Ch 11: Differentiation and Functions of CD8+ T Cells Flashcards
Role of CD4+ T Cells in Activation of CTLs (3)
1) Dendritic cell with co-stimulation and cytokines without helper T cells
2) Dendritic cells bind CD4+ helper cells with costimulators (CD40L and CD40) and cause the dendritic cell to express B7 thus enhancing interaction with CD8+ T Cells
3) CD4+ helper T cells activated by APC produce cytokines that stimulate CTL differentiation
The molecular events in CTL differentiation involve txn factor ___ which regulates the txn of genes encoding ___, ___, and ___
T-bet
perforin, granzymes, and IFN-y
CD4+ helper T cells are required for CD8+ T cell responses when relatively ___ ___ immune reactions are evoked by what?
weak innate
latent viral infections, organ transplants, and tumors
Evidence suggests that CD4+ helper T cells are more important for the generation of ______ than for differentiation of naive _____ into ___ CTLs
CD8+ memory T cells CD8+ T cells into effector CTLs
alpha subunit of IL-2R shares a common receptor component with __ and __
IL-15 and IL-21
What stimulates the differentiation of naive CD8+ T cells into effector CTLs?
IL-12 and type 1 IFN. Naive CD8 T cells proliferate in response to TCR and CD28 signals but require IL-12 or type 1 IFN for survival and development of optimal effector fnct
DCs and macrophages may produce IL-? which is important for the survival of memory CD8+ T cells
IL-15
Activated CD4+ T cells produce IL-21 which does what?
Induces CD8+ T cell memory and prevents its exhaustion
IL-2 shares a common receptor component (y chain) with what other cytokines?
4,7,9,15,21
IL-12
assists in prevention of CD8+ T cells exhaustion
activates NK cells
contolls tumors
promotes production of IFN-y and TNF-B
Primary source of IL-15 is?
activated tissue macrophages and mature DCs
IFN-y has the ability to increase ___ molecule on a range of cells and induce expression of ___ molecules on professonial APCs
MHC class I MHC class II
Activated CTLs secrete pro-inflammatory __, ___ and cytoxic __ and __
TNF-B, IFN-y and perforin and granzymes
T cell exhaustion has reduced production of what and increased expression of what
decreased IFN-y and increased PD-1 inhibitory receptor and CTLA-4
Which granzyme is the only one required for CTL cytotoxicity
B not A or C
