Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, United States of America.
PLoS One. 2012;7(6):e39633. doi: 10.1371/journal.pone.0039633. Epub 2012 Jun 22.
Endothelial cells are important in the pathogenesis of bloodstream infections caused by Candida albicans and Staphylococcus aureus. Numerous investigations have used human umbilical vein endothelial cells (HUVECs) to study microbial-endothelial cell interactions in vitro. However, the use of HUVECs requires a constant supply of umbilical cords, and there are significant donor-to-donor variations in these endothelial cells. The use of an immortalized endothelial cell line would obviate such difficulties. One candidate in this regard is HMEC-1, an immortalized human dermal microvascular endothelial cell line. To determine if HMEC-1 cells are suitable for studying the interactions of C. albicans and S. aureus with endothelial cells in vitro, we compared the interactions of these organisms with HMEC-1 cells and HUVECs. We found that wild-type C. albicans had significantly reduced adherence to and invasion of HMEC-1 cells as compared to HUVECs. Although wild-type S. aureus adhered to and invaded HMEC-1 cells similarly to HUVECs, an agr mutant strain had significantly reduced invasion of HMEC-1 cells, but not HUVECs. Furthermore, HMEC-1 cells were less susceptible to damage induced by C. albicans, but more susceptible to damage caused by S. aureus. In addition, HMEC-1 cells secreted very little IL-8 in response to infection with either organism, whereas infection of HUVECs induced substantial IL-8 secretion. This weak IL-8 response was likely due to the anatomic site from which HMEC-1 cells were obtained because infection of primary human dermal microvascular endothelial cells with C. albicans and S. aureus also induced little increase in IL-8 production above basal levels. Thus, C. albicans and S. aureus interact with HMEC-1 cells in a substantially different manner than with HUVECs, and data obtained with one type of endothelial cell cannot necessarily be extrapolated to other types.
内皮细胞在白色念珠菌和金黄色葡萄球菌引起的血流感染发病机制中起着重要作用。许多研究使用人脐静脉内皮细胞（HUVEC）在体外研究微生物-内皮细胞相互作用。然而，使用 HUVEC 需要脐带的持续供应，并且这些内皮细胞在供体之间存在显著的差异。使用永生化的内皮细胞系可以避免这些困难。在这方面的一个候选者是 HMEC-1，一种永生化的人真皮微血管内皮细胞系。为了确定 HMEC-1 细胞是否适合研究白色念珠菌和金黄色葡萄球菌与内皮细胞在体外的相互作用，我们比较了这些生物体与 HMEC-1 细胞和 HUVEC 的相互作用。我们发现，与 HUVEC 相比，野生型白色念珠菌对 HMEC-1 细胞的粘附和侵袭明显减少。虽然野生型金黄色葡萄球菌对 HMEC-1 细胞和 HUVEC 的粘附和侵袭相似，但 agr 突变株对 HMEC-1 细胞的侵袭明显减少，但对 HUVEC 细胞没有影响。此外，HMEC-1 细胞对白色念珠菌诱导的损伤的敏感性较低，但对金黄色葡萄球菌引起的损伤的敏感性较高。此外，HMEC-1 细胞对两种病原体感染的 IL-8 分泌反应较弱，而 HUVEC 感染则诱导大量的 IL-8 分泌。这种较弱的 IL-8 反应可能是由于 HMEC-1 细胞获得的解剖部位所致，因为白色念珠菌和金黄色葡萄球菌感染原代人真皮微血管内皮细胞也不会引起 IL-8 产生明显高于基础水平的增加。因此，白色念珠菌和金黄色葡萄球菌与 HMEC-1 细胞的相互作用方式与与 HUVEC 的相互作用方式有很大不同，并且从一种类型的内皮细胞获得的数据不一定可以推断到其他类型。
