Genetic analysis of sheep pox virus targeting host immunity evasive genes

Abstract

The Capripoxvirus genus includes sheep pox virus (SPV), a contagious viral infection of small ruminants primarily affecting sheep. It is characterized by severe skin lesions, fever, diarrhea, difficulty breathing, pulmonary involvement, and death. This leads to enormous economic losses for sheep farmers. Recently, numerous cases of individual and multiple cases of SPV have been reported with failure of treatment and control strategies. This suggests that SPV may undergo genetic mutations affecting host immunity by blocking or inhibiting host immunity proteins more efficiently. Therefore, in this study, three host-immunity evasive viral genes, including soluble interferon-gamma receptor-like protein (IFN-γ), G-protein coupled chemokine receptor (GPCR), and inhibitory Major Histocompatibility Complex (MHC class 2) were sequenced. To do this, 125 suspected cases were examined and then subjected to PCR technique, which revealed 40 SPV positive 32%. The sequence results of most local strains revealed high similarity to the local vaccine strain, and other strains originated from neighboring countries such as Saudi Arabia and Turkey. However, some strains show genetic diversity. Notably, the designed primers efficiently diagnose SPV and could be useful in viral quantification for future studies. This may also explain the efficiency of the vaccination protocol in Iraq. This may help to improve our understanding of SPV infection and its control.

Keywords

• spv
• evasion
• diagnosis