Double-negative (CD4-CD8-) lymphocytes bearing T-cell receptor alpha and beta chains in normal human skin.

Abstract
Double-negative (CD4-CD8-) T-cell receptor .alpha.- and .beta.-chain (TCR.alpha..beta.)-expressing lymphocytes have been identified in human skin. Two skin-derived lymphocyte cell lines (II-1 and II-2) expressing this phenotype were obtained. They each expressed full-length TCR .alpha.- and .beta.-chain transcripts and lacked TCR .gamma.- and .delta.-chain as well as CD4 and CD8 mRNAs. These polyclonal cell lines shared one predominant TCR .beta.-chain gene rearrangement. The CD3/TCR.alpha..beta. complexes were functionally competent as evidenced by their capacity to transduce activation signals resulting in cell proliferation, lymphokine secretion, and cytolytic activity. The demonstration of CD4-CD8- TCR.alpha..beta. lymphocytes as a subpopulation of the skin-associated immune system should contribute to understanding the biologic potential of this cell population as well as of this organ-specific immune system.