Korean J Gastroenterol.  1997 Aug;30(2):194-203.

Effects of Contact Inhibitionof Entamoeba histolytica Trophozoites to Human Colon Epithelial Cells in Proinflammatory Cytokine Gene Expression in Colon Epithelial Cells Induced by E.histolytica

• Kim JM
• Jung HC
• Lee KM
• Chin YJ
• Kim YJ
• Song IS
• Kim CY

Abstract

BACKGROUND AND AIMS: Entamoeba histolytica can cause invasive disease by clisruption of the intestinal barriers and subsequent lysis of the intestinal cells. Adherence to and contact-dependent killing of host cells requires the galactose-inhibitable lectin. To elucidate the mechanism whereby E. histolytica intluence on the host defence, we assessed the change of proinflammatory cytokine genes expressed by colon epithelial cells in response to co-culture with E. histolytica trophozoites and carbohydrates which prevent E. histolytica frorn attaching to epithelial cells.
METHODS
After HT-29 human colon epithelial cells were co-cultured with E. histolytica trophozoites in the presence or absence of carbohydrates including galactose, n-acetyl- galactosarnine or n-acetyl- lactosamine, RNA was extracted from the epithelial cells by an acid guanidinium thiocyanate- phenol-chloroform method. Cytokine gene expression was asse.sed by quantitative RT-PCR using the synthetic internal standard and the proteins were also determined by ELISA.
RESULTS
IL-8 mRNA expressed by HT-29 cells in response to E. histolytica trophozoites was downregulated in the presence of galactose, n-acetyl-galactosamine or n-acetyl-lactosamine, and this was paralleled by decreased IL-8 protein secretion. GM-CSF and IL-la mRNAs were also dc>wn- regulated in those cells in the presence of the agents.
CONCLUSIONS
These results suggest that the expression of proinflamrnatory cytokine genes could be inhibited by preventing E. histolyti ""a from attaching to the hosts colon epithelial cells.

Keyword

Entamoeba histolytica; Colon; Cytokine; Contact inhibition; Quaniitative RT-PCR

MeSH Terms

Carbohydrates
Coculture Techniques
Colon*
Contact Inhibition
Entamoeba histolytica*
Entamoeba*
Enzyme-Linked Immunosorbent Assay
Epithelial Cells*
Galactose
Gene Expression*
Granulocyte-Macrophage Colony-Stimulating Factor
Guanidine
Homicide
HT29 Cells
Humans*
Interleukin-8
RNA
RNA, Messenger
Trophozoites*
Carbohydrates
Galactose
Granulocyte-Macrophage Colony-Stimulating Factor
Guanidine
Interleukin-8
RNA
RNA, Messenger