Growth of Legionella pneumophila in thioglycolate-elicited peritoneal macrophages from A/J mice

Abstract

Legionella pneumophila is a facultative intracellular bacterium which readily grows in cultures of guinea pig and human mononuclear phagocytes. In this report, we demonstrate that the Legionella sp. also grows in thioglycolate-elicited macrophages obtained from A/J mice but not in cells from other mouse strains tested, such as BDF1, DBA/2, C3H/HeN, C57BL/6, and BALB/c. Growth of Listeria monocytogenes and interleukin-1 production in A/J mice were similar to their growth and production in other strains tested, and the growth of Staphylococcus epidermidis was restricted by A/J macrophages. This finding suggests that although A/J macrophages share functional capabilities with cells from other mouse strains, they differ in growth restriction capacity for the Legionella sp. Resident macrophages were less permissive than were thioglycolate-elicited cells in that resident cells from A/J mice failed to support the growth of Legionella pneumophila. Also, resident cells from BDF1 mice rapidly eliminated the bacteria, rather than merely restricting growth. This finding was also observed in in vivo studies in which thioglycolate pretreatment of mice resulted in the enhanced recovery of viable bacteria from the peritoneal cavity of mice infected intraperitoneally. Higher numbers of bacteria were obtained from A/J mice and, in addition, this strain was more susceptible to the lethal effects of LegioneUa infection. These data suggest that, as with other intracellular bacteria, macrophages may serve a pivotal role in the early stages of Legionella infection and further suggest that the A/J mouse represents a useful animal model for the study of Legionella infection and immunity.

Restriction of Legionella pneumophila growth in macrophages requires the concerted action of cytokine and Naip5/Ipaf signalling pathways

“…Legionella pneumophila proliferates rapidly in macrophages derived from the A/J mouse strain (Yamamoto et al, 1988). In contrast, macrophages obtained from the C57BL/6 (B6) strain support considerably less bacterial replication, particularly after the first 24 h of infection (Derre and Isberg, 2004).…”

Legionella pneumophilaEnhC is required for efficient replication in tumour necrosis factor α-stimulated macrophages

“…The disease in humans is initiated by inhalation of contaminated water sources, and progresses as a result of intracellular replication of L. pneumophila in alveolar macrophages (McDade et al, 1977;Horwitz and Silverstein, 1980). Replication of the microorganism during the disease process can be reproduced in culture, as the microorganism can replicate in a wide array of both phagocytic and normally non-phagocytic mammalian cells (Horwitz and Silverstein, 1980;Daisy et al, 1981;Yamamoto et al, 1988).…”

Grouping of 20 reference strains of Legionella species by the growth ability within mouse and guinea pig macrophages

“…Since the ability to multiply in guinea pig macrophages is regarded to re£ect pathogenicity [9,19], guinea pig macrophages are useful for elucidating bacterial virulence factors. On the other hand, it is well known that L. pneumophila grows in A/J macrophages but not in macrophages of other mouse strains [20] and that the mouse strain di¡erence is genetically controlled by Lgn1 on the distal portion of mouse chromosome 13 [15,21,22]. Using mouse macrophages is useful for revealing genetically host defence mechanisms against legionellae.…”