T cell mediated immunity II Flashcards
After an infection is resolved, __% of CTLs undergo apoptosis.
After an infection is resolved, ~90%% of CTLs undergo apoptosis.
How Th1 cells activate macrophages
IFN-γ production
CD40L
Both promote classical activation
IL‐5
A potent eosinophil growth factor and activator
ILCs vs T cells
ILCs have no antigen receptor, but have analogous effector functions to TH1, 2, and 17.
NK cells are also ILCs, and are the functional equivalents of CTLs.
T cell memory can last for up to ____ years.
T cell memory can last for up to 75 years.
Th1, Th2, Th17, and Tfh
Perforin molecules that diffuse away are inhibited by ___.
Perforin molecules that diffuse away are inhibited by plasma lipids.
Pathogen types and associated TH subsets
Classical vs Alternative macrophage activation
_____ are required for ILC development from a common precursor
IL‐15 or IL‐7 are required for ILC development from a common precursor
CTL granule contents
At peak after EBV, CMV, HIV infection, ____ % of all T cells in the blood may be specific for just one single viral peptide‐ MHC antigen
At peak after EBV, CMV, HIV infection, 25‐ 50 % of all T cells in the blood may be specific for just one single viral peptide‐ MHC antigen
CTL-Target Cell Interaction
Bystander cells (e.g. antigen presenting cells) may be protected from CTL-mediated death by expressing _____
Bystander cells (e.g. antigen presenting cells) may be protected from CTL-mediated death by expressing specific and irreversible granzyme inhibitors (serpins).
Helper T cell Differentiation
TH2 functions
Development of ILCs
Clonal expansion of T cells
The major benefit of CD4 help to CD8 cells is enhanced _____.
The major benefit of CD4 help to CD8 cells is enhanced generation of memory CD8 T cells.
All TH subsets
1, 2, 3, 9, 17, 22, follicular helper, regulatory
IL‐22
Enhances epithelial barrier function by promoting epithelial cell growth (to repair breaches) and reinforcing tight junctions.
Also increases defensin production.
JAK STAT Signaling
Classical Macrophage Activation
“licensing” of the DC
T cell activation by a DC recpirocally activates the costimulatory activity of the DC, as it has been “liscensed” as a dangerous antigen-carrying DC. This makes subsequent CD4 or CD8 T cell activation easier.
IL‐4 and IL‐13
- Mediate class switching to IgE
- Activate eosinophils, mast cells, basophils
- enhance gut peristalsis to expel worms
- induce alternative macrophage activation (IL-10, tissue fibrosis)
- Sensitizes eosinophils and mast cells
_____ may lead to granulomatous inflammation
Chronic TH1 responses may lead to granulomatous inflammation
Particularly when the microbe cannot be killed by the phagocyte or ecsapes into its cytoplasm (eg, Mycobacterium tuberculosis)
Evasion of CTL Surveillence
Immunologically Relevant STATs
CD4/CD8 interaction
Differentiation of naive CD8+ T cells into CTLs
Shared properties of T cells and ILCs
CTLs secrete the major cytokines ____ and ____.
CTLs secrete the major cytokines TNF-αandIFN-γ.
The role of ILCs vs that of T cells
- ILCs are innate early responders, already present and ready to respond before prior antigen exposure
- ILCs do not have clonally distributed antigen receptors and thus are not highly antigen specific
- ILCs do not contribute to memory responses
Life of a CD8+ T Cell
TH17 functions
Eosinophils are circulating granulocytes that are not ____ like neutrophils, but instead ____.
Eosinophils are circulating granulocytes that are not phagocytic like neutrophils, but instead release proteolytic granule contents.
