Cytotoxic T cells assess which markers on affected cells?

Cytotoxic T cells primarily recognize and bind to MHC Class I markers on infected or abnormal cells. MHC Class I molecules are present on nearly all nucleated cells in the body and serve as a platform to display endogenous peptides, which can include fragments of proteins from pathogens such as viruses. When a virus infects a cell, viral proteins are processed and presented by MHC Class I molecules on the cell surface.

The interaction between cytotoxic T cells and MHC Class I molecules is critical for the immune response. If a cytotoxic T cell recognizes a foreign peptide presented by MHC Class I, it can initiate a response that leads to the destruction of the infected cell. This is essential for controlling viral infections and eliminating cells that have become cancerous.

In contrast, MHC Class II markers are primarily recognized by helper T cells, which play a different role in the immune response, such as aiding B cells in producing antibodies. Pathogen-associated markers and antibody markers are not directly assessed by cytotoxic T cells in the context of their primary function. Therefore, the recognition of MHC Class I is essential for the activation and function of cytotoxic T cells in immune surveillance and response.