This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Beare, P. A. Articles by Heinzen, R. A. PubMed PubMed Citation Articles by Beare, P. A. Articles by Heinzen, R. A.

 Previous Article  |  Next Article 

Clin. Vaccine Immunol. doi:10.1128/CVI.00300-08
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Candidate Q fever serodiagnostic antigens revealed by immunoscreening a Coxiella burnetii protein microarray

Coxiella Pathogenesis Section, Laboratory of Intracellular Parasites, and Genomics Unit, Research Technology Section, Research Technology Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, 59840; Department of Microbial and Molecular Pathogenesis, Texas A&M Health Sciences Center, College Station, Texas, 77843; Department of Medicine, University of California Irvine, Irvine, California, 92697; and Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, 99164

^* To whom correspondence should be addressed. Email: rheinzen{at}niaid.nih.gov.

	Abstract

Q fever is a widespread zoonosis caused by Coxiella burnetii. Diagnosis of Q fever is usually based on serological testing of patient serum. The diagnostic antigen of test kits is formalin-fixed phase I and phase II organisms of the Nine Mile reference strain. Deficiencies of this antigen include 1) potential for cross reactivity with other pathogens, 2) an inability to distinguish between C. burnetii strains, and 3) a need to propagate and purify C. burnetii, a difficult and potentially hazardous process. Consequently, there is a need for sensitive and specific serodiagnostic tests utilizing defined antigens, such as recombinant C. burnetii protein(s). Here we describe use of a C. burnetii protein microarray to comprehensively identify immunodominant antigens recognized by antibody in the context of human C. burnetii infection or vaccination. Transcriptionally active PCR (TAP) products corresponding to 1988 C. burnetii open reading frames (ORFs) were generated. Full-length proteins were successfully synthesized from 75% of the ORFs by using an Escherichia coli-based in vitro transcription and translation system (IVTT). Nitrocellulose microarrays were spotted with crude IVTT lysates and probed with sera from acute Q fever patients and individuals vaccinated with Q-Vax. Immune sera strongly reacted with approximately 50 C. burnetii proteins including previously identified immunogens, an ankyrin repeat-domain containing protein, and multiple hypothetical proteins. Recombinant protein corresponding to selected array-reactive antigens was generated and immunoreactivity confirmed by ELISA. This sensitive and high throughput method for identifying immunoreactive C. burnetii proteins will aid development of Q fever serodiagnostic tests based on recombinant antigen.