Effects of Methionine Deficiency on the B Lymphocyte and Immunoglobulins of Cecal Tonsil in Cobb Broilers

ABSTRACT The present study was conducted on one-day-old broilers to investigate the effects of methionine deficiency on B lymphocytes and immunoglobulins (sIgA, IgA, IgG, IgM) in the cecal tonsil of Cobb broiler chicken. Methods including immunohistochemistry (IHC), western blot (WB), quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) and Enzyme-Linked Immuno Sorbent Assay (ELISA) were used, and the study lasted for 6 weeks. It was found that the IgA+ B lymphocytes mainly existed in the diffuse lymphoid tissues and lymphoid follicles of the cecal tonsil. The data indicated that the number of IgA+ B lymphocytes was decreased in the methionine deficiency group, and the WB and qRT-PCR results suggested that the protein and mRNA expression of CD19 were reduced in the methionine deficiency group. Besides, the contents of sIgA, IgA, IgG and IgM determined by ELISA decreased in the methionine deficiency group. It could be concluded that methionine deficiency exerts significantly negative effects on the humoral immune function of the intestinal mucosal immunity.