Infection of murine macrophage cell lines by Legionella pneumophila.

Legionella pneumophila causes pneumonia by infecting alveolar macrophages. Although several model systems have been used for L. pneumophila virulence studies, no detailed comparisons have been made between them. An ideal in vitro virulence model should be cost-effective, easy to obtain in large amounts and as relevant as possible to the actual disease. We compared the MH-S cell line to human peripheral blood monocyte-derived macrophages and the J774A.1 cell line. We found that the interactions of L. pneumophila with MH-S at the cellular level resemble those of human primary monocyte-derived macrophages, suggesting that these cells provide a valuable model for this bacterial pathogen.