Characterization of a subpopulation of human T lymphocytes reactive with an heteroantiserum to human brain.

A rabbit antiserum to human fetal brain reacted after suitable absorptions with a subpopulation of human normal T cells. The distribution of reactive T cells varied according to the organ tested: 23% of peripheral blood lymphocytes, 5% of tonsil lymphocytes, and less than 1% of thymocytes were positive. Reactive cells did not transform after phytohemagglutinin or pokeweed stimulation but were at least weakly stimulated by allogeneic cells. T-derived neoplastic cells from one case of T acute lymphoblastic leukemia, two patients with Sezary syndrome, and from three out of five cases of T chronic lymphocytic leukemias (CLL) yielded negative results. In contrast, all the leukemic cells from two other patients with T-derived CLL were positive suggesting a proliferation of homogeneous cells arising from only a subpopulation of T lymphocytes.