BIIC Immunology Lecture 3_Cell Mediated Adaptive Immunity Part 2

Question 1

What is the primary function of TH1 t cells and and what cytokines do they secrete?

Answer 1

Defence against intracellular infections. They secreate IFN gama, IL-2, and TNF Alpha. They also express CD40L which activtes macrophages in a way similar to IFN gamma

Question 2

What cytokines does TH2 secrete? How does it effect M1 Macrophages?

Answer 2

They secrete IL-4, IL-5, and IL-13. They down regulate M1 macrophages and promote M2

Question 3

What cytokines does TH17 secrete and what do they do?

Answer 3

IL-17 and IL-22 which causes inflamation and recrute the other immune cells. IL-21 which causes undifferenciated CD4 t cells to be become TH17 effector cells

Question 4

How do CTL (cytotoxic t cells) kill target cells.

Answer 4

It requires cell to cell contact. Once this achieved there are three MOA that they use 1) Granzymes/Perforin 2) Fas/FasL 3) Cytotoxic Cytokine (TNF and lymphotoxin LT)

Question 5

Which cells express Fas and which express FasL

Answer 5

All cells express Fas. Only activated CD8 t cells (CTL) express FasL

Question 6

How does a super antigen function?

Answer 6

It binds any MHC to any TCR and holds it in place. Thus basically activates all T cells (CD4 and CD8) irrespective of specificity. This can cause a cytokine storm, unregulated t cell expansion, fever, shock, etc.

Question 7

What is scalded skin syndrome?

Answer 7

It is a result of a super antigen. It gives the apperance of burned skin. It is Nikolsky sign positive

Question 8

How do infected macrophages effect TH1 t cells?

Answer 8

The macrophage secrets IL-12. This causes the Th1 to secret more IFN gamms and CD40L, both of which promote causes the phagocyte to be more toxic