Interleukin-4 promotes human CD8<sup>+</sup>T cell expression of CCR7
Seneviratne SL., Black AP., Jones L., Di Gleria K., Bailey AS., Ogg GS.
Despite strong evidence supporting a pathway of human T cell differentiation characterized by changes in the expression of CCR7, CD28, CD27 and CD62L, few studies have addressed the mechanisms of pathway regulation. Cutaneous lymphocyte-associated antigen (CLA)-positive skin-homing CD8+T cells expressed significantly elevated levels of activation markers compared with CLA-CD8+T cells in individuals (n = 27) with cutaneous atopic disease. Despite such an activated phenotype, CLA+T cells expressed significantly higher levels of CCR7 than a CLA-T cell subset. Interleukin (IL)-4 was found to dramatically promote CCR7 expression by antigen-specific CD8+cells. Furthermore, skin-homing CD8+T cells from individuals with severe disease produced significantly less IL-10 than those derived from mildly affected atopic subjects. Thus in a T-helper 2 dominated disease, tissue-specific CD8+T cells show altered CCR7 expression and cytokine production, which may contribute to continued lymph node homing, antigen presentation and disease. IL-4 promotes expression of CCR7, a marker linked to existing models of CD8+T cell differentiation. © 2006 The Authors.