How are superantigens able to uniquely activate large amounts of T cells?
A) Superantigens secrete many toxins that are able to activate many different T cells.
B) Superantigens are able to travel to the lymph node to interact directly with more T cells.
C) Superantigens bind to the TCR and MHC class II molecule outside the binding groove.
D) Superantigens bind to the TCR in the binding groove like other antigens but they have more epitopes than other antigens.

Question

Quizplus · Accepted Answer

The superantigens are able to bind the TCR and MHC class II molecules outside the binding groove. Therefore, they are not restricted to a few T cells that recognize a few epitopes of the antigen and the usual clonal expansion of those activated cells. Instead the superantigens are able to bind to outer portions of both the MHC class II molecule and the TCR, connecting the two cells and leading to activation of a large number of T cells. As a result of the large-scale T cell activation, large amounts of cytokines are released, which leads to increased vascular permeability, reduced blood flow, organ failure, hypovolemic shock, and potentially death.

How Are Superantigens Able to Uniquely Activate Large Amounts of T