In order to develop recombinant porcine Interferon-gamma (rPoIFN-gamma) to prevent porcine viral infection, PoIFN-gamma cDNA lacking the signal peptide was expressed in Pichia pastoris GS115 strain, and the effect of rPoIFN-gamma on porcine reproductive and respiratory syndrome virus (PRRSV) was investigated. The PoIFN-gamma gene was inserted into integrative vector pHIL-S1, and the recombinant GS115 strain (pHIL-S1/PoIFN-gamma) was constructed by homologues recombinant. The rPoIFN-gamma protein was 18 kD with an expressing yield of 18% was assayed by SDS-PAGE and Western blot, respectively. The anti-viral activity of rPoIFN-gamma was in the range of 450-540 u/mL. In addition, the effect of rPoIFN-gamma ant-PRRSV was determined using CPE50 method. The results indicated that high concentration of rPoIFN-gamma could inhibit PRRSV on Marc-145 cell line. The rPoIFN-gamma is a potential drug for prevention and treatment of various kinds of viral pig diseases.
Animals ; Antiviral Agents ; pharmacology ; Interferon-gamma ; biosynthesis ; genetics ; pharmacology ; Pichia ; genetics ; Porcine respiratory and reproductive syndrome virus ; drug effects ; Recombinant Proteins ; Swine

Interferons (IFNs) are natural proteins produced by wide variety of cells in response to viral infection or other biological inducers, and they execute diversified functions as antiviral defense, immune activation and cell growth regulation. Four genes encoding porcine interferons (PoIFN), PoIFN-alpha, PoIFN-gamma, PoIFN-alphagamma or PolFN-omega, were cloned and sequenced. The four types of porcine interferon genes were subcloned into the pET-His vector, and expressed in Escherichia coli Rosetta (DE3). The recombinant products were purified and renaturalized from inclusion bodies to obtain a native state of well biological activity. Antiviral activity assays for porcine interferons were performed and evaluated by standard procedures in following cell/virus test systems: Marc-145/PRRSV, Marc-145/VSV, PK-15/VSV, Vero/VSV or MDBK/VSV. The data showed that both PoIFN-alpha and PoIFN-alpagamma demonstrated significant antiviral activities, and the titer of them against PRRSV was up to 10(8) U/mg. PoIFN-gamma had approximately half or one-thirds antiviral activity of PoIFN-alpha. PoIFN-omega showed inconspicuous antiviral activity.
Amino Acid Sequence ; Animals ; Antiviral Agents ; pharmacology ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Interferon Type I ; biosynthesis ; genetics ; pharmacology ; Interferon-gamma ; biosynthesis ; genetics ; pharmacology ; Molecular Sequence Data ; Porcine respiratory and reproductive syndrome virus ; drug effects ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology ; Swine

Germanium biotite (GB) is an aluminosilicate mineral containing 36 ppm germanium. The present study was conducted to better understand the effects of GB on immune responses in a mouse model, and to demonstrate the clearance effects of this mineral against Porcine reproductive and respiratory syndrome virus (PRRSV) in experimentally infected pigs as an initial step towards the development of a feed supplement that would promote immune activity and help prevent diseases. In the mouse model, dietary supplementation with GB enhanced concanavalin A (ConA)-induced lymphocyte proliferation and increased the percentage of CD3+CD8+ T lymphocytes. In pigs experimentally infected with PRRSV, viral titers in lungs and lymphoid tissues from the GB-fed group were significantly decreased compared to those of the control group 12 days post-infection. Corresponding histopathological analyses demonstrated that GB-fed pigs displayed less severe pathological changes associated with PRRSV infection compared to the control group, indicating that GB promotes PRRSV clearance. These antiviral effects in pigs may be related to the ability of GB to increase CD3+CD8+ T lymphocyte production observed in the mice. Hence, this mineral may be an effective feed supplement for increasing immune activity and preventing disease.
Aluminum Silicates/administration & dosage/*therapeutic use ; Animal Feed/analysis ; Animals ; Antigens, CD3/metabolism ; Antigens, CD8/metabolism ; Antiviral Agents/administration & dosage/*therapeutic use ; Concanavalin A/metabolism ; Dietary Supplements/analysis ; Disease Models, Animal ; Ferrous Compounds/administration & dosage/*therapeutic use ; Germanium/administration & dosage/*therapeutic use ; Lung/immunology/virology ; Lymphocyte Activation/drug effects ; Lymphocytes/cytology/drug effects ; Lymphoid Tissue/immunology/virology ; Mice ; Mitogens/metabolism ; Porcine Reproductive and Respiratory Syndrome/*drug therapy/pathology/virology ; Porcine respiratory and reproductive syndrome virus/*drug effects ; Swine