T cells- Block 2 Flashcards
what are the 5 steps involved in the MHC class I pathway
- antigen engulfed
- antigen goes to proteasome to be cleaved
- cleaved peptide is transported to ER by TAP
- peptide is loaded on MHC
- MHC with peptide brought to cell surface for CD8+ T cell recognition
what are the 5 steps involved in the MHC class II pathway
- antigen engulfed
- antigen contained in vesicle
- vesicle acidified, antigen cleaved
- antigen loaded on MHC molecule
- MHC with antigen brought to cell surface for CD4+ T cell recognition
what is involved in the binding step of T cell activation
receptor on T cell surface binds to MHC class II complex on antigen presenting cell surface
during T cell co-stimulation, what molecule is present on the T cell
CD28
during T cell co-stimulation, what molecule is present on the antigen presenting cell
CD80/86 or B7.1/7.2
if the antigen encountered is an intracellular pathogen, what cytokine is released by the antigen presenting cell
IL-12
what does the naive T cell become with release of IL-12
Th1
what Th cell expresses CD40L
Th1
what cytokines are released by Th1 cells
IFN gamma
TNF alpha
IL-2
what is the effect of IFN gamma and IL-12 release from Th1 cells
increase in macrophage activity and CD8+ cell activity
if the antigen encountered is a helminth (worm)/parasite, what cytokine is released by the antigen presenting cell
IL-4
What does the naive T cell become with release of IL-4
Th2
what cytokines do Th2 cells release
IL-4
IL-5
IL-13
what is the effect of release of IL-4, IL-5, and IL-13 by Th2 cells
4- antibody production and mast cell degranulation
5- eosinophil activation
13- increased macrophage activity
if the antigen encountered is an extracellular pathogen (fungi/bacteria), what cytokine is released by the antigen presenting cell
TGF-beta
IL-1
IL-6
IL-23
