Bacterium-assisted invasion of Entamoeba histolytica through human enteric epithelia in two-compartment chambers.
Entamoeba histolytica trophozoites initiate amebiasis by invasion into the enteric mucosa. It is the aim of our experiments to understand how bacteria and leukocytes act during amebic invasion through enteric cell layers. Cocultures were established in two-compartment chambers and studied by measurement of transepithelial electrical resistance (TER) and by histological examination. Trophozoites caused a decrease in TER that was followed by formation of holes in the enteric cell layer and transfilter migration of trophozoites. Phagocytosed bacteria activated trophozoites that opened the intracellular junctions and provided access for the invasion of bacteria. Leukocytes had no effect on the different steps of invasion of the trophozoites through the human enteric cell layers. We conclude that trophozoites, eventually assisted by enteric bacteria, disrupt enterocytic tight junctions before they open the enteric cell layer and invade through it.
Laboratory of Experimental Cancerology, University Hospital, University of Ghent, Belgium.
A
A
Leroy
G
G
De Bruyne
A
A
Verspeelt
T
T
Lauwaet
H
H
Nelis
M
M
Mareel
D000818:Animals; D018407:Bacterial Physiological Phenomena; D018929:Cell Culture Techniques / Q000379:methods; D002460:Cell Line; D018920:Coculture Techniques; D004404:Dysentery, Amebic / Q000382:microbiology / Q000469:parasitology; D004748:Entamoeba histolytica / Q000472:pathogenicity*; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology / Q000469:parasitology; D009504:Neutrophils / Q000276:immunology*