TCRzetadim lymphocytes define populations of circulating effector cells that migrate to inflamed tissues.
Zhang Z., Gorman CL., Vermi AC., Monaco C., Foey A., Owen S., Amjadi P., Vallance A., McClinton C., Marelli-Berg F., Isomäki P., Russell A., Dazzi F., Vyse TJ., Brennan FM., Cope AP.
The T-cell receptor zeta (TCRzeta) chain is a master sensor and regulator of lymphocyte responses. Loss of TCRzeta expression has been documented in infectious, inflammatory, and malignant diseases, suggesting that it may serve to limit T-cell reactivity and effector responses at sites of tissue damage. These observations prompted us to explore the relationship between TCRzeta expression and effector function in T cells. We report here that TCRzeta(dim) lymphocytes are enriched for antigen-experienced cells refractory to TCR-induced proliferation. Compared to their TCRzeta(bright) counterparts, TCRzeta(dim) cells share characteristics of differentiated effector T cells but use accessory pathways for transducing signals for inflammatory cytokine gene expression and cell contact-dependent pathways to activate monocytes. TCRzeta(dim) T cells accumulate in inflamed tissues in vivo and have intrinsic migratory activity in vitro. Whilst blocking leukocyte trafficking with anti-TNF therapy in vivo is associated with the accumulation of TCRzeta(dim) T cells in peripheral blood, this T-cell subset retains the capacity to migrate in vitro. Taken together, the functional properties of TCRzeta(dim) T cells make them promising cellular targets for the treatment of chronic inflammatory disease.