牙周致病菌免疫逃逸机制的研究进展

牙周致病菌可引起牙周组织慢性炎症,由其引发的宿主过度的免疫炎症反应会进一步加重牙周组织的损伤。本文就龈沟的天然免疫防御机制,微生物对龈沟防御机制的敏感性,中性粒细胞和牙龈上皮细胞对牙周致病菌的免疫反应进行系统阐述,旨在表明真正的牙周致病菌因不能很好地激发或者抑制宿主的免疫反应,从而逃避宿主的免疫防御,导致牙周炎的发生,为牙周病的治疗和早期预防提供参考依据。     

Development of large-scale manufacturing of adipose-derived stromal cells for clinical applications using bioreactors and human platelet lysate

In vitro expanded adipose-derived stromal cells (ASCs) are a useful resource for tissue regeneration. Translation of small-scale autologous cell production into a large-scale, allogeneic production process for clinical applications necessitates well-chosen raw materials and cell culture platform. We compare the use of clinical-grade human platelet lysate (hPL) and fetal bovine serum (FBS) as growth supplements for ASC expansion in the automated, closed hollow fibre quantum cell expansion system (bioreactor). Stromal vascular fractions were isolated from human subcutaneous abdominal fat. In average, 95?×?10⁶ cells were suspended in 10% FBS or 5% hPL medium, and loaded into a bioreactor coated with cryoprecipitate. ASCs (P0) were harvested, and 30?×?10⁶ ASCs were reloaded for continued expansion (P1). Feeding rate and time of harvest was guided by metabolic monitoring. Viability, sterility, purity, differentiation capacity, and genomic stability of ASCs P1 were determined. Cultivation of SVF in hPL medium for in average nine days, yielded 546?×?10⁶ ASCs compared to 111?×?10⁶ ASCs, after 17?days in FBS medium. ASCs P1 yields were in average 605?×?10⁶ ASCs (PD [population doublings]: 4.65) after six days in hPL medium, compared to 119?×?10⁶ ASCs (PD: 2.45) in FBS medium, after 21?days. ASCs fulfilled ISCT criteria and demonstrated genomic stability and sterility. The use of hPL as a growth supplement for ASCs expansion in the quantum cell expansion system provides an efficient expansion process compared to the use of FBS, while maintaining cell quality appropriate for clinical use. The described process is an obvious choice for manufacturing of large-scale allogeneic ASC products.     

血小板对胃癌间质干细胞生物学特性的影响

目的观察血小板对胃癌间质干细胞(gastric cancer mesenchymal stem cells,GC-MSCs)的生物学特性以及对GC-MSCs促进肿瘤细胞迁移能力的影响。方法从健康志愿者静脉血标本中分离血小板;体外分离培养人GC-MSCs并分为对照组和GC-MSCs+血小板组,用流式细胞术检测GC-MSCs的细胞表型;成脂、成骨实验检测GC-MSCs的成脂、成骨能力;细胞计数法和Transwell实验检测GC-MSCs的增殖和迁移能力;将GC-MSCs与血小板或肿瘤细胞上清处理后的血小板共培养,western blot检测α-SMA蛋白的表达水平;将SGC-7901与GC-MSCs的细胞培养上清和血小板处理后的GC-MSCs上清共培养,Transwell实验检测SGC-7901的迁移能力。结果 GC-MSCs+血小板组的成脂、成骨能力增强,且增殖能力(24 h,t=3.88,P0.05; 48 h,t=5.93,P0.05; 72 h,t=4.35,P0.05)和迁移能力(t=4.03,P0.05)也明显加强; SGC-7901上清处理血小板组与单独血小板组的α-SMA蛋白表达水平高于对照组; SGC-7901与GC-MSCs上清或血小板处理后的GC-MSCs上清共培养后,其迁移能力增强(F=42.92,P0.05)。结论血小板可促进GC-MSCs增殖、迁移及成脂、成骨分化能力,并且可增强GC-MSCs促进肿瘤细胞迁移的能力。     

血小板增强骨髓间充质干细胞促肿瘤转移作用

目的观察血小板作用于人骨髓间充质干细胞(mesenchymal stem cells,MSCs)后对肿瘤细胞转移的作用。方法体外分离培养人骨髓MSCs及健康人外周血中的血小板;实验分为MSCs组、血小板+MSCs组及肿瘤细胞上清处理血小板+MSCs组(T-血小板+MSCs),分别收集3组培养24 h后的MSCs及培养上清(SGC-7901-CM及MSCs-CM);western blot检测其肿瘤相关成纤维母细胞(CAF)标志蛋白α-SMA及Vimentin的表达;Transwell实验检测骨髓MSCs的迁移能力;流式细胞术检测SGC-7901-CM及MSCs-CM共培养后血小板P选择素的表达水平;建立BALB/c裸鼠尾静脉注射SGC-7901胃癌细胞系转移模型,观察体内肿瘤转移情况。结果 SGC-7901-CM及MSCs-CM处理的血小板P选择素的表达水平[分别为(31.4±1.71)%、(21.37±1.00)%]明显高于对照组[(3.17±0.40)%],差异有统计学意义(t分别为27.85和29.18,P均0.01);血小板+MSCs组及T-血小板+MSCs组α-SMA蛋白[分别为(0.79±0.08)、(0.90±0.06)]及Vimentin蛋白[分别为(0.88±0.01)、(0.96±0.04)]的表达水平均明显高于MSCs组[分别为(0.64±0.02)、(0.75±0.05)],差异有统计学意义(t分别为2.96和6.45,4.73和5.73,P均0.01);血小板+MSCs组及T-血小板+MSCs组迁移细胞数[分别为(340.3±27.7)个、(424.3±17.6)个]明显高于MSCs组[(220.7±19.4)个],差异有统计学意义(t分别为6.14和13.48,P均0.01);体内实验结果表明,血小板+MSCs组转移灶及T-血小板+MSCs组转移灶[分别为(4±2)个、(21±4)个]明显高于MSCs组[(0.33±0.06)个],差异有统计学意义(t分别为3.051和8.857,P均0.01)。结论血小板能促进骨髓MSCs迁移,并能增强骨髓MSCs体内促进肿瘤细胞转移能力。