Phorbol diester induces expression of Tac antigen on human acute T lymphocytic leukemic cells.

摘要: In general, the human acute T lymphocytic leukemias are composed of malignant expansions immature cells lacking membrane receptors for cell growth factor (TCGF, interleukin 2) and significant immunoregulatory activity. We investigated whether cultured leukemic lines can be induced to differentiate express Tac antigen, a surface protein that contains TCGF-binding site, after exposure phorbol 12-myristate 13-acetate (PMA) and/or phytohemagglutinin (PHA). Reactivity anti-Tac with was studied by three techniques, including: 1) flow microfluorometry; specific binding [3H]anti-Tac; 3) receptor immunoprecipitation analysis SDS-PAGE. After PMA or without PHA, both JURKAT HSB-2 displayed antigen within 6 8 hr. Induction expression blocked actinomycin D, suggesting requirement new mRNA transcription. Induced contained approximately 7000 molecules per cell, these in dose-related manner purified TCGF but not insulin recombinant interferon-alpha. SDS-PAGE immunoprecipitates demonstrated present on were 2000 3000 daltons smaller than those PHA-activated normal lymphoblasts cells. PHA resulted marked secretion as well appearance antigen. activation alone, similarly expressed, level synthesis less 1% obtained dual induction PMA. These data indicate signals required identical, furthermore is obligately linked