A monoclonal antibody and functional study of malignant T cells of a patient with suppressor-T-cell lymphoma.

We describe the immunologic characteristics of malignant T cells of a T-cell lymphoma patient. The neoplastic cells in lymph node expressed OKT3+, OKT11-, E-rosetting-, OKT4-, OKT8+, OKIa1+, OKDR+ suppressor-T-cell phenotype. Functionally, these malignant T cells did not respond to phytohemagglutinin, but produced a good response to concanavalin A. A defect in expression of interleukin 2 receptors was evident in phytohemagglutinin-activated T cells. In vitro immunoglobulin production experiments demonstrated that patient's malignant T cells possess helper function on normal B cells to produce IgM, and suppressor function to produce IgG.