title: Recombinant interleukin-2-induced polyclonal proliferation of in vitro unstimulated human peripheral blood lymphocytes.
abstract: Human peripheral blood mononuclear cells as well as T-cell-enriched or T-cell-depleted populations were found to proliferate in response to recombinant interleukin-2 (IL-2) in vitro in the absence of a lectin preactivation signal. This proliferative response was detected at Day 2, peaked at Day 5, and was dependent on the concentration of IL-2 used. At the initiation of culture, these cells did not appear to be activated as determined by the expression of Tac antigens. In cultures of unfractionated T-cell-enriched suspensions, high concentrations of IL-2 resulted in preferential expansion of the OKT8+ population, although both OKT4+ and OKT8+ cells proliferated in response to IL-2 when cultured alone. These studies demonstrate that human lymphocytes obtained by standard fractionation procedures from peripheral blood are capable of proliferation in response to IL-2 without in vitro preactivation signals given by the addition of mitogens or antigens to cultures. These findings suggest that in vivo IL-2, in the absence of other exogenous stimuli, may directly influence immune responses and thus may have a potential role as a clinical immunopharmacologic agent.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2; D008213:Lymphocyte Activation / Q000187:drug effects*; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7