Gallardo-Vera Francisco, Diaz Daniel, Tapia-Rodriguez Miguel, Fortoul van der Goes Teresa, Masso Felipe, Rendon-Huerta Erika, Montaño Luis F
a Laboratorio Inmunobiología, Departamento de Biología Celular y Tisular, Facultad de Medicina .
b Departamento de Biología Celular y Fisiología .
J Immunotoxicol. 2016;13(1):27-37. doi: 10.3109/1547691X.2014.996681. Epub 2015 Jan 7.
Vanadium is a major air pollutant with toxic and carcinogenic effects; it also exercises immunosuppressive effects on the adaptive immune response. Its effect on the innate immune response is poorly explored. The aim of this study was to identify if vanadium pentoxide (V2O5) impairs the function of immunoregulatory NK cells and to determine possible mechanisms associated with this effect. Interleukin-2-independent NK-92MI cells were exposed to different V2O5 concentrations for 6, 12, or 24 h periods. Cell proliferation was then evaluated using CFSE staining, apoptosis by Annexin V binding, and necrosis by 7-AAD staining. The release of IL-2, -4, -6, -10, -17A, IFNγ, and TNFα by the cells were assessed using a human CBA kit. Expression of CD45, SOCS1, JAK3, pJAK3, STAT5, pSTAT5, IL-2R, IL-15R, Fas, and FasL in/on the cells was determined by flow cytometry; JAK3 and pJAK3 expression were also evaluated via confocal microscopy. The results indicated that V2O5 could inhibit NK-92MI cell proliferation and induce cell apoptosis in a dose- and time-related manner. V2O5 also inhibited IL-2, IL-10, and IFNγ secretion but mostly only after 24 h of exposure and with primarily the higher doses tested. V2O5 had no effect on expression of JAK3 and STAT5, but did cause an increase in pJAK3 and appeared to lead (trend) to reductions in levels of phosphorylated STAT5. V2O5 increased the expression of IL-2R, IL-15R, Fas, and FasL at concentrations above the 50-100 µM range. V2O5 had no effect on expression of the CD45 membrane phosphatase, but it did cause an increase in the expression of SOCS1. These results indicate that a key toxic effect of V2O5 on NK cells is a dysregulation of signaling pathways mediated by IL-2. These effects could help to explain the previously-reported deleterious effects on innate immune responses of hosts exposed to inhaled V2O5.
钒是一种具有毒性和致癌作用的主要空气污染物；它还对适应性免疫反应具有免疫抑制作用。其对先天性免疫反应的影响尚未得到充分研究。本研究的目的是确定五氧化二钒（V2O5）是否会损害免疫调节性NK细胞的功能，并确定与此效应相关的可能机制。将不依赖白细胞介素-2的NK-92MI细胞暴露于不同浓度的V2O5中6、12或24小时。然后使用CFSE染色评估细胞增殖，通过膜联蛋白V结合评估细胞凋亡，通过7-AAD染色评估细胞坏死。使用人CBA试剂盒评估细胞释放的IL-2、-4、-6、-10、-17A、IFNγ和TNFα。通过流式细胞术测定细胞中/细胞上CD45、SOCS1、JAK3、pJAK3、STAT5、pSTAT5、IL-2R、IL-15R、Fas和FasL的表达；JAK3和pJAK3的表达也通过共聚焦显微镜进行评估。结果表明，V2O5可抑制NK-92MI细胞增殖并以剂量和时间相关的方式诱导细胞凋亡。V2O5还抑制IL-2、IL-10和IFNγ的分泌，但主要仅在暴露24小时后且主要是在测试的较高剂量下。V2O5对JAK3和STAT5的表达没有影响，但确实导致pJAK3增加，并且似乎导致（趋势）磷酸化STAT5水平降低。在浓度高于50-100µM范围时，V2O5增加了IL-2R、IL-15R、Fas和FasL的表达。V2O5对CD45膜磷酸酶的表达没有影响，但确实导致SOCS1的表达增加。这些结果表明，V2O5对NK细胞的关键毒性作用是由IL-2介导的信号通路失调。这些效应有助于解释先前报道的吸入V2O5对宿主先天性免疫反应的有害影响。
