This Article Full Text Full Text (PDF) Supplemental material Other Versions of this Article: IAI.00188-07v1 75/8/3833    most recent 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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ge, Y. Articles by Rikihisa, Y. Search for Related Content PubMed PubMed Citation Articles by Ge, Y. Articles by Rikihisa, Y.

 Previous Article  |  Next Article 

Infection and Immunity, August 2007, p. 3833-3841, Vol. 75, No. 8
0019-9567/07/$08.00+0     doi:10.1128/IAI.00188-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Surface-Exposed Proteins of Ehrlichia chaffeensis ^,

Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210

Received 5 February 2007/ Returned for modification 12 March 2007/ Accepted 14 May 2007

The surface proteins of Ehrlichia chaffeensis provide an important interface for pathogen-host interactions. To investigate the surface proteins of E. chaffeensis, membrane-impermeable, cleavable Sulfo-NHS-SS-Biotin was used to label intact bacteria. The biotinylated bacterial surface proteins were isolated by streptavidin-agarose affinity purification. The affinity-captured proteins were separated by electrophoresis, and five relatively abundant protein bands containing immunoreactive proteins were subjected to capillary-liquid chromatography-nanospray tandem mass spectrometry analysis. Nineteen out of 22 OMP-1/P28 family proteins, including P28 (which previously was shown to be surface exposed), were detected in E. chaffeensis cultured in human monocytic leukemia THP-1 cells. For the first time, with the exception of P28 and P28-1, 17 OMP-1/P28 family proteins were demonstrated to be expressed at the protein level. The surface exposure of OMP-1A and OMP-1N was verified by immunofluorescence microscopy. OMP-1B was undetectable either by surface biotinylation or by Western blotting of the whole bacterial lysate, suggesting that it is not expressed by E. chaffeensis cultured in THP-1 cells. Additional E. chaffeensis surface proteins detected were OMP85, hypothetical protein ECH_0525 (here named Esp73), immunodominant surface protein gp47, and 11 other proteins. The identification of E. chaffeensis surface-exposed proteins provides novel insights into the E. chaffeensis surface and lays the foundation for rational studies on pathogen-host interactions and vaccine development.

Published ahead of print on 21 May 2007.

Supplemental material for this article may be found at http://iai.asm.org/.

Editor: F. C. Fang

This article has been cited by other articles:

• Huang, H., Lin, M., Wang, X., Kikuchi, T., Mottaz, H., Norbeck, A., Rikihisa, Y. (2008). Proteomic Analysis of and Immune Responses to Ehrlichia chaffeensis Lipoproteins. Infect. Immun. 76: 3405-3414 [Abstract] [Full Text]  
• Kumagai, Y., Huang, H., Rikihisa, Y. (2008). Expression and Porin Activity of P28 and OMP-1F during Intracellular Ehrlichia chaffeensis Development. J. Bacteriol. 190: 3597-3605 [Abstract] [Full Text]  
• Noh, S. M., Brayton, K. A., Brown, W. C., Norimine, J., Munske, G. R., Davitt, C. M., Palmer, G. H. (2008). Composition of the Surface Proteome of Anaplasma marginale and Its Role in Protective Immunity Induced by Outer Membrane Immunization. Infect. Immun. 76: 2219-2226 [Abstract] [Full Text]  
• Zhang, C., Xiong, Q., Kikuchi, T., Rikihisa, Y. (2008). Identification of 19 Polymorphic Major Outer Membrane Protein Genes and Their Immunogenic Peptides in Ehrlichia ewingii for Use in a Serodiagnostic Assay. CVI 15: 402-411 [Abstract] [Full Text]  
• Ge, Y., Rikihisa, Y. (2007). Identification of Novel Surface Proteins of Anaplasma phagocytophilum by Affinity Purification and Proteomics. J. Bacteriol. 189: 7819-7828 [Abstract] [Full Text]