病毒感染调控间充质干细胞生物学行为的研究

The infective product of virus regulates the biological behavior of mesenchymal stem cells

目的探讨病毒代谢产物是否影响间充质干细胞（mesenchymal stem cells，MSCs）的生物学行为，为MSCs移植安全性提供证据。方法分离纯化C57BL／6小鼠骨髓MSCs，检测其Toll样受体3（Toll like receptor3，TLR3）表达水平，采用poly（I：C）作为病毒代谢产物刺激MSCs，通过流式细胞术、PCR等技术检测MSCs自我更新、多向分化、定向迁移及免疫抑制功能的改变。结果①MSCs表达低水平TLR3，poly（I2C）刺激后其mRNA水平表达上调；（2）poly（I：C）分别刺激MSCs24、48及72h，其增殖能力与未刺激组MSCs相比差异无统计学意义（P〉0．05），但poly（I：C）却显著促进MSCs分化为成脂及成骨细胞（P〈0．01）；（3）poly（I：C）刺激MSCs后，其定向迁移能力明显减弱，6、12及24h其迁移率分别为未刺激组MSCs的（82．83±1．69）％、（87．80±3．58）％、（92．67±2．52）％，差异有统计学意义（P〈0．01）；④MSCs具有强大的免疫抑制功能，且具有MSCs数量依赖性，poly（I：C）刺激MSCs后其抑制脾脏淋巴细胞分裂增殖的能力并未受损，与对照组MSCs相比差异无统计学意义（P〉0．05）。结论在保证MSCs良好活性及免疫抑制功能的前提下，病毒代谢产物通过抑制MSCs迁移，使其在移植原位发挥保护移植物的功效，为MSCs作为种子细胞移植治疗糖尿病等免疫紊乱性疾病的安全性提供了证据。

Objective To study whether the viral metabolites can make influence on biological behavior of mesenchymal stem ceils（MSCs） and to provide evidence for safe MSCs transplantation. Methods MSCs were isolated from bone marrow of C57BL/6 mice and the mRNA level of Toll like receptor 3 （ TLR3 ） was detected. In vitro polyinosinic-polycytidylic acid[ poly（ I ： C） ] was used as the product of viral metabdite to stimulate MSCs. We recorded the change of MSCs in terms of self-renewal, multi-directional differentiation, directional migration and immunosuppression by flow cytometry, PCR etc. Results （1）Low-expressed TLR3 mRNA was dectected in MSCs and it was upregnlated after being stimulated by poly（I ： C）. （2）After being stimulated by poly（I ： C）for 24, 48, and 72 hours, the self-renewal ability of MSCs had no statistical difference with that of the control group（P 〉 0. 05 ）. However, poly（ I ： C）promoted the differentiation of MSCs to lipoblast and osteoblast（P 〈0. 01 ）. （3）The directional mi- gration ability of MSCs was weakened significantly by poly（I ： C） stimulation. After being stimulated for 6, 12, and 24 hours, the migration rate of MSCs was （82. 83 ± 1.69） %, （ 87. 80 ± 3.58 ） %, and （92. 67 ± 2. 52） % respectively com- pared to that of the control group. The difference had statistical significance（P 〈0. 01 ）. （4）MSCs had great immunologi- cal suppression ability and it was dependant on the number of MSCs. After being stimulated by poly（I ： C）, the ability of MSCs＇ immunological suppression on proliferation of activated splenocytes was not impaired and the difference had no statistical significance compared with that of the control group（P 〉0. 05）. Conclusion While maintaining the via- bility and immunosuppression function of MSCs, viral metabolite inhibits migration of MSCs, holds them in the transplanted position and protects the graft, providing evidence for MSCs as seed cells in the treatment of diabetes and other immune disorder diseases.