In vitro parasite-monocyte interactions in human leishmaniasis: possible role of fibronectin in parasite attachment

Abstract

Leishmania spp. must attach to mononuclear phagocyte sirfaces before entering this host cell. We investigated the potential role of fibronectin in facilitating parasite attachment. Human plasma fibronectin bound to axenically cultured promastigotes, and promastigotes and amastigotes preferentially bound to fibronectin.coated cover slips. Promastigotes grown in the absence of fibronectin were strikingly deficient in their ability to attach to human monocytes compared with promastigotes grown in the presence of fibronectin. Rabbit anti-human plasma fibronectin antiserum decreased promastigote and amastigote attachment to monocytes. Immunoglobulin G F(ab')2 and Fab fragments also reduced the ability of amastigotes to bind to monocytes. Antiserum pretreatment of amastigotes foilowed by washing resulted in reduced parasite binding, whereas antibody pretreatment of monocytes did not. Addition of exogenous fibronectin did not enhance parasite attachment to monocytes. These findings suggest that Leishinania spp. can bind fibronectin and may utilize this glycoprotein to facilitate attachment to the mononuclear phagocytes that they infect.

Differences in human macrophage receptor usage, lysosomal fusion kinetics and survival between logarithmic and metacyclicLeishmania infantum chagasipromastigotes

“…promastigotes are taken up by mammalian macrophages through receptor-mediated phagocytosis. Macrophage surface receptors implicated in Leishmania recognition include CR1, CR3, MR, TLR2 and 9, the fibronectin receptor, and the receptor for advanced glycoconjugates (Blackwell et al, 1985;Mosser and Edelson, 1985;Wyler et al, 1985;Wilson and Pearson, 1986;Da Silva et al, 1989;Martinez-Salazar et al, 2008). During the current study we examined mechanisms that would explain recent reports that present conflicting data challenging the importance of MR in Leishmania phagocytosis (Akilov et al, 2007).…”

Involvement of complement and fibronectin in eosinophil‐mediated damage to Nippostrongylus brasiliensis larvae

“…Since ®bronectin is widely distributed in plasma, intercellular matrices and in¯ammatory exudates, and because it has multiple biological roles in cell-cell and cell±matrix interactions as well as phagocytosis, it is reasonable to expect the involvement of ®bronectin in parasitic diseases (Wyler 1987). Studies on the role of ®bronectin in parasitic diseases have focused largely on the function of this molecule in invasion of host cells by intracellular parasitic protozoa, Leishmania and Trypanosoma cruzi (Quaissi et al 1984, Wyler et al 1985. In addition, it has been also demonstrated that ®bronectin participates in the development of granulomatous in¯ammation and subsequent ®brosis induced by schistosome eggs (Nishimura et al 1985).…”

Hepatic extracellular matrix alterations in dogs naturally infected with Leishmania (Leishmania) chagasi

“…LN and FN, large mosaic proteins of the ECM, are important in the development and maintenance of cellular organization and are key components in several biological processes (Wyler 1987;Beck et al 1990;Bandyopadhyay et al 2003;Kulkarni et al 2008). FN has several functional domains that enable it to interact with cells, heparin, fibrin, collagen and immunoglobulins, and also with parasites (Wyler et al 1985;Kulkarni et al 2008). Macrophages can interact with different FN domains via different receptors.…”