B7-1/B7-H1相对比例变化对Hsp70-肽复合物抗肿瘤免疫效应的影响

目的：探讨Hsp7肽复合物对B7-1／B7-H1相对比例的影响及真核表达可溶性PD-1(sPD-1)对Hsp70-肽复合物抗肿瘤作用的影响。方法：通过RT-PCR和半定量PCR技术检测Hsp70-肽复合物体外刺激和体内免疫对小鼠脾细胞正调控共刺激分子B7-1和抑制性共刺激分子B7-H1及其受体PD-1表达的影响；体内转染表达sPD-1后，观察Hsp70-肽复合物免疫小鼠的肿瘤生长以及脾淋巴细胞毒性的变化。结果：基因表达检测表明．Hsp70-肽复合物体外刺激的小鼠脾细胞B7-1 mRNA和B7-H1 mRNA的水平随时问而变化，B7-1／B7-H1比值随刺激时间而增高；Hsp70-肽复合物体内免疫小鼠后期脾细胞B7-1表达下降，B7-H1及其受体PD-1表达上调，B7-1／B7-H1比值逆转；体内表达sPD-1可显著增强和延长Hsp70-肽复合物的抑瘤效果；体内表达sPD-1可提高Hsp70-肽复合物免疫的荷瘤小鼠脾细胞的杀伤率。结论：Hsp70-肽复合物的刺激引起共刺激分子B7-1和B7-H1表达的变化，B7-1／B7-H1的比例与激活效应相关，sPD-1通过阻抑B7-H1／PD-1途径、上调B7-1／B7-H1比例，可增强免疫应答，提高Hsp70-肽复合物特异性免疫治疗肿瘤的效应。     

卵巢浆液性腺癌肿瘤微环境中CD8~+TILs密度及PD-L1的表达与临床意义

目的:研究卵巢浆液性腺癌肿瘤微环境中CD8~+肿瘤浸润淋巴细胞(TILs)密度及癌细胞程序性死亡配体-1(PD-L1)的表达情况与临床意义。方法:收集2004年7月至2010年12月于上海交通大学医学院附属仁济医院行肿瘤细胞减灭术的116例卵巢浆液性腺癌患者组织标本,免疫组化检测肿瘤组织CD8~+TILs密度及癌细胞PD-L1表达情况;Spearman相关性分析癌细胞PD-L1表达水平与癌巢及间质CD8~+TILs数目的关系;采用乘积极限法进行基于癌巢CD8~+TILs密度及肿瘤细胞PD-L1表达的单因素生存分析。结果:卵巢浆液性腺癌PD-L1高表达的比例为70.69%(82/116)。癌细胞PD-L1表达强度与癌巢内的CD8~+TILs数目呈显著负相关(P=0.024),而与间质内的CD8~+TILs数目无相关性(P=0.117)。癌巢CD8~+TILs高密度组患者的中位生存时间(64月)显著高于低密度组(43月),差异有统计学意义(P0.05);乘积极限法的亚组分析显示肿瘤微环境中癌细胞PD-L1低表达癌巢CD8~+TILs高密度组患者的预后较好。结论:卵巢浆液性腺癌肿瘤微环境中癌巢CD8~+TILs密度及癌细胞PD-L1表达水平与患者预后密切相关,重视肿瘤微环境的免疫分型有助于评估患者预后及筛选合适患者实施抗PD-1/PD-L1免疫治疗。     

Caspases-3, -8, and -9 are required for induction of epithelial cell apoptosis by enteropathogenic E. coli but are dispensable for increased paracellular permeability

Enteropathogenic Escherichia coli (EPEC) is an important cause of diarrhea, particularly among infants in developing countries. An increase in intestinal permeability due to EPEC infection has been suggested as a factor in the development of diarrhea. Abnormally high levels of programmed cell death (apoptosis) of intestinal epithelial cells can lead to increased intestinal permeability. The effects of EPEC on cell apoptosis remain incompletely understood. This study characterized the mechanisms of EPEC-induced epithelial apoptosis and examined whether this effect contributes to heightened permeability in an in vitro model of infection. We report that EPEC-induced apoptosis in T84 intestinal epithelial cells via a mechanism involving caspases-3, -6, -8, and -9, the cleavage of PARP, and oligonucleosome formation. In addition, EPEC time-dependently increased paracellular permeability as assessed by transepithelial resistance and the apical-to-basolateral movement of 3000 MW dextran. Furthermore, EPEC infection led to the cleavage and mislocalization of tight junctional ZO-1 and occludin. However, pharmacological inhibition of caspases did not prevent the EPEC-induced disruptions in epithelial barrier structure and function. Taken together, these results suggest that a caspase-dependent upregulation in epithelial cell apoptosis during EPEC infection occurs independent of impaired intestinal barrier function.     

