Modifications of the porcine interferon-alpha gene and its antiviral activity in vitro and in vivo

作者：Zhu, Y. P.; Xu, H.; Chen, Y. H.; Wang, Y.; Cen, L.; Guo, X. F.^*

来源：Revue de Medecine Veterinaire, 2011, 162(3): 143-149.

• Porcine interferon-alpha
• gene modification
• Pichia pastoris
• antiviral activity
• VSV
• GTEV
• PPRS

In order to up-regulate the expression of the porcine interferon-alpha (IFN-alpha) in Pichia pastoris, some rare codons encoding for 6 amino acids were modified to biased codons of P. pastoris. The modified gene was cloned into pPICZ alpha C electro-transformed X-33 cells for screening high Zeocin (TM)-resistant colonies. The recombinant modified or original porcine IFN-alpha proteins were detected by SDS-PAGE and Western blot. The codon modifications have enhanced by a factor 5 the protein expression. Using culture supernatants containing IFN-alpha on different cell lines infected with the VSV, the TGEV or the PPRSV, it was observed that the modified protein exhibited higher antiviral activities magnified 10-100 times for the TGEV and the PPRSV and even 300 times for the VSV compared to the original cytokine. Using the same IFN-alpha concentration, it was also noted that the anti-VSV activity of the modified cytokine was multiplied by 9. In an in vivo model of pigs infected with PRRSV-infected pigs, co-treatment with the IFN-alpha (modified or not) and antibiotics has led to significantly higher cure rates than treatment with antibiotics alone, and the modified protein was again significantly more efficient (P < 0.05). These results demonstrate the interest to genetically modify some rare codons in the porcine IFN-alpha gene for increasing the protein expression and its antiviral activities in vitro and in vivo.

• 出版日期2011-3
• 单位华南农业大学