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Replication of Legionella Pneumophila in Human Cells: Why are We Susceptible?

Arwa Abu Khweek1, Amal Amer

  • 1Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Center for Microbial Interface Biology and the Department of Internal Medicine, Ohio State University Columbus, OH, USA.

Frontiers in Microbiology
|June 21, 2011
PubMed

Insights

Legionella pneumophila causes Legionnaires' disease by multiplying within human immune cells. This review details its survival strategies and highlights human cell lines for studying this intracellular pathogen.

Area of Science:

  • Microbiology
  • Immunology
  • Cell Biology

Background:

  • Legionella pneumophila is the primary cause of Legionnaires' disease, a severe pneumonia.
  • This intracellular bacterium infects human alveolar macrophages and monocytes, leading to disease.
  • While most mouse strains restrict L. pneumophila, certain genetic knockouts and human cell lines support its replication.

Purpose of the Study:

  • To review the survival mechanisms of L. pneumophila within human cells.
  • To identify human-derived cell lines that support L. pneumophila replication.
  • To emphasize the utility of in vitro models for studying host-pathogen interactions.

Main Methods:

  • Literature review of L. pneumophila pathogenesis and host cell interactions.
  • Analysis of studies utilizing various human cell lines for L. pneumophila culture.
  • Examination of bacterial strategies for intracellular survival and immune evasion.

Main Results:

  • L. pneumophila employs multiple strategies to survive within human cells, including preventing phagosome-lysosome fusion and inhibiting apoptosis.
  • Human alveolar macrophages, monocytes, and specific phagocytic/non-phagocytic cell lines support L. pneumophila replication.
  • Genetic factors in mice (Nlrc4, caspase-1 deficiency) influence susceptibility.

Conclusions:

  • Understanding L. pneumophila survival mechanisms is crucial for combating Legionnaires' disease.
  • Human cell line models provide valuable platforms for investigating L. pneumophila pathogenesis.
  • These in vitro models facilitate reproducible studies of bacterial-host interactions at molecular and cellular levels.
Keywords:
NOD-like receptorsToll-like receptorsneuronal apoptosis-inhibitory proteinspathogen-associated molecular patterns

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