Legionella pneumophila-induced suppression of macrophage spreading in vitro

Abstract

Incubation of normal mouse resident peritoneal cell suspensions rich in macrophages with Legionella pneumophila whole cell vaccine or soluble preparations thereof resulted in marked inhibition of the ability of the cells to spread on glass surfaces during a 24-h period. This inhibition, however, was transient in that by day 2 to 3 after culture initiation only partial inhibition was evident, and by day 4 to 5 thereafter most of the treated macrophage cultures showed normal spreading activity. Suppression of macrophage spreading was evident not only with intact Legionella preparations and the sonic extract but also with a lipopolysaccharide-rich somatic antigen preparation and flagella. The suppressive effects of Legionella preparations on a functional activity of normal macrophages in vitro indicate that these bacteria may have a detrimental effect on an important activity of cells involved in the immune defense system.

Legionellosis in the Immunocompromised Patient

“…L. pneumophila has been found to produce an endotoxin-like substance 52,53 as well as a variety of extracellular products, [54][55][56] some of which appear to inhibit the function of phagocytic cells. 57,58 Animal studies have increased our understanding of the pathogenesis of acute Legionella pneumonia. Guinea pigs exposed to aerosols of I. pneumophila develop pneumonia that pathologically resembles the human disease.…”

Própolis verde brasileira: citotoxicidade e potencial anti-inflamatório in vitro

“…Friedman et al (1983) constataram que o extrato sonicado de L. pneumofilha, 10 ug/mL promoveu uma inibição de 89.2% do espraiamento.…”