The peptides presented by MHC class II peptide molecules are
A) from plasma cells.
B) exogenous antigens.
C) endogenous antigens.
D) from T helper cells.
E) antibodies.

Question

Quizplus · Accepted Answer

MHC class II molecules present exogenous antigens, which are derived from external sources, such as bacteria or viruses, that have been engulfed by antigen-presenting cells. Plasma cells produce antibodies, not peptides presented by MHC class II. Endogenous antigens are presented by MHC class I molecules. T helper cells produce cytokines to activate other immune cells, but do not present peptides themselves. Antibodies are not presented by MHC class II molecules.

The Peptides Presented by MHC Class II Peptide Molecules Are