What is the function of class II MHC molecules?
A) They pick up exogenous "dead" antigens.
B) They seek out antigen molecules that have been synthesized inside a virus-infected cell.
C) Both of these are functions of class II MHC molecules.
D) Neither of these is a function of class II MHC molecules.

Question

Quizplus · Accepted Answer

Class II MHC molecules primarily present exogenous antigens, which are antigens that originate from outside the cell, to helper T cells. These antigens are typically taken up by antigen-presenting cells (such as dendritic cells, macrophages, and B cells) through processes like phagocytosis or endocytosis, processed, and then presented on the cell surface bound to class II MHC molecules. This is crucial for initiating immune responses against pathogens that do not directly infect host cells.

What Is the Function of Class II MHC Molecules