Lecture 12 - Helper T cells and their response to antigen Flashcards
Structure of TCR
a and B chain form antigen binding groove, there are 2 extracellular domains, a transmembrnae domain, and a cytoplasmic domain
How to tell if TCR complex is Th or T cytotoxic
TH binds with CD4 and T cytotoxic has CD8
How does T cell-APC interaction result in activation
TCR-MHCII binding activates CD 154, activates, CD28, increases IL-2
How does T cell-APC interaction result in inactivation
- CD154 binds to CD40, Activates CD80/86 (prev. bound to CD28) and it binds to CD152 which inactivates.
- IDO destroys tryptophan, terminates T cell response
What is the role of costimulation in T cell activation
increased expression of costimulators activate APCs and result in T cell proliferation and differentiation
CD4+ aB T cells are called
T helper cells
CD4+ aB T cells recognize antigens displayed on
MHC II
Naive Th cells differentiate into
TH1, TH2, TH17, and T reg
What dictates what naive T helper cells will differentiate into
signals naive TH cells receive from APCs and the local environment
What is the most important signal for differentiation of naive CD4+ T cells and what is it determined by
cytokines produced by; determined by nature of infection
Each effector T cell subset produces cytokines that …
amplify itself and inhibit the other subsets
Differentiation of each subset is associated with the _____
activation of TF that stimulate production of various cytokines
What cytokines help stimulate production of TH1
IL-12, IFN-y
What cytokines help produce TH2 cells
IL-4
What infection stimulates production of TH1 cells
intracellular microbes
What infection stimulates production of TH2 cells
helminths
What infection stimulates the production of TH17 cells
extracellular fungi, bacteria
Th-polarizing cytokines for Th1
IL-12, IFN-y
Th-polarizing cytokines for Th2
IL-4, IL-33, TSLP
Th-polarizing cytokines for TH17
IL-6, IL-23, TGFB
Th-polarizing cytokines for Treg
IL-10, TGF-B
TF for Th1
T-bet
TF for Th2
GATA3
TF for Th17
ROR-yt