ABSTRACT
In order to study the functions of migration inhibitory factor (MIF) as macrophage activating cytokine and to investigate the possibility of MIF cDNA as gene therapeutic agent or adjuvant, we produced recombinant MIF (rMIF), anti-MIF antibody and pcDNA I plasmid containing mMIF cDNA (mMIF plasmid). We have investigated the effects of recombinant mMIF or mMIF plasmid on the expression of immune response-related gene in the mouse peritoneal macrophage or splenocyte. Recombinant mMIF produced by Baculovirus expression system was biologically active; it increased mRNA expression of tumor necrosis factor (TNF)-a, Interleukin (IL)-1, IL-6, granulocyte monocyte-colony stimulating factor (GM-CSF), nitric oxide synthase (NOS), Fas and Bcl-x when applied to the cultures of mouse peritoneal macrophage. Anti-mMIF antibody blocked these effects of mMIF on macrophage. Plasmid DNA carrying MIF cDNA inoculated into mouse peritoneal cavity also increased mRNA transcriptions from TNF, IL-1, IL-6, IL-12, GM-CSF, NOS genes of peritoneal macrophage. It enhanced proliferation of splenocyte stimulated with phorbol myristate acetate and IL-2 mRNA expression of splenocytes. Frorn these results, we conclude that rMIF is a strong macrophage activating factor and especially MIF plasmid can be used as an immune potentiating DNA drug in gene therapy for cancer or DNA adjuvant in vaccination in future.