Schulte R, Wattiau P, Hartland E L, Robins-Browne R M, Cornelis G R
Microbial Pathogenesis Unit, International Institute of Cellular and Molecular Pathology, Brussels, Belgium.
Infect Immun. 1996 Jun;64(6):2106-13. doi: 10.1128/iai.64.6.2106-2113.1996.
Epithelial cells of the intestinal mucosa are among the first cells encountered by invasive pathogens. Bacterial invasion of the mucosa gives rise to an inflammatory response, characterized by the influx of polymorphonuclear leukocytes. The chemotactic stimulus responsible for this accumulation is unknown, but several in vitro studies have demonstrated that epithelial cells secrete the chemokine interleukin-8 (IL-8), a potent chemoattractant of polymorphonuclear leukocytes, upon bacterial entry. In this study we analyzed the secretion of IL-8 by human intestinal (T84) and cervical (HeLa) epithelial cell lines in response to infection with the enteric pathogen Yersinia enterocolitica. IL-8 was secreted by T84 and HeLa cells in response to invasion by Y. enterocolitica. Virulent Y. enterocolitica induced a significantly lower level of IL-8 secretion than nonvirulent Y. enterocolitica. Subsequent analysis employing a mutant defective in Yop secretion and various yop mutants showed that the reduced secretion of IL-8 is due to the presence of Yop proteins. Our data suggest that YopB and YopD are required for the suppressive effect.
肠道黏膜上皮细胞是侵袭性病原体最先接触到的细胞之一。细菌对黏膜的侵袭会引发炎症反应，其特征为多形核白细胞的涌入。导致这种聚集的趋化刺激尚不清楚，但多项体外研究表明，细菌侵入时，上皮细胞会分泌趋化因子白细胞介素-8（IL-8），它是多形核白细胞的一种强效趋化剂。在本研究中，我们分析了人肠道（T84）和宫颈（HeLa）上皮细胞系在受到肠道病原体小肠结肠炎耶尔森菌感染时IL-8的分泌情况。T84和HeLa细胞在受到小肠结肠炎耶尔森菌侵袭时会分泌IL-8。有毒力的小肠结肠炎耶尔森菌诱导分泌的IL-8水平明显低于无毒力的小肠结肠炎耶尔森菌。随后使用Yop分泌缺陷突变体和各种yop突变体进行的分析表明，IL-8分泌减少是由于Yop蛋白的存在。我们的数据表明，YopB和YopD是产生抑制作用所必需的。
