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The Acinetobacter baumannii Omp33-36 porin is a virulence factor that induces apoptosis and modulates autophagy in

Carlos Rumbo1, María Tomás2, Esteban Fernández Moreira1

  • 1Department of Microbiology, Complejo Hospitalario Universitario A Coruña-INIBIC, La Coruña, Spain.

Infection and Immunity
|August 27, 2014
PubMed

Insights

Acinetobacter baumannii Omp33-36, a porin protein, triggers cell death and aids bacterial survival within host cells. This outer membrane protein is a key virulence factor in A. baumannii infections.

Area of Science:

  • Microbiology
  • Immunology
  • Cell Biology

Background:

  • Acinetobacter baumannii is a significant hospital-acquired pathogen.
  • Understanding its virulence factors is crucial for combating infections.

Purpose of the Study:

  • To investigate the role of A. baumannii Omp33-36 protein in pathogenesis.
  • To elucidate the mechanisms by which Omp33-36 contributes to virulence.

Main Methods:

  • Characterization of Omp33-36 as a porin involved in water transport.
  • Analysis of Omp33-36-induced apoptosis and autophagy modulation in immune cells.
  • Intracellular persistence studies using autophagy inhibitors.
  • Validation in a mouse model of systemic infection.

Main Results:

  • Omp33-36 is a porin facilitating water passage and is released via outer membrane vesicles (OMVs).
  • Omp33-36 induces apoptosis and alters autophagy, leading to p62/SQSTM1 and LC3B-II accumulation.
  • Inhibition of autophagy enhances intracellular bacterial persistence and cytotoxicity.
  • Omp33-36 is confirmed as a virulence factor in macrophages and a systemic infection mouse model.

Conclusions:

  • Omp33-36 is a crucial virulence factor in Acinetobacter baumannii infections.
  • The protein contributes to pathogenesis by inducing apoptosis, modulating autophagy, and promoting intracellular survival.

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