T Cells

T Cells

Important cytokines
1. IL-2: T cell stimulator
2. IFN-gamma: stimulates macrophages
3. IL-10: inhibits T cells and macrophages
4. IL-4 and IL-5: B cell stimulators
Selection
1. Positive: thymic cortex
2. Negative: thymic corticomedullary junction
B cell activation
1. 1. Endocytosis of antigen by B cell
  1. 2. Antigen is presented to a Th cell by using the MHC II found on APCs
    1. 3. Use of costimulatory signal of CD40 receptor on B cells and CD40 ligand on Th cell
      1. 4. Steps 1-3 -> Th2 cell to generate IL-4, IL-5 and IL-6
Regulatory T cells
1. T regulatory CD4 cells
  1. Express CD4 and CD25
  2. Inhibit B cell antibody production
  3. Inhibit the generation of autoimmune diseases
2. T suppressor CD8 cells
  1. Suppress graft rejection
  2. Inhibit some autoimmune diseases
NK cells
1. Activity is enhanced by
  1. IL-12
  2. IL-2
  3. IFN-alpha
  4. IFN-beta
2. Induced to kill when exposed to
  1. Appropriate ratio of activation signals
  2. Absence of specific inhibitory signals (MHC I)
3. Secrete IFN-gamma -> macrophages
4. Identified with surface markers
  1. CD16
    1. Binds to constant region of antibodies
    2. Found on
      1. NK cells
      2. Macrophages
      3. Monocytes
      4. Neutrophils
    3. Recognize and kill immunoglobulin coated cells by ADCC
  2. CD56

Resumo de Recurso

	Criado por snlogel quase 11 anos atrás