Endogenous antigens are presented by which class of MHC molecules?

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Multiple Choice

Endogenous antigens are presented by which class of MHC molecules?

Endogenous antigens are produced inside the cell, so they’re presented on MHC class I molecules. These molecules are found on nearly all nucleated cells and display short peptide fragments (about 8–10 amino acids) to CD8+ cytotoxic T cells. The peptides come from proteins degraded by the proteasome, then transported into the endoplasmic reticulum by TAP, where they are loaded onto MHC class I and sent to the cell surface. In contrast, exogenous antigens taken up from outside are displayed by MHC class II molecules to CD4+ helper T cells, and MHC class III refers to other immune-related proteins, not antigen presentation. So, endogenous antigens are presented by MHC class I.

Endogenous antigens are produced inside the cell, so they’re presented on MHC class I molecules. These molecules are found on nearly all nucleated cells and display short peptide fragments (about 8–10 amino acids) to CD8+ cytotoxic T cells. The peptides come from proteins degraded by the proteasome, then transported into the endoplasmic reticulum by TAP, where they are loaded onto MHC class I and sent to the cell surface.

In contrast, exogenous antigens taken up from outside are displayed by MHC class II molecules to CD4+ helper T cells, and MHC class III refers to other immune-related proteins, not antigen presentation. So, endogenous antigens are presented by MHC class I.

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