Identification of T cell lymphoma tumor antigens on human T cell lines

All human T lymphoblast cell lines have been derived from subjects with leukemia secondary to thymic lymphoblastic lymphoma, a T cell malignacy, suggesting that such lines represent established cultures of neoplastic T cells. Based on this observation, we prepared rabbit antisera to T cell line HSB‐2, removed reactivity for histocompatibility antigens and normal T cells by absorption with autocthonous B cell line CCRF‐SB and normal thymocytes, and tested the absorbed antisera by complement‐dependent cytotoxicity against a panel of normal and malignant cells. A representative antiserum reacted with all 4 T cell lines (mean cytotoxic index = 56) and with tumor cells from 4 patients with T cell lymphma (mean cytotoxic index = 50) but did not react with tumor cells from 6 patients with other types of leukemias (mean cytotoxic index = 2), with 3 B cell lines (mean cytotoxic index = 1), normal peripheral blood lymphocytes (mean cytotoxic index = 5), or normal thymocytes (mean cytotoxic index = 6). We conclude that appropriately absorbed antisera to human T cell lines detect T cell lymphoma tumor antigens.