Question

multiple choice question
during costimulation during the activation of a t cell, the t cell binds to what?

a second protein on an antigen presenting cell
the lining of a blood vessel
a lipid on a macrophage
a carbohydrate on an antigen presenting cell

Explanation:

In T - cell activation, costimulation involves the T - cell binding to a second protein (like B7 on antigen - presenting cells, and CD28 on T - cells) on an antigen - presenting cell. The lining of a blood vessel is not related to T - cell costimulation. T - cell costimulation doesn't involve binding to a lipid on a macrophage or a carbohydrate on an antigen - presenting cell. So the correct option is the one about binding to a second protein on an antigen - presenting cell.

Answer:

A. A second protein on an antigen presenting cell