Chapter 11- T cell activation

Question 1

Describe the 3 Signals that lead to activation of T cells.

Answer 1

• Provided by Ag-specific TCR engagement with CD3
• Costimulatory signals/ligands expressed by APC (CD80/86) and on TCR CD28
• cytokines

Question 2

Describe which immediate, early and late genes are activated upon T cell activation.

Answer 2

immediate: transcription factors
early: IL-2
late= various adhesion molecules

Question 3

How do T cells differentiate into the effector and memory cells?

Answer 3

CD4 and CD8 cells leave the Thymus, recognize MHC-ag complexes and bind to them, some become effector cells that secrete cytokine and help B cells and others become memory cells.

Question 4

Which cytokines determine if we have Th1 or Th2 cells?

Answer 4

Th1: has lots of IFN-gamma
TH2: IL4 and 5