Question

Toxic shock syndrome

Necessary process
Binding of T cell receptor by bacterial secretory products vs presentation of processed antigens by dendritic cells

Answer 1

T cell activation by bacterial secretory products and dendritic cells presenting processed antigens are two different mechanisms in the immune response.

Step-by-step explanation:

T cell activation by bacterial secretory products and dendritic cells presenting processed antigens are two different mechanisms in the immune response.

In the case of T cell activation by bacterial secretory products like toxic shock syndrome toxin (TSST), the toxin binds to the T cell receptor (TCR) outside of the antigen-binding cleft of MHC II molecules on antigen-presenting cells (APCs). This triggers an unregulated release of cytokines, resulting in an excessive inflammatory response.

On the other hand, dendritic cells play a role in presentation of processed antigens. They phagocytose pathogens and process antigenic proteins, selecting immunodominant epitopes that are loaded onto MHC II molecules and presented to T cells. This interaction is critical for the activation of T cells.