SgCypB介导淋巴管内皮细胞凋亡损伤引起孢子丝菌扩散机制的研究

孢子丝菌病是最常见危害大的深部真菌病，我国以球形孢子丝菌感染和淋巴管型为主，经淋巴管扩散机制不明。我们发现组织病理中淋巴管扩张破坏，淋巴内皮细胞表达亲环素锚着受体硫酸乙酰肝素蛋白多糖（HSPG），球形孢子丝菌测序发现富含淋巴内皮细胞损伤相关基因和亲环素家族基因，球形孢子丝菌和纯化亲环素B与巨噬细胞协同导致淋巴内皮细胞凋亡可被亲环素B抗体或CD147抗体阻断。据此假说环素B结合HSPG引起淋巴管真菌粘附侵袭扩散，结合CD147介导淋巴内皮细胞凋亡、炎症形成、淋巴管损伤和真菌扩散。课题拟采用siRNA、抗体阻断和高通量筛选等方法，评价和证实亲环素B结合HSPG和CD147激活下游NF-κB通路导致球形孢子丝菌经淋巴管扩散，筛选亲环素B特异性小分子抑制剂进行修饰验证，明确亲环素B介导淋巴内皮细胞凋亡损伤的真菌扩散模式，阐明淋巴管型孢子丝菌病发生机制，为寻找新分子诊断标记和药物靶点提供理论基础。

Sporotrichosis, a chonic or subchronic sufferring disease, is one of the most common subcutaneous mycosis. In China, the main etiological agent is Sporothrix globosa (S.globosa) and the primary clinical form is cutaneous lymphatic sporotrichosis, while the migration mechanism of S.globosa is still unknown. Histopathology obervations from tissue samples of patients and animal models showed expansion and damage of the lymph-vessels. In fact, lymphatic endothelial cells (LECs) could bind cyclophilin via heparan sulfate proteoglycan (HSPG). S.globosa was found rich in genes associated lymphatic damage and cyclophilin family by whole-genome sequencing. Besides, we also found that with the help of macrophages, both of S.globosa and purified cyclophilin B (CypB) could combine to LECs, and trigger the apoptosis of these cells, which could be inhibited by anti-CypB or anti-CD147. In consequence, we hypothesized that SgCypB could bind to HSPG on the surface of LECs so as to proliferate and invade through lymph-vessel, while the combination with CD147 could trigger LECs apoptosis, inflamation, lymphatic damage and fungal migration. In this project, methods of siRNA, antibodies block, and high-throughput screening would be used to value and explore the the combination of SgCypB and HSPG or CD 147 and trigger the following NF-κB pathway when S.globosa migrates in the lympah-vessel. In addition, it aims to select and verify sepcific small molecule inhibitor against SgCypB. This project would reveal the mechanism underlying the pattern that S.globosa damages LECs and spread in the lymphatic so as to elucidate the pathogenetic mechanism of cutaneous lymphatic sporotrichosis. Furthermore, the foundation would be layed for the further study of antifungal agents as well as molecular biomarkers for diagnosis.