EXPRESSION OF LY-6 ALLOANTIGEN DURING DIFFERENTIATION OF CYTOTOXIC T-CELLS

We have prepared anti‐Ly‐6.2 by immunization of (CBA/Ca × A‐Thy‐la)F1 with AKR/Crc lymphocytes and used the antiserum to study heterogeneity of peripheral T lymphocytes. The Ly‐6 alloantigen is found on all activated cytotoxic T cells studied, directed to a variety of different target antigens. The antiserum reveals heterogeneity among the precursors of T killer cells, i.e. allogeneic precursors are Ly‐6−, whereas the generation of cytotoxic cells to hapten‐modified syngeneic cells and xenogeneic cells is partially abrogated by serum pretreatment. Precursors of some in vivo primed responses are also Ly‐6+. These findings indicate that the expression of Ly‐6 antigen is, at least, partially related to the stage of T cell activation. The in vitro proliferative response of T cells to allogeneic Ia antigens is substantially reduced by pretreatment with anti‐Ly‐6.2 serum suggesting that this antiserum may be a useful tool for the study of heterogeneity in the Ly‐l+ pool of T cells. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim