02 T Cells

  • polysaccharide capsules not recognized

Antigen presentation

  • requires antigen presentation:

TCR

  • CD3: E and Delta

  • CD4: quarterback of immune response

CD4

MHC II

Co-Stimulation

TH1 and 2

  • macrophages secretes IL-12

T Cell cytokines

TH1 vs 2

  • Population of T cells; local cytokines favoring one or the other

  • intracellular infections protected from antibodies because inside cell, Th2 not useful, Th1 cell mediated useful

Granulomas

Leprosy

IBS

TH1 and macrophages

  • mutation in IL-12 or IFN-gamma receptors can lead to problem

IL12R deficiency

IFN-y

CD8

  • antibody, APC, macrophages, CD4 are ineffective against intracellular virus
  • CD8 react to MHC I and kill cell

MHC I

  • heavy chain = alpha

CD8 function

Regulatory T

TH17

Memory T

  • PPD test example of memory cell response

PPD

Superantigens

Thymus

  • positive selection selects for strongest binding to MHC
  • negative selection selects for weakest binding to self antigens

Aire