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Lysosome repair enables host cell survival and bacterial persistence following Chlamydia trachomatis infection

Wandy L Beatty1

  • 1Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA. beatty@borcim.wustl.edu

Cellular Microbiology
|April 25, 2007
PubMed

Insights

Chlamydia trachomatis evades host cell death by repairing plasma membrane damage with lysosomes. This process retains bacteria, enabling Chlamydia persistence within surviving host cells.

Area of Science:

  • Microbiology
  • Cell Biology
  • Infectious Diseases

Background:

  • Chlamydiae are obligate intracellular bacteria that replicate within a host-derived vacuole called the inclusion.
  • The infectious cycle culminates in the release of elementary bodies, often without host cell death for Chlamydia trachomatis strains.
  • The precise mechanisms governing host cell survival during Chlamydia infection remain incompletely understood.

Purpose of the Study:

  • To investigate the host cell events preceding Chlamydia trachomatis egress.
  • To elucidate the role of host cell repair mechanisms in preventing cell death during infection.
  • To identify factors influencing bacterial persistence within surviving host cells.

Main Methods:

  • Microscopy and immunofluorescence to track host cell and bacterial components.
  • Analysis of host cell membrane integrity using specific markers.
  • Biochemical assays to assess the role of calcium and actin dynamics.

Main Results:

  • Host cell plasma membrane integrity is compromised before inclusion membrane disruption.
  • Lysosome-associated membrane protein 1 (LAMP-1) appears on the cell surface, indicating lysosome involvement in membrane repair.
  • Calcium-dependent actin depolymerization is essential for lysosome-plasma membrane fusion and host cell survival.
  • Bacterial persistence is facilitated by the retention of residual bacteria within surviving host cells.

Conclusions:

  • Chlamydia trachomatis utilizes a host cell repair mechanism involving lysosome-plasma membrane fusion to ensure survival.
  • This lysosome-mediated repair process, dependent on calcium and actin dynamics, prevents host cell death.
  • The survival strategy allows for intracellular persistence of Chlamydia trachomatis, potentially influencing chronic infections.

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