Preparation and immunization effect evaluation of Avian influenza H7N9 subtype virus-like particle vaccine

In order to obtain a H7 N9 subunit vaccine of Avian influenza that can replace commercial inactivated vaccine, point mutations in the transmembrane region of the HA gene of the H7 N9 subtype Avian influenza virus were carried out in this experiment, and a donor plasmid that simultaneously expressed the HA,NA and M1 genes was constructed. The donor plasmid was transformed into DH10 Bac competent cells to obtain recombinant Bacmid DNA;the correctly identified recombinant Bacmid was transfected into Sf9 cells, and a series of evaluations including hemagglutination test, Western-blot, SDS-PAGE,transmission electron microscopy, immunogenicity, were performed on the protein expressed by recombinant baculovirus. The results showed that the HA titer of the recombinant baculovirus expressed protein solution reached 1∶2 048,and Western-blot showed three specific bands. Transmission electron microscopy showed particles similar in structure to Avian influenza virus. The expressed virus-like particles（VLPs） protein was prepared into a vaccine, and the HI titer was slightly higher than that of the commercial vaccine. The results suggested that the three proteins can self-assemble into VLPs, and the VLPs vaccine had good immunogenicity.