Pathogenesis of leptospirosis: interaction of Leptospira interrogans with in vitro cultured mammalian cells

Abstract

Interactions of virulent Leptospira interrogans with murine monocyte-macrophage-like J774A.1 cells and Vero (African green monkey kidney fibroblasts) cells from attachment to internalization were investigated by a series of morphological analysis. Fontana silver staining revealed that only the pathogenic leptospires were able to attach to host cells and the attachment pattern varied depending on cell types that they interacted with. Transmission electron microscopy (TEM) analysis confirmed the formation of the leptospires-containing phagosomes and their colocalization with lysosomes in macrophages were verified by confocal microscopic analysis. Results of F-actin rearrangements examination indicated that virulent leptospires invaded host cells via a microfilament-independent pathway.

Carboxyfluorescein diacetate succinimidyl ester labeling method to study the interaction between Leptospira and macrophages

“…Several methods, such as Fontana silver staining, transmission electron microscopy (TEM) analysis, and immunofluorescence microscopy detection, have been used to elucidate the phagocytosis of leptospires by macrophages (Cinco et al, 1981;Liu et al, 2007;Toma et al, 2011). In our method, one of the major concerns is the ability to distinguish phagocytosed leptospires from those adhered to the cells.…”

Participação do componente C3 do sistema complemento murino na produção de anticorpos específicos e fagocitose contra <i>Leptospira interrogans</i>.

“…Dessa forma, os autores sugeriram que as leptospiras poderiam evitar a ativação de outros mecanismos de ação desencadeados por esta via fagocítica (Liu et al, 2007).…”

Interação de proteínas de membrana de Leptospira com os reguladores Fator H e C4BP do sistema complemento humano.

“…As leptospiras patogênicas interagem com diversos componentes de matriz extracelular como laminina, colágeno tipo I e IV, fibronectina, elastina e proteoglicanos (Breiner et al, 2009;Ito, Yanagawa,1987;. Cabe ressaltar que leptospiras patogênicas são micro-organismos altamente invasivos, capazes de aderir e invadir células hospedeiras mais eficientemente do que as estirpes não patogênicas e saprófitas (Fraga et al, 2011;Liu, 2007).…”