EXPRESSION AND ANTI-BACTERIAL IMMUNITY OF CD8α AND CD207 IN GRASS CARP

CD8α and CD207 are important phenotypic molecules on Dendritic cells (DCs), which play important roles in DCs-mediated adaptive immunity. To investigate their role in the anti-bacterial immune response of grass carp (Ctenopharyngodon idella) DCs, the extracellular regions of CD8α and CD207 were amplified from the cDNA of grass carp DCs, and the recombinant expression plasmid pET-32a- CD8α/CD207 was constructed and converted to competent cell Transetta (DE3), where it was expressed and purified to produce polyclonal antibodies against CD8α and CD207. The functions of grass carp CD8α and CD207 in the anti-bacterial immune process were revealed by qPCR, Western Blot and flow cytometry. The results showed that the prepared polyclonal antibodies recognized both prokaryotic expressed recombinant proteins and endogenous proteins at the individual and cellular levels. Functionally, after treatment with inactivated Aeromonas hydrophila to grass carp DCs, the expression levels of CD8α and CD207 were significantly up-regulated within 24h (P<0.05). Besides, the molecules of CD8α and CD207 play an important role in the process that the antigen presented by grass carp DCs stimulates the proliferation of mixed lymphocytes. Therefore, grass carp DCs exhibits a conservative immunophenotype and function similar to those in mammals, and the results of the study will provide a basis for elucidating the adaptive immune regulation mechanism mediated by grass carp DCs.