Enhancement of Cytotoxicity of Human Peripheral Blood Lymphocytes by Interferon

Abstract

Human lung carcinoma cells persistently infected with mumps virus (Pc‐10/MpV) were lysed with human peripheral blood mononuclear leukocytes (PBML) obtained from seropositive donors who had anti‐mumps virus‐neutralizing antibody in their sera. This cellular cytotoxicity was due not to the cytotoxic T lymphocytes but mainly to the non‐T, non‐B cells, possibly related to natural killer (NK) cells. Moreover, it was concerned not with antibody against mumps virus antigens but with alpha‐interferon (IFN‐α) produced in the mixture of human PBML and Pc‐10/MpV cells, since this cellular cytotoxicity was suppressed by anti‐human IFN‐α rabbit serum. Exogeneous IFN‐α augmented the cytotoxicity of non‐T, non‐B cells, not T cells, for the uninfected Pc‐10 cells. IFN‐γ that had been induced by heat‐killed Listeria monocytogenes in PBML had the same capacity to augment NK activity did IFN‐α. © owned by Center for Academic Publications Japan (Publisher)