Lymphokine-Activated-Killer-Mediated Lysis of Cells Infected with Typhus Group Rickettsiae Can be Inhibited by OKT3 Monoclonal Antibody

摘要

We recently described a population of human lymphocytes which were positive for T3 and T8 lymphocyte surface antigens and which were capable of lysing typhus group rickettsia-infected targets. These effectors could be generated by stimulating the peripheral blood mononuclear cells (PBMC) of immune individuals with typhus group rickettsia-derived antigen or by stimulating the PBMC of both immune and nonimmune individuals with interleukin-2. Because these effectors lyse both autologous and human lymphocyte antigen-mismatched targets infected with typhus group rickettsiae, and because stimulation with interleukin-2 alone is sufficient for their generation, we have classified these effectors as lymphokine-activated killers (LAK). To further understand the lytic process and to confirm the phenotypic characterization of these cytotoxic effectors, we designed a series of experiments to determine whether the LAK-induced lysis of typhus group rickettsia-infected targets could be inhibited by monoclonal antibodies directed against the T3, T4, and T8 lymphocyte surface antigens. Lysis was significantly inhibited by OKT3 monoclonal antibody but not by OKT4 or OKT8 monoclonal antibody. Keywords: Cytotoxicity; Killer cells; Rickettsia prowazekii; Rickettsia typhi; Immunology; Reprints. (aw)