Highly efficient action of autocrine mouse interferon-γ expressed via a retroviral vector

Abstract

Following infection with a mouse interferon-γ (IFN-γ)-producing retrovirus, various types of mouse cell lines began to constitutively secrete IFN-γ in the culture medium, but the IFN-γ production level varied according to cell type. Effects of the IFN-γ on the IFN-γ-producing cell itself (autocrine effects) were examined. In the IFN-γ-producing cells, the expression of the major histocompatibility complex class I genes was augmented; this augmentation was remarkable in T cell lines tested in this work, regardless of their poor IFN-γ production. This autocrine effect was highly efficient and could not easily be abrogated by the exogenous addition of anti-IFN-γ antibodies. Such antibody resistance was also observed for the antiviral effect of the autocrine IFN-γ on an IFN-γ gene-transferred fibroblast line. These results suggest that apparently low titers of physiological IFN-γ might exert strong in vivo autocrine and possibly paracrine effects.