CD28 and CD57 define four populations with distinct phenotypic properties within human CD8⁺ T cells

After repeated antigen exposure, both memory and terminally differentiated cells can be generated within CD8 + T cells. Although, during their differentiation, activated CD8 + T cells may first lose CD28, and CD28 − cells may eventually express CD57 as a subsequent step, a population of CD28 + CD57 + (DP) CD8 + T cells can be identified in the peripheral blood. How this population is distinct from CD28 − CD57 − (DN) CD8 + T cells, and from the...