title: Virulence associated ingestion of Legionella pneumophila by HeLa cells.
abstract: Invasion of HeLa cell monolayers by Legionella pneumophila was studied. Virulent L. pneumophila strains efficiently entered cultured HeLa cells whereas isogenic avirulent isolates were nearly 1000-fold less efficient at cellular entry. Animal passage of avirulent strains, which restored bacterial virulence, coincided with a return to the virulent parental level of HeLa cell invasion. Diminished HeLa cell invasion by avirulent strains was not a function of reduced bacterial association with the cell monolayer. These data suggest that ingestion of L. pneumophila by non-professional phagocytes is a virulence directed property.
mesh_terms: D000818:Animals; D002642:Chick Embryo; D006367:HeLa Cells; D006801:Humans; D007875:Legionella / Q000472:pathogenicity*; D010587:Phagocytosis; D012692:Serial Passage