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Published on: July 4, 2016

A family of variably expressed outer-membrane proteins (Vomp) mediates adhesion and autoaggregation in Bartonella

Peng Zhang1, Bruno B Chomel, Maureen K Schau

  • 1Division of Infectious Diseases, Department of Medicine, University of California-San Francisco, 521 Parnassus Avenue, San Francisco, CA 94143-0654.

Proceedings of the National Academy of Sciences of the United States of America
|September 7, 2004
PubMed

Insights

Bartonella quintana outer-membrane proteins (Vomp) are variably expressed during chronic infection, with some acting as adhesins. Gene deletion mechanisms drive this variation, impacting bacterial virulence.

Area of Science:

  • Microbiology
  • Pathogen Biology
  • Immunology

Background:

  • Bartonella species are Gram-negative bacteria causing persistent human infections.
  • Bacterial adhesion to host cells and extracellular matrix (ECM) is crucial for virulence.
  • Pathogens often modulate surface protein expression to evade immune responses.

Purpose of the Study:

  • To investigate changes in Bartonella quintana outer-membrane proteins (OMP) during prolonged bloodstream infection using a macaque model.
  • To identify and characterize novel adhesins involved in Bartonella pathogenesis.

Main Methods:

  • Development of a macaque animal model for Bartonella quintana infection.
  • Analysis of bacterial outer-membrane proteins (OMP) from chronic infection isolates.
  • Identification of a gene family encoding variably expressed outer-membrane proteins (Vomp).

Main Results:

  • Identified a family of four conserved, 100-kDa, variably expressed OMP (Vomp) in B. quintana.
  • Demonstrated that two Vomp proteins function as adhesins, binding to collagen and mediating autoaggregation.
  • Observed variable Vomp expression mediated by gene deletion in both animal models and human isolates.

Conclusions:

  • Bartonella quintana Vomp are multifunctional adhesins belonging to the YadA-like trimeric autotransporter family.
  • Variable expression of Vomp through gene deletion is a key mechanism for adapting to host environments during chronic infection.
  • Individual Vomp family members contribute distinct virulence properties, such as collagen binding and autoaggregation.

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