T Lymphocytes — Cell-Mediated

T-cell antigen presentation

T cells acquire pathogen antigens exclusively through antigen presentation.

T-cell binding requirements

The infected cell must display MHC I and a foreign antigen on MHC I.

CD8

A protein on cytotoxic T cells that recognizes the MHC I structure of an infected cell.

TCR in T cells

Recognizes the specific foreign antigen displayed on MHC I.

T-cell activation

Requires recognition of MHC I and antigen plus co-stimulation from a Helper T cell.

Interleukin-2 (IL-2)

A cytokine released by Helper T cells that helps fully activate T cells.

Cytotoxic T cells

Effector T cells that travel throughout the body and destroy cells infected by specific pathogens.

Memory T cells

T cells produced during clonal selection that remain for future exposure to the same pathogen.

T-cell clonal selection

Production of cytotoxic T cells and memory T cells from an activated T cell.

T-cell receptors

Surface receptors that allow T cells to recognize specific antigens.

T cells and viruses

T cells are particularly effective against virus-infected cells because infected cells display viral antigens on MHC I.