title: Chloroform-Methanol Residue of Coxiella burnetii Markedly Potentiated the Specific Immunoprotection Elicited by a Recombinant Protein Fragment rOmpB-4 Derived from Outer Membrane Protein B of Rickettsia rickettsii in C3H/HeN Mice.
abstract: The obligate intracellular bacteria, Rickettsia rickettsii and Coxiella burnetii, are the potential agents of bio-warfare/bio-terrorism. Here C3H/HeN mice were immunized with a recombinant protein fragment rOmp-4 derived from outer membrane protein B, a major protective antigen of R. rickettsii, combined with chloroform-methanol residue (CMR) extracted from phase I C. burnetii organisms, a safer Q fever vaccine. These immunized mice had significantly higher levels of IgG1 and IgG2a to rOmpB-4 and interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α), two crucial cytokines in resisting intracellular bacterial infection, as well as significantly lower rickettsial loads and slighter pathological lesions in organs after challenge with R. rickettsii, compared with mice immunized with rOmpB-4 or CMR alone. Additionally, after challenge with C. burnetii, the coxiella loads in the organs of these mice were significantly lower than those of mice immunized with rOmpB-4 alone. Our results prove that CMR could markedly potentiate enhance the rOmpB-4-specific immunoprotection by promoting specific and non-specific immunoresponses and the immunization with the protective antigen of R. rickettsii combined with CMR of C. burnetii could confer effective protection against infection of R. rickettsii or C. burnetii.
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Fengtai, Beijing, China.
authors.forename: Wenping
authors.initials: W
authors.lastname: Gong
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Fengtai, Beijing, China; Department of Clinical Laboratory, the 105th Hospital of PLA, Hefei, Anhui, China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Fengtai, Beijing, China.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Xiong
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Fengtai, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiao
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Fengtai, Beijing, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Fengtai, Beijing, China.
authors.forename: Bohai
authors.initials: B
authors.lastname: Wen
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D002460:Cell Line; D002725:Chloroform / Q000494:pharmacology; D016997:Coxiella burnetii / Q000187:drug effects / Q000276:immunology*; D016207:Cytokines / Q000097:blood / Q000378:metabolism; D004195:Disease Models, Animal; D006801:Humans; D007114:Immunization; D008297:Male; D000432:Methanol / Q000494:pharmacology; D051379:Mice; D009500:Neutralization Tests; D011778:Q Fever / Q000276:immunology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology*; D012284:Rickettsia rickettsii / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D016207:Cytokines; D011994:Recombinant Proteins; D002725:Chloroform; D000432:Methanol