PATHOGENESIS OF LYME NEUROBORRELIOSIS IN THE RHESUS MONKEY: STUDIES IN VITRO

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们和其他人推测炎症在莱姆病的发病机制中起作用。伯氏疏螺旋体（Borrelia burgdorferi，Bb）是导致莱姆病的细菌螺旋体，并且已知其诱导神经胶质细胞中炎症介质的产生。在Bb与从原代恒河猴皮层分离的小胶质细胞体外共培养的实验中，我们观察到炎性细胞因子/趋化因子IL-6和8、MIP-1 <$、MIP-1 <$、RANTES和MCP-1的稳健表达和释放，但我们没有检测到伴随的小胶质细胞凋亡诱导。与Bb单独共培养的SH-SY 5 Y（SY）神经元表达可忽略不计的炎症分子，并且对凋亡也具有高度抵抗性。相反，当小胶质细胞与SY细胞结合，然后与Bb共培养时，细胞凋亡的显著增加始终发生。共聚焦显微镜图像的混合培养物染色细胞凋亡的TUNEL法和细胞特异性标志物表明，它主要是神经元型细胞死亡的刺激与BB。 微阵列分析表明，除了小胶质细胞分泌的炎症介质在响应Bb，TLR 2和NFKB 1转录的表达增加也被观察到，并可能另外有助于神经毒性环境。总之，这些发现表明Bb对神经元没有直接毒性;相反，神经元通过旁观者效应在小胶质细胞产生的炎症环境中受损/死亡。这种神经元损伤可能最终导致神经疏螺旋体病中出现的神经认知症状。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We and others have postulated that inflammation plays a role in the pathogenesis of Lyme neuroborreliosis. Borrelia burgdorferi (Bb) is the bacterial spirochete that causes Lyme disease and is known to induce the production of inflammatory mediators in glial cells. In experiments where Bb was co-cultured in vitro with microglial cells isolated from primary rhesus cortex, we observed robust expression and release of the inflammatory cytokines/chemokines IL-6 and 8, MIP-1¿, MIP-1¿, RANTES and MCP-1 but we detected no concomitant induction of microglial apoptosis. SH-SY5Y (SY) neurons independently co-cultured with Bb expressed negligible amounts of inflammatory molecules and were also highly resistant to apoptosis. In contrast, when microglia were combined with SY cells and then co-cultivated with Bb, significant increases in apoptosis consistently occurred. Confocal microscopy images of the mixed cultures stained for apoptosis by the TUNEL assay and with cell specific markers suggested that it was predominantly the neuronal type cells that were dying in response to stimulation with Bb. Microarray analysis demonstrated that in addition to the inflammatory mediators secreted by microglia in response to Bb, increased expression of TLR2 and NFKB1 transcripts were also observed and may additionally contribute to a neurotoxic environment. Taken together, these findings indicate that Bb is not directly toxic to neurons; rather, neurons become impaired/die in the inflammatory surroundings generated by microglial cells through a bystander effect. This neuronal impairment may eventually contribute to the neurocognitive symptoms seen in neuroborreliosis.