Winsor D K, Ashkenazi S, Chiovetti R, Cleary T G
Department of Microbiology and Molecular Genetics, University of Texas Medical School, Houston 77030.
Infect Immun. 1992 Apr;60(4):1613-7. doi: 10.1128/iai.60.4.1613-1617.1992.
Enterohemorrhagic Escherichia coli (EHEC) produce Shiga-like toxins and attach to certain tissue culture cells. T84 cells are human colonic carcinoma cells. Unlike previously studied cell lines, T84 cells grown on collagen-coated surfaces polarize and produce tight junctions and desmosomes, forming a colonic epithelial cell layer in vitro. The purpose of this study was to examine the attachment of EHEC strains to the T84 cell line as a possibly more relevant in vitro model of EHEC adherence. Twelve EHEC strains were grown overnight in Penassay broth, suspended in minimal essential medium with and without 0.5% mannose, and incubated for 1 to 3 h with 5- to 7-day-old T84 cell monolayers grown on collagen-coated coverslips. The bacteria were removed, and attachment was quantitated microscopically. For both E. coli O157:H7 and other EHEC serotypes, there were marked differences in adherence between strains (range of 152 to 3 bacteria per oil immersion field). Mannose partially inhibited the adherence of some EHEC strains. Adherence to the T84 cells appeared to be related to the amount of pili present and not to the serotype. Electron micrographs showed that a highly adherent strain (strain 43-12) tended to form microcolonies in the area of tight junctions on the T84 cell monolayers. In addition, the attachment of these EHEC strains to T84 cells correlated with their ability to adhere to isolated rabbit colonocytes (r = 0.91, P = 0.00004; without mannose) (r = 0.60, P = 0.04; with mannose). These data show that there are EHEC strain-related differences in adherence which can be demonstrated in a human-derived colonic epithelial cell line (T84) and that these cells can be used to study EHEC adherence.
肠出血性大肠杆菌（EHEC）产生志贺样毒素并附着于某些组织培养细胞。T84细胞是人类结肠癌细胞。与先前研究的细胞系不同，在胶原包被表面生长的T84细胞会极化并产生紧密连接和桥粒，在体外形成结肠上皮细胞层。本研究的目的是检查EHEC菌株对T84细胞系的附着情况，作为EHEC黏附可能更相关的体外模型。12株EHEC菌株在Penassay肉汤中过夜培养，悬浮于含有和不含有0.5%甘露糖的最低必需培养基中，并与在胶原包被盖玻片上生长5至7天的T84细胞单层孵育1至3小时。去除细菌后，通过显微镜对附着情况进行定量。对于大肠杆菌O157:H7和其他EHEC血清型，菌株之间的黏附存在显著差异（每个油镜视野中细菌数量范围为152至3个）。甘露糖部分抑制了一些EHEC菌株的黏附。对T84细胞的黏附似乎与菌毛的数量有关，而与血清型无关。电子显微镜照片显示，一株高黏附性菌株（43 - 12株）倾向于在T84细胞单层的紧密连接区域形成微菌落。此外，这些EHEC菌株对T84细胞的附着与其黏附分离的兔结肠细胞的能力相关（无甘露糖时r = 0.91，P = 0.00004；有甘露糖时r = 0.60，P = 0.04）。这些数据表明，在黏附方面存在与EHEC菌株相关的差异，这可以在人源结肠上皮细胞系（T84）中得到证明，并且这些细胞可用于研究EHEC的黏附。
