In vitro Entamoeba histolytica adhesion to human endothelium: a comparison using two strains of different virulence

Abstract

Extraintestinal dissemination of Entamoeba histolytica is frequently manifested by the life-threatening amebic liver abscess (ALA). The hepatic establishment of amebas implies invasion of blood vessels and contact with the endothelium. By means of a fluorescence-based quantitative adhesion assay, we assessed the binding to human endothelial cells of two E. histolytica strains of different virulence. The highly virulent strain (L-A) adhered substantially more strongly to unstimulated endothelium than the non-virulent one (BG3). Attachment of L-A was increased by treatment of endothelial cells with interleukin-1 beta (IL1 beta). Other proinflammatory cytokines such as interferon-gamma (IFN gamma) and tumor necrosis factor-alpha (TNF alpha) did not modify the spontaneous adhesion capacity of amebas. For purposes of comparison we also performed adhesion of the parasites to skin fibroblasts. Adhesion to this cell type was quite low (< 10%). Parasite virulence, differential adhesive capacity to endothelial cells, and modulation of the latter phenomenon by proinflammatory factors (IL1 beta) may influence the evolution and outcome of extraintestinal amebiasis, especially hepatic abscesses.

Entamoeba histolytica: focal adhesion kinase and Erk phosphorylation are altered in the cytoskeleton mutant BG-3

“…Furthermore, our results also show that cytoskeleton integrity plays an important role in adhesion to collagen and possibly in adhesion to host tissues. The present results, together with the findings reported by Serrano et al (1994), and Flores-Romo et al (1997, support the proposal that cytoskeleton integrity plays an important role in the pathogenesis of amebiasis. Fig.…”

“…Trophozoite adherence to human collagen type I The BG-3 strain showed low collagenolytic activity and a low capacity to produce liver lesions in the hamster model, as compared with the parenteral strain HM1:IMSS (Flores-Romo et al 1997;Serrano et al 1994Serrano et al , 1996. This observation encouraged us to quantify the adherence of both strains to human collagen type I.…”

Entamoeba lysyl-tRNA Synthetase Contains a Cytokine-Like Domain with Chemokine Activity towards Human Endothelial Cells

“…ALA formation starts with the interaction of Entamoeba trophozoites with liver endothelial cells [6] that triggers cytokine production and the recruitment of neutrophils and macrophages around each individual parasite, forming a granuloma [7], [8]. This immune response causes acute inflammation and massive trophozoite killing [9], while surviving amoebae divide causing abscesses [10].…”

Phenotypic and transcriptional profiling in Entamoeba histolytica reveal costs to fitness and adaptive responses associated with metronidazole resistance

“…In E. histolytica , establishment and outcome of infection depend heavily on adhesive and invasive capacity (Flores-Romo et al, 1997 ). Recently, drug resistance has been shown to modulate these factors and vice versa (Giha et al, 2006 ).…”