Interleukin 2 production and interleukin 2 receptor expression by human immature leukemic T cells.

In order to determine the role of interleukin 2 (IL2) on the proliferation of leukemic cells from patients with T-cell acute lymphoblastic leukemia (T-ALL) we studied the production of IL2, the function of IL2 receptors (IL2R) expressed on T-ALL cells and their IL-2-dependent in vitro proliferation. Leukemic cells from six out of 17 T-ALL/T-cell non-Hodgkin's lymphoma patients with a prothymocyte (stage I) or a mature thymocyte (stage III), but not with a common thymocyte (stage II) phenotype, could proliferate, in a dose-dependent manner, in response to recombinant IL2 (rIL2) and anti-Tac and TU27 moAbs as well as polyclonal anti-IL2 purified immunoglobulin G could inhibit this IL2-induced cell proliferation. Both crude or/and Amicon-concentrated media conditioned by T-ALL cells from 10 out of 13 tested patients contained IL2 activity as assessed by colorimetric biological and immunoenzymatic assays; this biologic activity was due to a 14.

Effect of phorbol myristate acetate on T cell colony formation, interleukin-2 (IL-2) receptor expression and IL-2 production by cells from patients at all stages of HIV infection.

We and others have shown that several T cell responses induced by the mitogen phytohaemagglutinin (PHA), including T cell colony formation, IL-2 receptor (IL-2R) expression, and IL-2 production are impaired in patients with AIDS and lymphadenopathy syndrome (LAS). We investigated whether phorbol myristate acetate (PMA) could act in synergy with PHA (as it does in healthy subjects) to enhance in vitro T cell responses of patients at all stages of infection by HIV. In AIDS patients with opportunistic infections (AIDS/OI), PHA + IL-2 + PMA led to a total disappearance of T cell colonies in 10/11 patients, among whom six already displayed very low numbers of colonies induced by PHA + IL-2 (less than 50 colonies/5 x 10(4) cells).