Human CD8+ T Cells

Peripheral blood CD8+ T cells, also referred to as cytotoxic T cells, are critical components of the adaptive immune response.  CD8 is a transmembrane glycoprotein which serves as a co-receptor for TCR (T Cell Receptor) to recognize antigens on major histocompatibility complex (MHC).  Once bound, CD8+ T cells kill the infected cell by secreting cytotoxic granules, containing granzymes and perforin, resulting in apoptosis of the target cell.