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Immuno-fluorescence Assay of Leptospiral Surface-exposed Proteins
10:47

Immuno-fluorescence Assay of Leptospiral Surface-exposed Proteins

Published on: July 1, 2011

Chlamydia pneumoniae major outer membrane protein is a surface-exposed antigen that elicits antibodies primarily

K Wolf1, E Fischer, D Mead

  • 1Laboratory of Intracellular Parasites, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratory, Hamilton, Montana 59840, USA. kwolf@niaid.nih.gov

Infection and Immunity
|April 9, 2001
PubMed

Insights

The major outer membrane protein (MOMP) of Chlamydia pneumoniae is surface-exposed and immunogenic, contrary to previous beliefs. This finding supports the development of new vaccines and diagnostic tools for Chlamydia pneumoniae infections.

Area of Science:

  • Microbiology
  • Immunology
  • Bacterial Pathogenesis

Background:

  • The major outer membrane protein (MOMP) of Chlamydia trachomatis is a known surface antigen eliciting antibodies.
  • In contrast, Chlamydia pneumoniae MOMP was considered non-surface-exposed and immunorecessive, leading to questions about immune response focus.
  • Discrepancies in MOMP properties between C. trachomatis and C. pneumoniae suggested differences in epitope recognition.

Purpose of the Study:

  • To investigate the surface exposure and immunogenic properties of Chlamydia pneumoniae MOMP.
  • To define conformational epitopes on C. pneumoniae MOMP recognized by specific monoclonal antibodies.
  • To assess the potential of C. pneumoniae MOMP as a target for vaccines and diagnostics.

Main Methods:

  • Generation and characterization of Chlamydia pneumoniae-specific monoclonal antibodies (MAbs), GZD1E8 and RR-402.
  • Immunoprecipitation assays using MAbs to identify target antigens.
  • Mass spectrometry analysis to confirm protein identity.
  • In vitro infectivity neutralization assays.
  • Analysis of human sera from C. pneumoniae-positive donors.

Main Results:

  • Monoclonal antibody GZD1E8 recognizes a surface-exposed conformational epitope on C. pneumoniae MOMP.
  • GZD1E8 demonstrated potent in vitro neutralization of C. pneumoniae infectivity.
  • Both GZD1E8 and RR-402 MAbs immunoprecipitated C. pneumoniae MOMP, confirming its surface localization.
  • Human sera from C. pneumoniae-positive individuals recognized MOMP, indicating its immunogenicity.

Conclusions:

  • Chlamydia pneumoniae MOMP is surface-exposed and immunogenic, challenging previous assumptions.
  • The identified conformational epitopes on MOMP are targets for neutralizing antibodies.
  • These findings have significant implications for developing effective Chlamydia pneumoniae vaccines and diagnostic assays.

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