Regulatory mechanisms for the expression of a functional β chain of interleukin 2 receptor on t4 chronic lymphocytic leukemia cells

Monoclonal antibodies, each recognizing interleukin 2 receptor (IL-2R)α or β were used to see the regulatory mechanisms of the expressions on leukemic cells from a patient with T4 chronic lymphocytic leukemia (T4-CLL). Cells from this patient expressed only IL-2Rβ and the expression was enhanced by medium cultivation. IL-1 enhanced the expression of not only IL-2Rβ but also IL-2Rα on the cells. Binding studies using ¹²⁵l-IL-2 snowed the presence of an intermediate receptor (734 sites/cell, Kd = 1.2nM) and a few high-affinity receptor (172 sites/cell, Kd = 132pM) on cells cultured with IL-1. IL-2 and IL-1 synergisti-cally promoted the proliferation of the cells, suggesting that the induced IL-2R was functional. In addition, anti-IL-1 antibodies inhibited IL-2Rβ expression by cultured cells, suggesting that it was dependent on IL-1 produced by the leukemic cells. These findings suggested that IL-1 might enhance the expression of IL-2Rβ in a subset of human T cells, and implied a role of IL-1 in the proliferation of the leukemic T cells.