Which immune cells are activated by antigen presentation via MHC molecules?

Which immune cells are activated by antigen presentation via MHC molecules?

• A. T-cells
• B. B-cells
• C. Neutrophils
• D. Eosinophils

Answer: (A)

Antigen presentation on MHC molecules activates T cells. Antigen-presenting cells display peptide fragments on MHC I or MHC II molecules. T cells have receptors that specifically recognize these peptide–MHC complexes, and with the necessary co-stimulatory signals, they become activated and proliferate into helper or cytotoxic T cells. MHC I mainly activates CD8+ cytotoxic T cells, which target infected cells, while MHC II activates CD4+ helper T cells, which coordinate the overall immune response. Other cells like B cells, neutrophils, or eosinophils aren’t activated primarily by recognizing peptide–MHC complexes.

Antigen presentation on MHC molecules activates T cells. Antigen-presenting cells display peptide fragments on MHC I or MHC II molecules. T cells have receptors that specifically recognize these peptide–MHC complexes, and with the necessary co-stimulatory signals, they become activated and proliferate into helper or cytotoxic T cells. MHC I mainly activates CD8+ cytotoxic T cells, which target infected cells, while MHC II activates CD4+ helper T cells, which coordinate the overall immune response. Other cells like B cells, neutrophils, or eosinophils aren’t activated primarily by recognizing peptide–MHC complexes.