叶酸修饰的聚乙烯亚胺聚合物载PD-L1 siRNA体外靶向胃癌细胞的研究

目的:构建高效的siRNA纳米载体靶向SGC-7901胃癌细胞,并下调胃癌表达的程序性死亡配体1(PD-L1)。方法:检测叶酸(FA)-PEG-SS-PEI-SPION纳米载体与siRNA复合后的粒径、电位等表征;体外实验检验siRNA的结合能力、复合物细胞毒性、细胞摄入能力及转染效率;磁共振(MR)成像检测示踪能力;检验胃癌细胞PD-L1下调效应及共培养T细胞的细胞因子水平。结果:N/P比值为10时,FA-PEG-SS-PEI-SPION完全复合siRNA,形成电位为(9.14±0.80)m V、粒径为(116.7±2.5)nm的多聚复合物。靶向组的转染率为(95.06±0.44)%,与非靶向组的(93.87±1.05)%相当;平均荧光强度为1 892.67±81.51,高于非靶向组的1 324.33±186.58(P0.05)。普鲁士蓝染色和激光共聚焦显微镜成像证实了复合物的细胞摄入。体外MR成像验证了聚合物的MR造影成像能力。靶向组PD-L1的mRNA最低相对表达量为9.07%±0.79%,Western blot显示PD-L1的表达显著降低。共培养实验显示IFN-γ和TNF-α的分泌水平增加,IL-10的分泌水平降低(P0.05)。结论:本研究构建了FA-PEG-SS-PEI-SPION纳米载体,并证明了其体外靶向细胞及载siRNA下调PD-L1表达的能力和MR示踪的能力,是一种高效和安全的靶向治疗纳米载体。     

Exogenous heat shock protein 27 uniquely blocks differentiation of monocytes to dendritic cells

Circulating heat shock protein (HSP)-27 is associated with tumor progression and increased post-injury infection. Extracellular HSP-27 might alter monocyte (MO)-derived DC and/or MPhi function to mediate immunosuppression. HSP-27 treatment inhibited expression of CD1a and CD1b/c, antigen uptake, and allogeneic T cell induction (MLR) by IL-4 + GM-CSF-differentiated human DC while increasing some MPhi characteristics ( upward arrowCD14, upward arrowCD16, upward arrowCD163). MO cytokine receptor profiles elicited by 24-h exogenous HSP-27 treatment remained supportive of immature DC (iDC) emergence ( upward arrowIL-4R, downward arrowIL-6R, downward arrowM-CSFR). IL-10, IL-6, and M-CSF (which promote MPhi differentiation) were significantly increased in IL-4 + GM-CSF + HSP-27 MO-->iDC differentiation cultures. However, HSP-27 treatment during MO differentiation to DC increased programmed cell death ligand 1 coinhibitor and depressed CD86 costimulator expression in parallel to decreased iDC MLR activity. This suggested that increased MPhi differentiation was not solely responsible for HSP-27 reduction of differentiating DC activity. HSP-27 treatment actually depressed the phagocytic capacity of MO differentiated to MPhi by IL-10 or M-CSF culture. CD163 (hemoglobin receptor) expression was depressed on M-CSF + HSP-27 MO-derived MPhi. HSP-27-mediated inhibition of MO-->iDC differentiation was reversed by p38alpha & beta inhibitor (SB202190) addition or TLR4 receptor modulation. HSP-27 impaired appropriate MO-->iDC and MO-->MPhi differentiation modulating expression of receptors necessary for their proper functions. This suggests that endogenous HSP-27 has immunoregulatory activities which could contribute to immunopathology.     

