The priming of helper T cells

摘要: Before helper T cells and B can interact to produce specific antibody, the antigen-specific cell precursors must be primed. Priming is a fairly abrupt event which occurs in vivo about 5 days after immunization. involves several steps: Antigen uptake, processing, surface expression bound class II MHC molecules by an antigen presenting cell, recirculation trapping of lymphoid tissue, proliferation differentiation. Helper express CD4, but not all CD4 are cells. The signals required for clonal expansion differ from those other critical antigen-presenting priming appears macrophage, second signal growth macrophage product interleukin-1.