Ovine progressive pneumonia provirus levels associate with breed and Ovar-DRB1

Abstract

Previous studies initiated defining the role of host genetics in influencing the outcome of exposure to ovine progressive pneumonia virus. However, specific genes influencing host control of virus replication and disease progression have not been identified. This study, using 383 ewes of the Columbia, Polypay, and Rambouillet breeds, tested the hypothesis that host control of OPPV as measured by provirus levels in the peripheral blood associates with certain breeds and MHC class II Ovis aries (Ovar)-DRB1 expressed alleles. Rambouillet ewes were less likely to have measurable provirus levels as compared to Columbia ewes at ages 5 and 6 (P value < 0.02), and they exhibited lower provirus levels when compared to both Columbia and Polypay ewes of the same ages (P value < 0.05). The presence of DRB1*0403- or DRB1*07012-expressed alleles were significantly associated (P value = 0.019 and 0.0002, respectively) with lower OPP provirus levels but only were only found in 11% of the ewe flock. Analysis of each segregating amino acid in the beta1 domain of DR beta-chain revealed that amino acids Y31, T32, N37, T51, Q60, or N74 significantly associated (P value range = 0.0003-0.018) with lower OPP provirus levels, whereas amino acids H32, A38, or I67 associated (P value range = 0.013-0.043) with higher OPP provirus levels. These results suggest that Ovar-DRB1 contributes as one host genetic factor that controls OPP provirus levels, but does not fully account for the breed-specific OPP proviral differences.

MHC class II DR allelic diversity in bighorn sheep

“…MHC class II allelic variants have been associated with susceptibility/ resistance to several infectious diseases in DS, cattle, humans and chicken (Allen et al, 1996;Carrington and O'Brien, 2003;Dawkins et al, 1999;Herrmann-Hoesing et al, 2008;Hill et al, 1991;Zekarias et al, 2002).…”

Small Ruminant Lentiviruses: Strain Variation, Viral Tropism, and Host Genetics Influence Pathogenesis

“…Previous research has shown that although SRLV viral load is positively correlated with lesion severity in the host, significant breed differences in proviral concentrations indicate a host genetic component in susceptibility. 5,6 Although complete resistance would be the ideal host genetic trait, genetics that enable the host to maintain low viral load would be beneficial to decrease the overall consequence of disease. Maintenance of a low viral load may also be beneficial by decreasing risk of transmission to susceptible hosts.…”

Diagnostic Assays Used to Control Small Ruminant Lentiviruses

“…70 Recently, the genotypes of the major histocompatibility complex (MHC) class II DRB1 alleles and chemokine receptor 5 (CCR5) were evaluated within the context of OPPV peripheral blood provirus loads. 41,80 The MHC class II DRB1 was evaluated because previous literature suggested that MHC class II was a putative receptor for VISNA and possibly CAEV (Hullinger GA: 1993, A gp135 cellular receptor mediates infection of caprine synovial membrane cells by the lentivirus caprine arthritisencephalitis virus. PhD dissertation.…”