title: Protective immunity induced by recombinant protein CPSIT_p8 of Chlamydia psittaci.
abstract: Chlamydia psittaci is a zoonotic pathogen with a broad host range that can lead to severe respiratory and systemic disease in humans. Currently, an effective commercial vaccine against C. psittaci infection is not available. The chlamydial plasmid is an important virulence factor and encodes plasmid proteins that play important roles in chlamydial infection and the corresponding immune response. In this study, we assessed the efficacy of vaccination with plasmid proteins at preventing C. psittaci lung infection in a murine model. BALB/c mice were immunized intraperitoneally, three times at 2-week intervals, with purified recombinant CPSIT_p8 protein and then infected with C. psittaci. Immunization significantly decreased chlamydial load in the lungs of infected mice, resulted in a lower level of IFN-γ, and reduced the extent of inflammation. In vivo or in vitro neutralization of C. psittaci with sera collected from immunized mice did not reduce the amount of viable C. psittaci in the lungs of mice, indicating that CPSIT_p8-specific antibodies do not have neutralizing capacity. Furthermore, confocal fluorescence microscopy using a mouse anti-CPSIT_p8 antibody revealed that CPSIT_p8 was localized inside the inclusion of C. psittaci 6BC-infected cells. Our results demonstrate that CPSIT_p8 protein induces significant protective immunity against challenge with C. psittaci in mice and represents a promising new vaccine candidate for the prevention of C. psittaci infection.
authors.affiliation: Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China.|Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, 421001, China.
authors.forename: Mingxing
authors.initials: M
authors.lastname: Liang
authors.affiliation: Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China.
authors.forename: Yating
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China.|Department of Clinical Laboratory, Central Hospital of Xiangtan, Xiangtan, 411100, China.
authors.forename: Ou
authors.initials: O
authors.lastname: Ran
authors.affiliation: Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China.
authors.forename: Liesong
authors.initials: L
authors.lastname: Chen
authors.affiliation: Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Wang
authors.affiliation: Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China.
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Pathology, University of South China, Hengyang, 421001, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China. chaoqunc@aliyun.com.|Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, 421001, China. chaoqunc@aliyun.com.
authors.forename: Chaoqun
authors.initials: C
authors.lastname: Chen
authors.affiliation: Pathogenic Biology Institute, Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, China. yimouwu@sina.com.|Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, 421001, China. yimouwu@sina.com.
authors.forename: Yimou
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D058491:Bacterial Load; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D002690:Chlamydia Infections / Q000276:immunology / Q000517:prevention & control*; D002691:Chlamydophila psittaci / Q000276:immunology*; D003001:Cloning, Molecular; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D007114:Immunization; D007371:Interferon-gamma / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D011994:Recombinant Proteins; D007371:Interferon-gamma
keywords: C. psittaci; CPSIT_p8; Mouse; Plasmid protein; Protective immunity