
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MHC Class II --> which activate CD4 T cells
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Cytoplasmic viruses bind which class of MHC molecules
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MHC Class I --> which activate CD8 T cells
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Where in the body do mature dendritic cells present pathogens to the T cells
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in the lymph nodes
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What molecule increases the affinity or binding between T cells and dendritic cells
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LFA-1
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What retains or traps T cells in the lymph nodes for several days to allow them to become activated
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The tight binding between T cells and dendritic cells in the lymph node caused by LFA-1
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The activation of a T cell requires two things...
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1) antigen
2) co-stimulation |
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If you dont have co-stimulation of a T cell what will happen to it
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It will become adrenergic or unresponsive and will eventually die
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After T cells are activated what do they produce
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IL-2
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What part of the CD3 complex is required for T cell activation
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ITAM's
(immunoreceptor tyrosine-based activation motifs) |
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ITAM phosphorylation leads to activation of
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ZAP-70
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What happens to patients who are deficient in ZAP-70
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They have profound immunodeficiency because their T cells cant respond to antigen therefore can not be activated
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The second messenger DAG activates
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NF-kb and AP-1
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The second messenger IP3 activates
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NF-AT
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Cyclosporin is an immunosuppresant drug that inhibits
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calinurin activation, which prevents NF-AT, which is essential for T cell activation
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What three factors induce IL-2 gene transcription
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NF-kb
AP-1 NF-AT |
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Rapamycin is an immunosuppresant that intereferes with
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the ability of T cells to respond to IL-2
therefore this person would have activated T cells they just would not be able to respond |
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What follows T cell activation
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differentiation
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cytotoxins are
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cytotoxic cytokines
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Is CD45RA highly expressed in resting naive T cells or in activated T cells
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CD45RA is highly expressed in resting T cells
(ie. in newborns there would be a high level) |
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Is CD45RO expressed more in the resting or activated T cell state
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activated effector T cell
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VLA-4 is expressed in
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activated effector T cells
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Which subset of effector T cells is more heterogeneous
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T helper cells (CD4+)
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CD4 Th1 cells activate
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macrophages
to help kill intracellular bacteria |
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Which effector cells activate B cells to produce antibodies
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CD4 Th1 and Th2 cells
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Th2 cells are very good at clearing
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Helminth parasites
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Which effector cell enhances the neutrophil response
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Th17
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Th17 cells are target what kind of pathogen
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extracellular bacteria
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What effector cell has the capability to suppress all the other T-cell responses
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regulatory T cells or Tregs
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Which effector cell type specializes in killing viral infections
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CD8+ cytotoxic T cells
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lytic granules are found in what category of effector cells
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CD8+ cytotoxic T cells
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What cytotoxins are found in lytic granules in CD8 T cells
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Perforin
Granulysin Granzymes |
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What cytotoxin aids in delivering the contents of granules into the cytoplasm of the target cells
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Perforin
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Which cytotoxins are responsible for activating apoptosis once inside the target cell
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Granzymes
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Granzymes enter the target cell through
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polymers in the cell membrane formed by perforin
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Granzyme B activates
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caspases
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Caspases activate
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DNases
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What are 2 pathways by which CTL's kill
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Granule exocytosis mediated cytotoxicity
Receptor-mediated cytotoxicity |
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What is involved in receptor-mediated cytotoxicity
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Fas binds to and trimerizes Fas ligand
recruitment of FADD activation of caspases cell death |
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What are three immune responses of CD4 helper T cells
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Activation of macrophages
Activation of B cells -> antibody production Activation of naive CD8 cells |
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What influences differentiation of effector subsets
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cytokines produced by the antigen presenting cell
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IL-12 and INF-y signal differentiation into
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TH1 cells
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IL4 signals differentiation into
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TH2 cells
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TH1 cells express which transcription factor
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Tbet
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interferon gamma has what effects on macrophages
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1) increased MHC expression
2) increased production of NO and oxygen radicals 3) increased production of antimicrobial peptides and proteases |
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The Th1 effector T cell subset produces
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IFN-y
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What two signals are involved in the activation of macrophages by Th1 cells
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IFN-y and CD40
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Granulomas are associated with which effector subset
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Th1
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Are granulomas good or bad?
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Good because they contain and localize the pathogen
Bad if you fail to develop them |
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DTH (delayed-type hypersensitivity) involves what effector cell
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Th1
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The Th2 effector subset population produces
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IL4, IL5, and IL10
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Tbet is to Th1 as ___ is to Th2
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GATA-3
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Which effector subset population inhibits macrophage activation
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Th2
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Which effector T cells recruit eosinophils and mast cells to sites of infection
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Th2
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Th2 cells activate B cells to undergo class switching via
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CD40
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Immediate hypersensitivity is associated with
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Th2 effector cells
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Antigen specific IgE and mast cells are a part of what condition
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immediate hypersensitivity associated with Th2
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Is a host infected with a pathogen that causes its cells to secrete IL 4, IL5, and IL10 more likely to be resistant or susceptible
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susceptible because it can not form granulomas
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The structure of chemokine receptors
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7 transmembrane G protein couple receptor
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The structure of cytokine receptors
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heterodimeric receptors
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Cytokines initiate pathways of signal transduction though the
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JAK STAT pathway
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IL2, IL7, IL15, and IL4 bind what receptor?
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the common gamma chain receptor
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The common gamma chain cytokines are important for
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lymphocyte survival
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Mutations in the common gamma chain receptor cause
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X-linked severe combined immunodeficiency syndrome (X-SCID)
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IL12, IFN alpa and beta, IFN gamma, and the TNF family are what kind of cytokines
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Pro-inflammatory
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What are the biological effects of IL-12
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Stimulation of IFN-gamma secretion
Differentiation of Th1 cells |
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Patients with IL-12 deficiencies are highly susceptible to
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Salmonella and Mycobacterial infections
(intracellular bacterial infections) |
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Anti-viral immunity is the biologic effect of which cytokine
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IFN alpha/beta
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Which cytokine is responsible for the activation of macrophages
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INF- gamma
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Fas-L and CD40L are a part of
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the TNF family
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Which cell is responsible for T cell apoptosis
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Fas-L
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Which cell can activate macrophages and B cells
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CD40
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ALPS (autoimmune lympho proliferative disorder) is related to what cytokine
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a mutation is Fas, which interferes with the ability to get rid of T cells
extreme swelling if the lymph nodes occurs |
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Mutations in CD40 can lead to
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hyper IgM syndrome
because it interferes with the ability for B cells to undergo isotype switching |
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Anti-inflammatory cytokines include
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TGF-beta
IL-10 |
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Which cytokines are important in inhibiting T cell proliferation
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IL-12 and TGF-beta
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what is considered the first line of host defense against bacteria
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neutrophils
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the immunosuppressive drug that inhibits T cell signalling
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cyclosporin A
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