CD4+ and CD8+ T cells Flashcards
Which cytokine(s) are made by Th1 cells?
IFN-y, TNF, IL-10
Which homing molecules are present on Th1 cells?
CXCR3 and CCR5, which bind to chemokines produced in tissues during innate immune responses
Ligands for E-selectin and P-selectin, which are expressed on endothelium at sites of strong inflammation
Which JAK kinases are activated by IFN-y?
JAK1 and JAK2
Which transcription factor is activated by IFN-y?
STAT1
What are 5 functions of IFN-y?
1) Activation of macrophages to kill phagocytosed microbes
2) Differentiation of CD4+ T cells to Th1 subset
3) Inhibition of Th2 and Th17 differentiation
4) Expression of proteins that contribute to enhanced antigen presentation and T cell activation (MHC molecules, B7 costimulators)
5) Activation of macrophages, DCs and other cells to produce cytokines that amplify the host response
Name some defects that can result in Mendelian susceptibility to mycobacterial disease.
Defects in IFN-y, IL-12, IL-12R, and STAT1
What is the cause of X-linked hyperIgM syndrome?
Mutations in the gene encoding CD40L
Which signals from Th1 cells activate macrophages?
IFN-y
CD40 (macrophage) - CD40L (T cell) interactions
Name three effects of macrophage activation by Th1 cells.
- Production of reactive oxygen species, nitric oxide, increased lysosomal enzymes
- Secretion of cytokines (TNF, IL-1, IL-12)
- Increased expression of B7 costimulators, MHC molecules
Name 4 functions of IL-4.
- B cell Ig heavy chain class switching to the IgE isotype
- Development of Th2 effector cells from naive CD4 T cells
- Alternative macrophage activation pathway
- Peristalsis in the gastrointestinal tract
Name 4 functions of IL-13.
- B cell Ig heavy chain class switching to the IgE isotype
- Alternative macrophage activation
- Peristalsis in the gastrointestinal tract
- Increased mucus secretion from airway and gut epithelial cells
Note that it is not involved in Th2 differentiation.
Name 2 functions of IL-5.
- Activation of mature eosinophils.
- Growth and differentiation of eosinophils.
Which cytokine(s) induces Th2 differentiation?
IL-4
Which homing molecules are present on Th2 cells?
CCR3, CCR4, and CCR8, which recognize chemokines highly expressed a sites of helminthic infection or allergic reactions, especially in mucosa
Which transcription factors are associated with Th2 cells?
STAT6, which induces GATA3
Which transcription factors are associated with Th1 cells?
STAT4 and STAT1, which induces T-BET
Which cytokine(s) inhibit Th2 responses?
IFN-y
Which cytokine(s) inhibit Th17 responses?
IFN-y, IL-4