灭活HIV-1颗粒引发小胶质细胞钙离子内流和NF-κB核转位的研究

Calcium influx and NF-κB translocation in microglia triggered by inactivated HIV-1 particles

目的:探讨灭活的1型人类免疫缺陷病毒颗粒(HIVp)对人小胶质细胞钙离子内流和转录因子NF-κB核转位的作用,对比不同亚型(HIVp-X4型与HIVp-R5型)的灭活HIVp所引发的钙离子内流强度差异。方法:将小胶质细胞接种到圆形盖玻片上,用钙离子探针Fluo-4进行染色,用共聚焦显微镜以荧光强度为指标实时观察不同刺激条件下细胞内钙离子水平的变化;联合胞内染色技术,用共聚焦显微镜记录不同处理条件下的小胶质细胞NF-κB核转位。结果:共聚焦显微镜检测结果显示HIVp所引发的钙内流效应明显强于gp120;在gp120同时存在的情况下,HIVp激发的钙离子内流效应会被其部分阻断;另外,HIVp-X4所引发的钙离子内流和NF-κB核转位要比HIVp-R5明显。结论:HIVp表面既有自身基因组编码的gp120蛋白,又有出胞时所携带的宿主蛋白,由于HIVp引发的钙内流效应明显强于gp120,因而推测HIVp表面的宿主蛋白在活化小胶质细胞中起了一定的协同作用;而HIVp-X4对小胶质细胞的刺激性明显强于HIVp-R5,提示X4型病毒是HIV相关性失智症的重要致病因素。

AIM： To explore the effects of inactivated human immunodeficiency voris type Ⅰ（HIV-1） particles on calcium influx and NF-κB translocation of human microglia, and to evaluate the different microglial responses to HIVp-X4 and HIVp-R5. METHODS： Microglia grown on round coverslip was loaded with calcium probe Fluo-4, and then its fluorescence intensity was recorded to compare the alteration of intracellular calcium concentration among different treated groups, such as gp120 versus HIVp and HIVp-X4 versus HIVp-R5, by confocal microscopy with time lapse mode. The translocation of NF-κB from cytoplasm to nucleus was detected by intracellular staining plus confocal microscopy. RESULTS： Compared with gp120, HIVp induced stronger calcium influx. Most interestingly, in the presence of gp120, calcium influx in microglia triggered by HIVp was partially blocked. Moreover, HIVp-X4 induced more robust calcium influx, as well as NF-κB activation, than HIVp-R5. CONCLUSION： Besides of self-encoding gp120, HIVp surface also incorporates host-derived proteins, which were thought to be potent accomplice of gp120 in triggering calcium influx since HIVp displayed stronger stimulation than gp120. Furthermore, the result that HIVp-X4 induced more robust calcium influx than HIVp-R5 indicated X4 virus was the most important factor in the pathogenesis of HIV associated dementia.