title: Evaluation of recombinant proteins of Haemophilus parasuis strain SH0165 as vaccine candidates in a mouse model.
abstract: The recently completed genome sequence of Haemophilus parasuis strain SH0165 allowed us to screen putative OMPs for the development of recombinant vaccines. The objective of this study was to evaluate the immunogenicity and protective efficacy of three OMPs of H. parasuis. Three putative OMPs (SmpA, YgiW and FOG) were cloned, expressed and purified by Ni affinity chromatography using nitriloacetic acid resin. Mice were immunized either individually (individual protein, IP) or synergistically (synergistic protein, SP) with the recombinant proteins. A significant increase in IgG titer was detected in all protein-immunized mice. Isotyping studies revealed that the antibodies produced were predominantly IgG2a-type, indicating a predominant Th1 response. A significant increase was observed in IL-2, IL-4 and IFN-γ levels in the culture supernatants of splenocytes isolated from immunized mice. Furthermore, mice were challenged intraperitoneally with 6×10(9)CFU (5×LD(50)) of highly virulent homologous serovar 5 strain (SH0165) or 7.0×10(9) CFU (5×LD(50)) of the heterologous serovar 4 strain (MD0322) at fourteen days after the last immunization. All of the recombinant proteins enhanced survival and reduced histopathological lesions. Our results indicated that the three OMPs showed protection both individually and synergistically against infection with the highly virulent H. parasuis in mice.
authors: Hubei key laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430070, China.
authors: Fangyan
authors: F
authors: Yuan
authors: Shulin
authors: S
authors: Fu
authors: Jin
authors: J
authors: Hu
authors: Jinquan
authors: J
authors: Li
authors: Haitao
authors: H
authors: Chang
authors: Linlin
authors: L
authors: Hu
authors: Huanchun
authors: H
authors: Chen
authors: Yongxiang
authors: Y
authors: Tian
authors: Weicheng
authors: W
authors: Bei