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Pseudomonas aeruginosa eliminates natural killer cells via phagocytosis-induced apoptosis

Jin Woong Chung1, Zheng-Hao Piao, Suk Ran Yoon

  • 1Cell Therapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong, Daejeon, Republic of Korea.

Plos Pathogens
|August 29, 2009
PubMed

Insights

Pseudomonas aeruginosa (PA) invades natural killer (NK) cells, causing their death and promoting tumor metastasis. Restoring NK cell numbers can mitigate this PA-induced metastasis, offering insights into immunocompromised patient relapse.

Area of Science:

  • Immunology
  • Microbiology
  • Oncology

Background:

  • Pseudomonas aeruginosa (PA) is an opportunistic pathogen causing severe illness and relapse in immunocompromised individuals.
  • NK cells are crucial for immune surveillance against pathogens and cancer.

Purpose of the Study:

  • To investigate the interaction between PA and NK cells.
  • To elucidate the mechanisms by which PA affects NK cell function and impacts tumor metastasis.

Main Methods:

  • Transmission electron microscopy to visualize PA internalization into NK cells.
  • Assessment of NK cell apoptosis pathways (PI3K, caspase 9, MAP kinase, ROS).
  • In vivo studies of tumor metastasis and the effect of NK cell adoptive transfer.

Main Results:

  • PA invades NK cells, inducing phagocytosis-induced cell death (PICD).
  • PA infection augments tumor metastasis and reduces NK cell numbers in vivo.
  • Adoptive transfer of NK cells mitigated PA-induced metastasis.
  • PA invasion involves PI3K activation, leading to caspase 9-dependent apoptosis via MAP kinase and ROS.

Conclusions:

  • PA phagocytosis by NK cells is a critical mechanism contributing to disease relapse in immunocompromised patients, particularly cancer patients.
  • Understanding PA-NK cell interactions provides insights into immune evasion strategies of opportunistic pathogens.

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