INNATE - neutrophil, macrophage, dendritic cells, complement
ADAPTIVE - T, B-cells, circulating antibodies
T-cell differentiation (figure)
T-cell activation
MHC - signal 1
recognized by TCR
B7-CD28, IL-2 - signal 2
costimulatory molecule
activation requires 2 signals
Lymphocytes
T cell (60~70%)
- CD4+ help B cells make antibody and activate macrophage
- CD8+ kill virus infected cells directly
- allergy (type IV sensitivity)
- slow organ rejection
B cell(10~20%); found in superficial cortex of lymph nodes, white plulp in spleen
- make antibody, form plasma cells
- IgG antibodies to oppose bacteria, viruses
- allergy (type I hypersensitivity); IgE
- antibodies reject organ fast
