FIG. 2.

CD8⁺ T cell effector function. (A) Cytotoxicity can be induced through a delivery of granzymes and perforin. Perforin forms pores in target cell membranes, allowing delivery of granzymes to the cytosol, where granzymes induce apoptosis through activation of caspases and the mitochondrial pathway. Binding of Fas and TRAIL on the CD8⁺ T cell to their receptors FasL and TRAILR on the target cells also induced caspase activation. (B) Recognition of pMHC-I by the TCR results in cytotoxicity of the target cell as well as the release of antiviral cytokine and chemokines, which act on target cells and other immune cells. pMHC, peptide major histocompatibility complex.