Molecular cloning of a Bacteroides caccae TonB-linked outer membrane protein identified by an inflammatory bowel disease marker antibody.

Abstract

Commensal enteric bacteria are a required pathogenic factor in inflammatory bowel disease (IBD), but the identity of the pertinent bacterial species is unresolved. Using an IBD-associated pANCA monoclonal antibody, a 100-kDa protein was recently characterized from an IBD clinical isolate of Bacteroides caccae (p2Lc3). In this study, consensus oligonucleotides were designed from 100-kDa peptides and used to identify a single-copy gene from the p2Lc3 genome. Sequence analysis of the genomic clone revealed a 2,844-bp (948 amino acid) open reading frame encoding features typical of the TonB-linked outer membrane protein family. This gene, termed ompW, was detected by Southern analysis only in B. caccae and was absent in other species of Bacteroides and gram-negative coliforms. The closest homologues of OmpW included the outer membrane proteins SusC of Bacteroides thetaiotaomicron and RagA of Porphyromonas gingivalis. Recombinant OmpW protein was immunoreactive with the monoclonal antibody, and serum anti-OmpW immunoglobulin A levels were elevated in a Crohn's disease patient subset. These findings suggest that OmpW may be a target of the IBD-associated immune response and reveal its structural relationship to a bacterial virulence factor of P. gingivalis and periodontal disease.

• Authors: B Wei, H Dalwadi, L K Gordon, C Landers, D Bruckner, S R Targan, J Braun
• Journal: Infection and immunity (Infect Immun) Vol. 69 Issue 10 Pg. 6044-54 (Oct 2001) ISSN: 0019-9567 [Print] United States
• PMID: 11553542 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antibodies, Bacterial
• Antibodies, Monoclonal
• Bacterial Outer Membrane Proteins
• Bacterial Proteins
• Immunoglobulin Fab Fragments
• Membrane Proteins
• OmpW protein, Bacteroides caccae
• Recombinant Fusion Proteins
• tonB protein, Bacteria

Topics

• Amino Acid Sequence
• Antibodies, Bacterial (immunology)
• Antibodies, Monoclonal (immunology)
• Bacterial Outer Membrane Proteins (genetics, immunology)
• Bacterial Proteins
• Bacteroides (genetics, immunology)
• Cloning, Molecular
• Crohn Disease (immunology)
• Genes, Bacterial
• Humans
• Immunoglobulin Fab Fragments (immunology)
• Membrane Proteins
• Molecular Sequence Data
• Recombinant Fusion Proteins (immunology)
• Sequence Analysis, DNA
• Sequence Homology, Amino Acid