MHC-B haplotypes impact susceptibility and resistance to RSV-A infection.

Abstract

We investigated the impact of haplotype of major histocompatibility complex (MHC)-B on the outcome of infection of Synthetic Dam Line (SDL) broiler strain with Rous Sarcoma Virus (RSV). Genomic analysis of MHC-B haplotypes, revealed a total of 12 known standard haplotypes that constituted to twenty-five different genotypes and one new haplotype of 217 bp size, designated B. The inoculation of RSV-A in SDL chicks resulted in the development of tumors of progressive or regressive phenotypes with varying tumor profile index (TPI). Haplotypes B, B and Bhad low TPI scores (1 or 2) with less mortality and were resistant to RSV-A tumor. The haplotypes B, B, B, Band Bhad significantly higher TPI scores (5 or 6), indicating a susceptibility to RSV-A. The genotype, B /B, had a mean TPI score of 3.67 ± 1.33, which was closer to the resistant haplotype. Sequence analysis of the new haplotype (B) revealed 99.5% similarity with B2 haplotype. Metastases was observed in 44% of chicks and comprised of mixed fibrosarcoma and myxosarcoma.