Molecular cloning and characterization of CD3ε in Chinese domestic goose (Anser cygnoides).

CD3 is one of the most important cell surface markers of T lymphocytes which play an important role in signal transmission of antigen recognition. In this study, goose CD3ε gene was cloned by touchdown PCR with the template of goose thymus cDNA. The complete open reading frame of goose CD3ε encoded 178 amino acid residues with a 21 signal peptide. Sequence alignments showed that goose CD3ε had an amino acid sequence similarity to duck (80.3%) and chicken (66.3%). The extracellular domain of goose CD3ε was efficiently expressed as fusion protein in Escherichia coli, purified by a Ni-NTA agarose column, and the purified recombinant protein was used to produce anti-GoCD3εex polyclonal antibodies. The characteristics of PAb were identified by Western blot, cellular ELISA, IFA, FCM, and LSCM analysis. These results may be useful for a better understanding of goose CD3ε and have a foundation for the study of T cell mediated immune mechanism in waterfowl.