RÉSUMÉ
Objective:To express the head domain of influenza A virus hemagglutinin (HA) in a prokaryotic expression system and to evaluate its immunogenicity.Methods:The genes encoding the HA head domains of H1N1 and H3N2 influenza viruses were cloned into pET-22b(+ ) prokaryotic expression plasmid. After the induction with IPTG, the fusion proteins rH1N1-HA and rH3N2-HA containing HA head domain and His-tag were expressed and obtained from E. coli BL21. SDS-PAGE and Western blot was used to verify the expression of the recombinant proteins. Rabbits were immunized with multiple doses of the purified recombinant proteins to obtain polyclonal antibodies against the HA head domains of H1N1 and H3N2. The immunogenicity of the recombinant proteins was evaluated in BALB/c mice. Results:rH1N1-HA and rH3N2-HA induced protective antibodies (geometric mean titer ≥40) in mice and could be used as protective antigens. Polyclonal antibodies against rH1N1-HA and rH3N2-HA could be used as important materials for Western blot, ELISA and other immunological assays.Conclusions:The HA head domains prepared in this study could be used as protective antigens to induce protective antibodies in mice. Polyclonal antibodies against the HA head domains could be used for immunological and serological studies of influenza A viruses.