title: Polyclonal activation of human lymphocytes and induction of cytotoxic lymphocytes by streptococcal preparations.
abstract: Polyclonal activation of human peripheral blood lymphocytes (PBLs) in vitro by preparations of Streptococcus pyogenes Su strain (OK-432) and other heat-killed strains was investigated. The streptococcal preparations tested induce a proliferative response of PBLs via interleukin-2 (IL-2)-independent pathways. The proliferative response is accompanied by the generation of lymphoblastic cells (LBCs), which consist of heterologous lymphocyte populations: CD4+ helper type of T cells, and CD4-CD8- double-negative (DN) lymphocytes, including both CD3+ TcR gamma + T cells and CD2+CD3- immature type of T or non-T cell type of lymphocytes. Almost all the LBCs express Leu19, TfR (transferrin receptor), LFA-1 and CD38 (OKT10) antigens, which are expressed on activated T cells, NK cells and some other lymphocytes. The proliferative response of human PBLs is also accompanied by the generation of potent cytotoxic activity against NK-sensitive and -resistant targets. C-dependent cytolysis and cell sorting experiments of OK-432-activated LBCs revealed that both CD3+ and CD3- types of CD4-CD8- DN lymphocytes, but not CD4+ helper T cells, may be major populations responsible for the cytotoxicity induced. On the other hand, CD4-CD8- T cells may be required for the proliferation of PBLs and generation of cytotoxic effector cells. These results suggest that the OK-432 and other streptococcal preparations stimulate the human PBLs in vitro to induce the proliferation/activation of CD4+ T cells, mediating the following generation of DN cytotoxic effector lymphocytes.
authors.affiliation: Department of Microbiology, Tohoku University, School of Dentistry, Sendai, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: M
authors.initials: M
authors.lastname: Fujii
authors.forename: H
authors.initials: H
authors.lastname: Satoh
authors.forename: T
authors.initials: T
authors.lastname: Itoh
authors.forename: H
authors.initials: H
authors.lastname: Rikiishi
authors.forename: K
authors.initials: K
authors.lastname: Kumagai
mesh_terms: D004261:DNA Replication; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000276:immunology; D007700:Kinetics; D008213:Lymphocyte Activation; D010844:Picibanil / Q000276:immunology; D013297:Streptococcus pyogenes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism
chemical_list: D007376:Interleukin-2; D010844:Picibanil