Flow-cytometric measurement of CD4(sup -)8(sup -) T cells bearing T-cell receptor (alpha)(beta) chains, 1. Results for a normal population including two cases with unusually high frequencies

摘要

In this study we detected rare, possibly abnormal, T cells bearing CD3 surface antigen and T-cell receptor (TCR) (alpha)(beta) chains but lacking both CD4 and CD8 antigens (viz., TCR(alpha)(beta)(sup +)CD4(sup -)8(sup -) cells, as determined by flow cytometry). The TCR(alpha)(beta)(sup +)CD4(sup -)8(sup -)T cells were detected at a mean frequency of 0.63 (+-) 0.35 % (mean (+-) standard deviation) in peripheral blood TCR(alpha)(beta)(sup +) cells of 119 normal persons. Two unusual cases besides the 119 normal persons showed extremely elevated frequencies of TCR(alpha)(beta)(sup +)CD4(sup -)8(sup -)T cells, viz., approximately 5 % to 10 % and 14 % to 19 % in whole TCR(alpha)(beta)(sup +) cells. Both individuals were males who were otherwise physiologically quite normal with no history of severe illness, and these high frequencies were also observed in blood samples collected 2 or 8 years prior to the current measurements. The TCR(alpha)(beta)(sup +)CD4(sup -)8(sup -)T cells of the two individuals were found to express mature T-cell markers such as CD2,3, and 5 antigens, as well as natural killer (NK) cell markers, viz., CD11b, 16, 56, and 57 antigens, when peripheral blood lymphocytes were subjected to three-color flow cytometry. Lectin-dependent or redirected antibody-dependent cell-mediated cytotoxicities were observed for both freshly sorted TCR(alpha)(beta)(sup +)CD4(sup -)8(sup -) cells and in vitro established clones. Nevertheless, NK-like activity was not detected. Further, Southern blot analysis of TCR(beta) and (gamma) genes revealed identical rearrangement patterns for all the TCR(alpha)(beta)(sup +)CD4(sup -)8(sup -) clones established in vitro. These results suggest that the TCR(alpha)(beta)(sup +)CD4(sup -)8(sup -)T cells from these two mean exhibit unique characteristics and proliferate clonally in vivo. (author). (ERA citation 18:037382)