title: Identification and characterization of an immunodominant 28-kilodalton Coxiella burnetii outer membrane protein specific to isolates associated with acute disease.
abstract: Coxiella burnetii causes acute Q fever in humans and occasional chronic infections that typically manifest as endocarditis or hepatitis. Isolates associated with acute disease were found to be distinct from a group of chronic disease isolates by a variety of biochemical parameters and in a guinea pig fever model of acute disease, suggesting a difference in virulence potential. We compared antigenic polypeptides among C. burnetii isolates and found an immunodominant 28-kDa protein in acute group isolates but not in chronic group isolates (T. Ho, A. Hotta, G. Q. Zhang, S. V. Nguyen, M. Ogawa, T. Yamaguchi, H. Fukushi, and K. Hirai, Microbiol. Immunol. 42:81-85, 1998). In order to clone the adaA gene, the N-terminal amino acid sequence of adaA was determined and a 59-bp fragment was amplified from Nine Mile phase I DNA by PCR. The putative gene fragment was used to screen a lambda ZAP II genomic DNA library, and an open reading frame expressing a 28-kDa immunoreactive protein was identified. Sequence analysis predicted a gene encoding an approximately 28-kDa mature protein with a typical signal sequence. The adaA (acute disease antigen A) gene was detected in acute group C. burnetii isolates but not identified in chronic group isolates by PCR and Southern blotting. A typical signal peptide was predicted in adaA, and specific antibody to adaA reacted with the purified membrane fraction of acute group isolates by Western blotting, suggesting that adaA is exposed on the outer surface of C. burnetii. adaA was overexpressed in pET23a as a fusion protein in Escherichia coli to develop anti-recombinant adaA (anti-radaA) specific antibody, which recognized a approximately 28-kDa band in acute group isolates but not in chronic group isolates. In addition, immunoblotting indicates that radaA reacted with sera derived from animals infected with acute group isolates but did not react with sera from animals infected with chronic group isolates. These results support the idea that an adaA gene-targeted PCR assay and an radaA antigen-based serodiagnostic test may be useful for differential diagnosis of acute and chronic Q fever.
authors.affiliation: Department of Medical Microbiology and Immunology, 407 Reynolds Medical Building, Texas A & M University System Health Science Center, College Station, TX 77843-1114, USA.
authors.forename: Guoquan
authors.initials: G
authors.lastname: Zhang
authors.forename: Ho
authors.initials: H
authors.lastname: To
authors.forename: Kasi E
authors.initials: KE
authors.lastname: Russell
authors.forename: Laura R
authors.initials: LR
authors.lastname: Hendrix
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Hideto
authors.initials: H
authors.lastname: Fukushi
authors.forename: Katsuya
authors.initials: K
authors.lastname: Hirai
authors.forename: James E
authors.initials: JE
authors.lastname: Samuel
mesh_terms: D000208:Acute Disease; D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D016997:Coxiella burnetii / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity*; D006801:Humans; D015151:Immunoblotting; D016056:Immunodominant Epitopes / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011778:Q Fever / Q000276:immunology / Q000382:microbiology* / Q000503:physiopathology; D017422:Sequence Analysis, DNA; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D016056:Immunodominant Epitopes; C582900:acute disease antigen A, Coxiella burnetii
references.citation: Infect Immun. 2002 Dec;70(12):6741-50
references.pmid: 12438349
references.citation: J Gen Microbiol. 1988 Jul;134(7):1795-1805
references.pmid: 2469774
references.citation: J Gen Microbiol. 1990 Jun;136(6):1099-107
references.pmid: 2384744
references.citation: J Gen Microbiol. 1991 Feb;137(2):269-76
references.pmid: 1673152
references.citation: Gene. 1991 Jul 15;103(1):113-8
references.pmid: 1879692
references.citation: Infect Immun. 1991 Dec;59(12):4735-9
references.pmid: 1937836
references.citation: Infect Immun. 1993 Feb;61(2):470-7
references.pmid: 8423075
references.citation: Antimicrob Agents Chemother. 1993 Sep;37(9):1733-6
references.pmid: 8239576
references.citation: Microb Pathog. 1993 Sep;15(3):177-85
references.pmid: 8271918
references.citation: Eur J Epidemiol. 1994 Aug;10(4):427-34
references.pmid: 7843346
references.citation: FEMS Microbiol Lett. 1995 Jan 15;125(2-3):275-80
references.pmid: 7875575
references.citation: Microbiology. 1995 Nov;141 ( Pt 11):2861-71
references.pmid: 8535514
references.citation: Microbiol Immunol. 1995;39(9):663-71
references.pmid: 8577279
references.citation: Infect Immun. 1998 Jan;66(1):132-9
references.pmid: 9423849
references.citation: Microbiol Immunol. 1997;41(11):871-7
references.pmid: 9444329
references.citation: Microbiol Immunol. 1998;42(2):81-5
references.pmid: 9572039
references.citation: Microbiol Immunol. 1998;42(6):423-8
references.pmid: 9688076
references.citation: Infect Immun. 1998 Dec;66(12):5882-8
references.pmid: 9826369
references.citation: Clin Microbiol Rev. 1999 Oct;12(4):518-53
references.pmid: 10515901
references.citation: FEMS Microbiol Lett. 1999 Nov 15;180(2):249-54
references.pmid: 10556719
references.citation: Proc Natl Acad Sci U S A. 2003 Apr 29;100(9):5455-60
references.pmid: 12704232
references.citation: Infect Immun. 2003 Aug;71(8):4717-23
references.pmid: 12874353
references.citation: Infect Immun. 2004 Feb;72(2):844-52
references.pmid: 14742528
references.citation: Ann Intern Med. 1979 Sep;91(3):400-2
references.pmid: 475167
references.citation: Microbiol Rev. 1983 Jun;47(2):127-49
references.pmid: 6348504
references.citation: Infect Immun. 1985 May;48(2):359-65
references.pmid: 3988339
references.citation: Infect Immun. 1985 Sep;49(3):775-9
references.pmid: 4030104
references.citation: Infect Immun. 1987 May;55(5):1144-50
references.pmid: 3570458
references.citation: Ann N Y Acad Sci. 1990;590:514-22
references.pmid: 2378474