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19 Cards in this Set
- Front
- Back
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What are 3 effects CD4 cells can have on other leukocytes?
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1) act as T helpers for B cells
2) activate CMI (CD8, NK, macrophages) 3) activate effector cells of innate immunity (neutrophils & eosinophils) |
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____ from DC signals to make TH1 cells. These secrete ____ & ____ which act on what? This does what?
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- IL-12
- INF gamma & IL-2 - act on macrophages, NK cells, CD8 - when these cells are activated they are effectors of CMI - remove affected cells from the body |
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In response to allergens & worms: _____ secreted signals to make TH2 cells. These secrete ____, ____ & ____. ___ & ____ signal to have B cells make IgE & IgG4, whereas _____ signals to make eosinophils.
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- IL-4
- IL-4, 13, 5 - IL- 4 & IL-13 - IL-5 |
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TH17 cells produce ___ & _____. what does this activate? Who is it responding to?
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- IL-17, IL-22
- pro-inflammatory: activates neutrophils & epithelial cells at mucosa - responding to fungi & extracellular bacteria |
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which subset of CD4 T cells is commonly implicated in auto-inflammatory conditions (such as psoriasis & rheumatoid arthritis & MS)
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- TH17
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IL-2 & INF gamma made by _____ T cells inhibit _____. IL-4, 5, 13 made by _____ T cells inhibit ____. This is said to be _____ the response
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- TH1
- TH2 & TH17 - TH2 - TH1 & TH17 - skweing |
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nearly all proteins are __________ antigens meaning they require help from CD4 helper cells for B cells to synthesize antibody
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- thymus-dependent antigens
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what 2 things must be necessary for Th-B cooperation?
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1) they must be specific for same antigen
2) recognize parts of a single structure (linked recognition) |
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Th-B interaction occurs predominantly in the _________. Th is required for what 2 things?
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- germinal center
1) formation of germinal center 2) generation of long-lived antibody responses after infection or vaccination |
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after the mutual activation of Th & B cells, Th synthesizes _____ & B cells synthesize _________. Activation requires what two signals?
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- cytokines
- antibody 1) 1st signal = peptide in MHC II <--> TCR 2) costimulator pairs = B7 <--> CD28 & CD40 <--> CD40L |
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IL-4 causes CSR to ____ & _____. INFgamma causes CSR to ____.
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- IgE & IgG4 - allergy, parasites
- IgG3 - complement activation |
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Which costimulator pair is essential for CSR? What happens if you don't have CD40 L (CD154)? CD40 & AID defects can also causes problems in CSR.
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- CD40 + CD40 L
- X-linked hyper-IgM syndrome |
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_______ do NOT require T cell help for B cells to synthesize antibody (such as strep pneumonia & influenzae). Which Ig molecule predominates in this response? Is there memory? How do you induce vaccines?
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- thymus independent antigens
- IgM predominates b/c no CSR - no memory b/c no CSR - try to induce vaccine using conjugate (linking them to proteins) |
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CD8 cells must be activated before they kill the virus-infected or tumor cell. How are they activated?
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- requires 1st & 2nd signals from APC (usually dendritic cells & cytokines)
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Most viruses (eg HIV) need _____ T cells to activate _____ T cells. Some viruses do not.
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- CD4+
- CD8+ |
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How does a CD8 cell kill the target cell?
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- CD8 interacts with MHC1
- granules move towards edge of T cell near target cell & release perforin which polymerized in membrane & granzymes that enter target cell & induce apoptosis - also FAS on target cell & FAS L on T cell |
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at the end of the immune response who dies? who survives?
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- death of majority of activated cells
- survival of memory T & B cells (memory cells make fast effective response after re-exposure to antigen) |
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What signal on the T cell helps to turn off the response?
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- CTLA-4 on T cell competes with CD28 for B7 binding on APC
- this causes inhibition of the T cell response |
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Treg cells secrete ____ & ______ which inhibit or suppress the differentiation & function of other subsets of CD4 T cells
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- IL-10 & TGF beta
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