人外周血T淋巴细胞自噬现象的观察

目的：观察分离培养的人外周血T淋巴细胞的自噬现象。方法：密度梯度离心法及尼龙棉柱法分离健康成年人外周血T淋巴细胞，分空白组及地塞米松（DXM）组，培养72小时后观察细胞光镜及电镜形态学、MDC荧光染色，并用流式细胞仪检测自噬细胞比例变化。结果：①通过自然培养后人外周血T淋巴细胞可出现典型自噬细胞形态学改变。②空白组及DXM组72小时自噬细胞发生率与0小时比较有显著性差异。③DXM组与空白组72小时自噬细胞发生率有显著性差异。结论：人外周血T淋巴细胞存在自噬现象，DXM可诱导人外周血T淋巴细胞自噬。     

VX-induced cell death involves activation of caspase-3 in cultured rat cortical neurons

Exposure of cell cultures to organophosphorous compounds such as VX can result in cell death. However, it is not clear whether VX-induced cell death is necrotic or involves programmed cell death mechanisms. Activation of caspases, a family of cysteine proteases, is often involved in cell death, and in particular, caspase-3 activation appears to be a key event in programmed cell death processes including apoptosis. In this study, we investigated VX-induced neuronal cell death, as well as the underlying mechanism in terms of its effect on caspase-3 activity. Primary cortical neuronal cultures were prepared from gestational days 17 to 19 Sprague Dawley rat fetuses. At maturation, the cells were treated with varying concentrations of VX and cell death was evaluated by lactate dehydrogenase (LDH) release. VX induced an increase in LDH release in a concentration-dependent manner. Morphological VX-induced cell death was also characterized by using nuclear staining with propidium iodide and Hoechst 33342. VX induced a concentration- and time-dependent increase in caspase-3 activation. Caspase-3 activation was also confirmed by the proteolytic cleavage of poly(ADP-ribose)polymerase (PARP), an endogenous caspase-3 substrate. These data suggested that in rat cortical neurons, VX-induced cell death via a programmed cell death pathway that involves changes in caspase-3 protease.     

程序性死亡分子1及其配体1在尖锐湿疣患者外周血T淋巴细胞的表达及意义

目的：研究程序性死亡分子1（PD?1）及其配体1（PD?L1）在尖锐湿疣患者外周血T淋巴细胞表面的表达,探讨PD?1/PD?L1信号通路在尖锐湿疣患者细胞免疫中的作用。方法采用流式细胞仪检测30例尖锐湿疣患者和20例健康对照者外周血CD4+、CD8+T淋巴细胞表面PD?1、PD?L1的表达及CD4+、CD8+T淋巴细胞计数,采用双抗体夹心酶联免疫吸附测定法检测血清中白细胞介素2（IL?2）,干扰素γ（IFN?γ）的水平,比较两组间的差异,分析尖锐湿疣患者外周血T淋巴细胞表面PD?1、PD?L1表达水平与CD4+、CD8+T淋巴细胞计数、细胞因子IL?2、IFN?γ的相关性。结果尖锐湿疣组CD4+、CD8+T淋巴细胞PD?1表达水平（分别为9.48%±3.31%和12.52%±3.17%）、PD?L1表达水平（4.40%±1.46%、7.07%±2.23%）分别高于健康对照组（PD?1：7.12%±2.16%、9.95%±2.17%,t=2.81、3.16,均P<0.01;PD?L1：3.26%±1.13%、5.39%±1.69%,t=2.96、2.88,均P<0.01）。尖锐湿疣组CD4+T淋巴细胞计数（727.43±138.59个/μl）低于对照组（804.25±92.83个/μl,t=2.17,P<0.05）, CD8+T淋巴细胞计数与对照组差异无统计学意义（t=1.24,P>0.05）,CD4+/CD8+比值（1.23±0.35）低于对照组（1.46±0.34,t=2.24,P<0.05）。尖锐湿疣组血清IL?2、IFN?γ水平均低于对照组（t=2.12、2.16,均P<0.05）。相关分析显示,尖锐湿疣患者外周血CD4+T淋巴细胞表面PD?1、PD?L1表达水平分别与CD4+T淋巴细胞计数、CD4+/CD8+比值、IL?2、IFN?γ水平均呈负相关（P<0.05）;CD8+T淋巴细胞表面PD?1、PD?L1表达水平与CD4+/CD8+比值均呈负相关（P<0.05）,与CD8+T淋巴细胞计数无相关性（P>0.05）。结论尖锐湿疣患者外周血T淋巴细胞高表达的PD?1可能通过与其配体PD?L1作用形成PD?1/PD?L1信号通路,抑制T淋巴细胞免疫应答,导致尖锐湿疣患者CD4+T淋巴细胞数量减少,CD4+/CD8+比值下降,IL?2、IFN?γ减少。