L08: Inflammasomes and intro to acquired immunity

Question 1

Summary of Generation of CTL against Viral Antigen

Answer 1

1. Infected DC moves to LN
2. CD8 T cell activation by infected DC
3. Proliferation and gain of CTL effector function. Migration in blood to site of infection
4. Killing of virally infected cell presenting Ag on MHC class 1. No requirement for costimulation.

Question 2

Summary of Generation of CTL against Viral Antigen - P2

Answer 2

TCR recognises peptide
CD8 directly binds MHC1 (intracellular peptide)
Virus has dsRNA detected by PAMP in cytosol turning on B7 expression
CTL kills infected cell in presence of both signal 1 and 2
DC which activates CTL is infected itself.

Question 3

Summary of Generation of T helper 1 (Th1)

Answer 3

1. DC in tissue acquires Ag and encounters PAMP
2. Maturation + migration
3. Mature DC in lymph node activates CD4 T cell
4. T cell proliferates and differentiates into Th1 cell
5. T helper migrates in blood to inflammatory site
6. T helper cell helps macrophage kill ingested organisms

Question 4

Summary of Generation of T helper 1 (Th1) - p2

Answer 4

1. Ag is taken up from outside environment and peptide displayed on MHC2. PAMP recognised by TLR which upregulates B7.
2. PAMP activation tells cell to move to lymph node where there will be a T cell which recognises Ag displayed.
3. CD4 binds MHC 2 (extracellular pathogen).
4. DC expresses B7 and produces cytokines (IL-12) which induces T cell to differentiate into a Th1 cell
5. Th1 proliferates, differentiates and migrates through the blood to the inflammatory site to help macrophages kill the same antigen

Question 5

Summary of generation of T helper 2 (Th2)

Answer 5

1. DC in tissue acquires Ag and encounters PAMP
2. Maturation and migration
3. Mature DC in LN activates CD4 T cell
4. T cell proliferates and differentiates into TH2 cell
5. B cell takes Ag via BCR and presents peptides to Th2 cell
6. T helper cell helps B cell proliferate and differentiate into Ab-producing plasma cell