Lecture 6 Flashcards
(44 cards)
Give 2 examples of cell-adhesion interactions that bring T cell and APC together
LFA-1 binding ICAM-1
CD2 binding CD58 (LFA-3)
What do low affinity LFA-1/ICAM-1 interactions facilitate?
TCR recognition of a peptide antigen on APC in the context of MHC
Naive T cell possesses an IL-2 receptor, but only expresses __ and __ chains on its surface.
𝛾 and β chains
What does CD28-dependent co-stimulation of activated T cell lead to?
expression of IL-2 receptor α chain, resulting in a receptor with high affinity for IL-2
What happens when CTLA-4 binds B7 molecules?
It delivers an inhibitory signal to activated T cells
How do cytotoxic T cells induce cell death?
(i) Through death receptors e.g. engagement of the Fas death receptor on its surface
(ii) Through secretion of IFN𝛾 & TNF, which can facilitate killing of the cell
(iii) Through release of perforin & granzymes, which activate caspases to induce apoptosis
Stimulation of APC through CD40 increases __ and __ , which both co-stimulate __ .
B7 and 4-1BBL
naive CD8+ T cell
Th1 cells are defined by production of which cytokines?
IFN𝛾 and TNFα
What cytokine drives differentiation into Th1?
IL-12
Th2 cells are defined by production of which cytokines?
IL-4, IL-5 and IL-33
Th2 immunity is important against __
Helminth parasites
Which T helper cell subset promotes the production of mucus?
Th2
How does IFN𝛾 affect macrophages?
It drives them towards a proinflammatory state (M1 phenotype)
What cytokines do Th17 cells produce?
IL-17 and IL-22
What two subsets of T helper cells are important inflammatory mediators in Crohn’s disease?
Th1 and Th17
Th17 cells are important for the immune response against…
extracellular bacteria (because they increase AMP production and neutrophil chemotaxis)
What cytokine do T follicular helper cells produce?
IL-21
How do Tfh cells help B cells?
- Help B cell differentiation & proliferation
- Boost Ab production, affinity maturation & isotype switching
What cytokines are produced by Tregs, and are they pro- or anti-inflammatory?
IL-10 and TGF-β
Anti-inflammatory
What cytokine drives differentiation into Tfh cell?
IL-6
CD4+ T cell subsets can cross-regulate each other’s differentiation through…
through the cytokines that they produce
How does IFN-𝛾 affect proliferation of Th cell subsets?
IFN-𝛾 promotes Th1 proliferation, but inhibits Th2 and Th17 proliferation
What two cell types are critically important for protection against viruses and tumours?
NK cells & CTLs
We can visualise the immunological synapse by staining for __
SMAC protein
