1Ph.D. Student in Biotechnology, Department of Pathobiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
2Department of Pathobiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
3Fellow Member of Academy of Science of Iran, Tehran, Iran
4Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
5Department of Parasitology, Pasteur Institute, Tehran, Iran
6Department of Biotechnology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
Interferon gamma (IFN-γ) is one of the key cytokines in defining T helper 1 lymphocyte immune responses. In this study, the bovine IFN-γ gene was cloned from spleen tissue RNA using the reverse transcription-polymerase chain reaction (RT-PCR). IFN-γ cDNA was sub-cloned and expressed in mammalian expression plasmid (pcDNA3.1(+)) under the control of the human cytomegalovirus (CMV) promoter. The predicted amino acid (aa) sequence of bovine IFN-γ compared with corresponding known sequence from bovine (Bos taurus) was 100% identity and with ovine, caprine, camel, lama, equine, canine, feline, human, mice and chicken cytokine was 95, 95, 86, 83, 77, 75, 75, 61, 44 and 35%, respectively. Invitro expression of recombinant bovine IFN-γ (rBoIFN-γ) and secretion to culture medium was confirmed by ELISA test. Maximum expression of rBoIFN-γ occurred at 96 and 144 h after transfection in COS-7 cells. These results showed that pcDNA3.1 expression vector and COS-7 cells transfected by diethylaminoethyl (DEAE)-dextran allowed the high level expression of bovine IFN-γ gene and the release of protein in supernatant of cell culture.