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How do helper T cells activate B cells?
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immune system
Stimulation of immune response by activated helper T cells. Activated by complex interaction with molecules on the surface of a macrophage or some other antigen-presenting cell, a helper T cell proliferates into two general subtypes, TH1 and TH2. These in turn stimulate the complex pathways of the cell-mediated immune response and the humoral immune response, respectively.
Helper T cells play a critical role in the immune system by stimulating B cells to produce antibodies. This process typically occurs after a helper T cell has been activated by an antigen and subsequently encounters a B cell that has already recognized the same antigen.12
The activation of a B cell by a helper T cell involves two primary mechanisms:
- Cell-to-cell interaction: A direct physical interaction occurs between the CD40 ligand on the surface of the activated helper T cell and the CD40 protein on the surface of the B cell.2
- Cytokine signaling: Activated helper T cells secrete cytokines—specifically those produced by the TH2 subpopulation—which interact with the B cell to provide additional stimulation.123
Once stimulated, the B cells multiply into clones and develop into plasma cells, which are responsible for secreting large quantities of antibodies into the circulation to fight infection.2