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Chlamydia trachomatis OmcB protein is a surface-exposed glycosaminoglycan-dependent adhesin

Sanaa Fadel1, Adrian Eley1

  • 1Henry Wellcome Laboratories for Medical Research, Division of Genomic Medicine, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX, UK.

Journal of Medical Microbiology
|December 19, 2006
PubMed

Insights

Chlamydia trachomatis OmcB protein is a surface-exposed adhesin crucial for host cell attachment. Blocking OmcB significantly inhibits chlamydial infectivity by interfering with glycosaminoglycan receptor binding.

Area of Science:

  • Microbiology
  • Cell Biology
  • Immunology

Background:

  • Chlamydia trachomatis is an obligate intracellular bacterium.
  • Outer membrane proteins play vital roles in chlamydial pathogenesis and host cell interaction.
  • The OmcB protein's function and surface localization were previously unclear.

Purpose of the Study:

  • To characterize the Chlamydia trachomatis OmcB protein.
  • To determine the role of OmcB in bacterial adhesion and infectivity.
  • To identify host cell receptors for OmcB.

Main Methods:

  • Cloning and expression of the OmcB gene in Escherichia coli.
  • Generation of polyclonal antibodies against recombinant OmcB.
  • Infectivity inhibition assays using anti-OmcB serum and purified OmcB.
  • Binding assays with OmcB on various host cell lines, including GAG-deficient cells.

Main Results:

  • OmcB is a surface-exposed outer membrane protein of C. trachomatis.
  • Recombinant OmcB demonstrated significant inhibition (70%) of chlamydial infectivity.
  • OmcB directly binds to the surface of HeLa and Hec1B cells.
  • Binding to glycosaminoglycan (GAG)-deficient cells was markedly reduced, indicating GAG-like receptor interaction.

Conclusions:

  • OmcB functions as a chlamydial adhesin, mediating host cell attachment.
  • OmcB's interaction with GAG-like receptors is critical for C. trachomatis infectivity.
  • Targeting OmcB represents a potential strategy for inhibiting chlamydial infections.

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