CD8 T cells comprise a powerful bra

CD8 T cells comprise a powerful branch of the adaptive immune system, yet were notformally recognized until long after the discovery of antibody. CD8 T cells contribute tothe eradication of intracellular infections and to the control of many chronic infections.There is tempered optimism that CD8 T cell memory elicited via vaccination may holdthe key to manufacturing protective immunity against pathogens that cause chronicinfections in humans. The specificity and destructive capabilities of CD8 T cells may alsobe harnessed for the eradication of tumors. However, CD8 T cells also contribute to avariety of clinical difficulties such as immune mediated pathology, rejection of organtransplants, and autoimmunity. Clearly, learning how to safely generate protective longlived CD8 T cell memory and how to control or eliminate specific unwanted responsescould deliver substantial clinical rewards, and there is a great need for continuedresearch on the biology and therapeutic potential of these cells. Herein, we recount thehistorical developments leading to the discovery of CD8 T cells, highlight a few of theimportant discoveries that have followed, and discuss some of the critical issues on thehorizon.