CDNA Cloning, Tissue Distribution And Immunological Function In Antiviral Response Of Goose CD4

CD4protein is a single chain transmembrane glycoprotein belonging to the immunoglobin superfamily that recognize the major histocompatibility complex (MHC) class]] molecules. It plays an important role in cell-mediated immunity. This article described several researches on goose CD4. First, it studied the molecular cloning and characterization of goose CD4. Then, it showed the tissue expression of CD4mRNA and the relative expression of CD4mRNA during the NGVEV infection. In the end, we used the immunohistochemical staining technique to detect the development and distribution of goose CD4in immune-related tissues.Molecular cloning and characterization of goose CD4. Here, the full-length cDNA of CD4in Chinese goose (Anser cygnoides) was cloned and identified. The goose CD4is1,940bp in length and encodes a single open-reading frame of480amino acids. The putative amino acid sequence of goose CD4is consisted of a signal peptide, four potential N-glycosylation sites, a transmembrane region and a cytoplasmic tail. The multiple sequence alignment and phylogenetic analysis suggested that goose CD4shared a higher similarity with avian than other vertebrates.The tissue expression of CD4mRNA. Semi-quantitative RT-PCR analysis showed that the highest level of CD4mRNA transcripts was presented in thymus, and relative lower in spleen, small intestine, brain and trachea. Low expression was seen in bursa of fabricius, cecal tonsil, cecum, skin, lung, kidney and liver, while in harderian gland, pancreas, heart, gizzard, proventriculus, kidney, liver and muscle with the lowest level. These data reveal that CD4molecule is extremely important for the goose immune system. In gosling, the CD4transcript was expressed with high abundance in thymus, relative lower in spleen, cecal tonsil and small intestine. However, in adult goose, high expression was seen in thymus, spleen and cecum, relative lower in cecal tonsil and small intestine. Accordingly, we speculate that the cellular immune system of gosling is imperfect compared with the adults.The distribution of goose CD4in immune-related tissues during development. The goose immune organs including thymus, spleen, bursa of fabricius, small intestine and harderian gland were taken at embryonic day (ED)20,1d,1w,2w,4w and adult day, respectively. The high level of CD4was showed in the immune-related tissues in bird aged ED20, and the expression was increased significantly with the maturity of these tissues. These results indicated that the structure and function of immune system were more perfect, and the goose CD4gene is age dependent.Effect of NGVEV infection on CD4mRNA levels in the immune-related tissue of gosling. Semi-quantitative RT-PCR analysis showed that during the course of NGVEV infection, the obviously increase of CD4gene expression were observed in spleen, bursa of fabricius and harderian gland. Interestingly, a notable decrease of CD4mRNA in the small intestine at5d PI and followed by increase of that at19d PI were showed.