Influence Of Reticuloendotheliosis Virus On Local Mucosal Immunity In SPF Chicks

Reticuloendotheliosis(RE)is an immunosuppressive and neoplastic disease caused by the viral reticuloendotheliosis virus(REV).RE can cause immunosuppression and tumors in the affected poultry.The mucosal immune system is the body's first line of defense against external pathogens entering the body.The body's mucous membranes can recognize the body's invading antigens in a variety of ways,occurs immune response and eliminate the invading pathogens.In this study,1-day-old SPF chickens were used as the research object.Using detection methods such as HE,ANAE,immunohistochemical staining,real-time fluorescence quantitative PCR,and ELISA to detect the number of intraepithelial intraepithelial lymphocytes,the number of ANAE~+T lymphocytes,IgA,IgG,IgM producing cells and the expression levels of IL-2,IFN-?and TNF-?mRNA and their protein content in gland of Harder,Peyer's patch and caecal tonsil.The purpose of this study was to reveal the effect of REV infection on local mucosal immunity in chicks and provide new ideas for the prevention and treatment of REV.The results of the study showed that:(1)The number of chicks duodenum IEL of SPF chicks was significantly or extremely significantly higher than those of control group at 3-35 day post REV infection(P<0.05 or P<0.01).It was shown that IEL mediated chicks immune response against REV infection was enhanced.(2)The number of ANAE~+T lymphocytes in gland of Harder,Peyer's patch and caecal tonsil were significantly or extremely significantly lower than those of contral group at 14-35 day,7-35day and 7-35 day post REV infection(P<0.05 or P<0.01).It was shown that REV infection can lead to decreased cellular immune function in local mucosa-associated lymphoid tissue of chicks.(3)The number of IgA,IgM antibody-producing cells in gland of Harder and IgG producing cells in caecal tonsil were significantly or extremely significantly lower than those of contral group at 7-35 days post REV infection(P<0.05 or P<0.01);The number of IgM and IgA producing cells in Peyer's patch and caecal tonsil were significantly or extremely significantly lower than those of contral group at 3-35 days post REV infection(P<0.05 or P<0.01);The number of IgG producing cells in gland of Harder and Peyer's patch was significantly or extremely significantly lower than those of contral group at 14-35 days post REV infection(P<0.05 or P<0.01).It was shown that REV infection can lead to decreased humoral immune function in local mucosa-associated lymphoid tissue of chicks.(4)The expression of IL-2,IFN-?,and TNF-?mRNA and protein content in gland of Harder,Peyer's patch,and caecal tonsil were all significantly or extremely significantly higher than those of contral group post REV infection.It was shown that IL-2,IFN-?,and TNF-?were involved in local mucosal damage caused by REV infection.Through the detection of the above indicators,the effect of REV on the local mucosal immunity of chicks was revealed,providing new ideas for the prevention and treatment of REV.