Expression profiles of genes within a subregion of chicken major histocompatibility complex B in spleen after Marek's disease virus infection

Major histocompatibility complex has previously been shown to influence the resistance of chicken to Marek's disease virus (MDV). However, little is known about expression of other genes in the MHC-I and II pathway after MDV infection. This study aimed at investigating 8 immune-related genes in the MHC core region that affects host responses to MDV. Spleens of infected and age-matched uninfected chickens were removed at 4, 7, 14, 21, and 28 d postinfection for gene expression detection using real-time PCR. Different expression patterns of MHC-I and II pathway genes were observed in the spleen. In the MHC-I pathway, the expression of transporter of antigen protein 1 (TAP1), transporter of antigen protein 2 (TAP2), and transporter of antigen protein-binding protein (TAPBP) genes was significantly increased in the spleen of MDV-infected than that of uninfected chickens. It indicated that host antivirus responses were generated to enhance antigen presentation. However, MHC-II pathway genes showed contrary trends. Classical MHC-II β chain major gene (BLB2) and nonclassical class II genes [DM α chain gene (DMA), DM β chain gene-1 (DMB1), and DM β chain gene-2 (DMB2)] had consistent lower transcripts in spleens of MDV-infected than that of uninfected chickens, which reflected that MDV interfered with multiple components of the MHC-II pathway. Overall, expression of most genes in the MHC core region was altered; moreover, the genes in endogenous and exogenous antigen presentation pathways had different expression patterns in the spleen after MDV infection.