For more than 10 years the National Cancer Institute (NCI) has tested compounds for their ability to inhibit the growth of human tumor cell lines in culture (NCI screen). Work of Ken Paull [J. Natl.
View Article and Find Full Text PDFA recombinant amphotropic retrovirus was used to introduce the protein-coding region of the IL-2 receptor cDNA derived from HUT-102 cells into human CEM leukemic T-cells that lack these receptors. CEM T-cells that contained the virus expressed functional IL-2 receptors that transiently mediated five- to tenfold increases in [3H]thymidine incorporation following the addition of picomolar quantities of IL-2. Although IL-2 responsiveness was subsequently lost, it could be reinduced by cellular activation with the OKT11 monoclonal antibody.
View Article and Find Full Text PDFThe DNA sequence encoding all of the putative intracytoplasmic domain and most of the trans-membrane domain of the human IL 2 receptor was deleted from a full length receptor cDNA. After expression in mouse L cells, the resultant "anchor minus" cDNA was found to direct the synthesis of a secreted rather than membrane-associated form of the IL 2 receptor. The secreted receptor protein (44,000 to 46,000 Mr) retained the capacity to bind both IL 2 and the monoclonal anti-Tac antibody, as evidenced by retention on IL 2 and anti-Tac affinity columns, inhibition of [3H]-anti-Tac binding to HUT 102B2 cells, and partial inhibition of IL 2-induced CTLL proliferation.
View Article and Find Full Text PDFThe human T-lymphotropic viruses types I and II (HTLV-I and -II) have been etiologically linked with certain T-cell leukemias and lymphomas that characteristically display membrane receptors for interleukin-2. The relation of these viruses to this growth factor receptor has remained unexplained. It is demonstrated here that introduction of the trans-activator (tat) gene of HTLV-II into the Jurkat T-lymphoid cell line results in the induction of both interleukin-2 receptor and interleukin-2 gene expression.
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