The stromal compartments in pancreatic cancer: Are there any therapeutic targets?

Pancreatic ductal adenocarcinoma (PDAC) is characterised by an abundant stromal response also known as a desmoplastic reaction. Pancreatic Stellate Cells have been identified as playing a key role in pancreatic cancer desmoplasia. There is accumulating evidence that the stroma contributes to tumour progression and to the low therapeutic response of PDAC patients. In this review we described the main actors of the desmoplastic reaction within PDAC and novel therapeutic approaches that are being tested to block the detrimental function of the stroma.     

调节性T细胞抑制约氏疟原虫感染小鼠早期Th1应答的建立

目的探讨调节性T细胞(Tregs)参与约氏疟原虫感染早期调控Th1型免疫应答的相关机制。方法用约氏疟原虫(致死型)感染对照组和anti-CD25 mAb注射组BALB/c小鼠,计数红细胞感染率;感染后第0、3和5d制备脾细胞悬液,磁珠分选、纯化树突状细胞(DCs)并体外培养;ELISA方法检测脾细胞培养上清中IFN-γ和DCs培养上清中IL-12的水平,Griess方法检测脾细胞培养上清中NO含量。结果两组小鼠脾细胞培养上清中IFN-γ和NO水平在感染后第3～5d均明显升高,但对照组小鼠IFN-γ和NO水平明显低于anti-CD25 mAb注射组小鼠。anti-CD25 mAb注射组小鼠DCs培养上清中IL-12的水平于感染后第3d达峰值,并于感染后第5d仍维持较高水平。相比,对照组小鼠DCs培养上清中IL-12的水平仅于感染后第3d出现有意义的升高。结论Tregs在致死型约氏疟原虫感染BALB/c小鼠早期可能通过抑制DCs分泌细胞因子IL-12来抑制Th1型免疫应答的有效建立。     

应用Dil标记的氧化高密度脂蛋白观察人单核细胞源性的树突状细胞成熟的研究

目的探讨氧化修饰高密度脂蛋白(OxHDL)和高密度脂蛋白(HDL)对人单核细胞源的树突状细胞(DCs)免疫功能的影响。方法从人外周血清中离心提取高密度脂蛋白,经氧化后,分别用Dil荧光标记。将人外周血分离的单核细胞加入包含rhGM-CSF(20ng/mL)和rhIL-4(20ng/mL)的培养基中培养,使其分化为DCs。以PBS作阴性对照,分别与50μg/mL的标记好的OxHDL和HDL混合培养48h后,动态观察DCs成熟过程中的形态学变化,流式细胞术检测DCs成熟表型(CD1#、CD80、CD86、HLA-DR)。结果使用Dil标记的方法良好地显示了DCs摄取OxHDL的形态学变化,OxHDL可促进DCs成熟表型HLA-DR、CD1$的表达(P<0.05),而HDL无此作用。结论Dil是适合DCs形态学研究的良好的荧光标记物,OxHDL可促进DCs成熟。     

Decreased interleukin(IL)-35 Expression is Associated with Active Intraocular Inflammation in Vogt-Koyanagi-Harada (VKH) Disease

Purpose: Recent studies have reported that IL-35 has a protective effect in autoimmune disease. In this study, we explored the role of IL-35 in the pathogenesis of Vogt-Koyanagi-Harada (VKH) disease.

Methods: The IL-35/EBI3 and IL-35/P35 mRNA level was assayed by Real-Time PCR. The level of IL-35 in serum was detected by ELISA. PBMCs and monocyte-derived DCs were cultured with or without IL-35 and the concentration of IL-17, IL-10, IFN-γ, IL-6, TNF-α, and IL-1β in supernatants was tested by ELISA.

Results: The serum level of IL-35 is reduced in active VKH patients. The mRNA expression of the two subunits IL-35/EBI3 and IL-35/P35 in PBMCs from patients with active VKH was also decreased. IL-35 significantly inhibited IFN-γ and IL-17 expression and induced IL-10 production by PBMCs and inhibited IL-6 production by monocyte-derived DCs.

Conclusion: The current study suggests that a decreased IL-35 expression may be involved in the pathogenesis of VKH disease.     

HL-60细胞凋亡小体体外负载树突状细胞的实验研究

目的 :证实树突状细胞 (Dendritic cells,DCs)可通过吞噬凋亡小体获取抗原物质 ,探讨其在肿瘤免疫治疗中的意义。方法 :利用吸附单克隆抗体 -磁珠分离系统 (MACS) ,从人脐血中分离出 CD34+ 细胞 ,体外以重组 h GM- CSF+ h SCF+ h TNF-α+ h FL诱导培养 DCs,光镜观察诱生细胞的形态 ,流式细胞术 (FACS)检测其表型。电镜观察和流式细胞仪检测三氧化二砷 (As2 O3 )诱导凋亡的 HL - 6 0细胞 ,将凋亡的 HL- 6 0细胞与培养早期的 DCs共育 4～ 8h,电镜观察 DCs吞噬凋亡小体的现象。结果 :CD34+细胞经诱生后生成了大量具有典型形态和表型的成熟 DCs;电镜下见凋亡的 HL- 6 0细胞内凋亡小体形成 ,流式细胞仪检测 DNA含量 ,见亚二倍体峰形成。凋亡细胞与 DCs共育后 ,电镜下见 DCs吞噬凋亡小体的现象。结论 :DCs可通过吞噬凋亡小体摄取抗原物质。     

Exploring the immunopotentiation of Chinese yam polysaccharide poly(lactic-co-glycolic acid) nanoparticles in an ovalbumin vaccine formulation in vivo

Biocompatible and biodegradable poly(lactic-co-glycolic acid) (PLGA) has been approved by the US Food and Drug Administration and has frequently been used to develop potential vaccine delivery systems. The immunoregulation and immunopotentiation of Chinese yam polysaccharide (CYP) have been widely demonstrated. In the current study, cell uptake mechanisms in dendritic cells (DCs) were monitored in vitro using confocal laser scanning microscopy, transmission electron microscopy, and flow cytometry. To study a CYP-PLGA nanoparticle-adjuvanted delivery system, CYP and ovalbumin (OVA) were encapsulated in PLGA nanoparticles (CYPPs) to act as a vaccine, and the formulation was tested in immunized mice. The CYPPs more easily underwent uptake by DCs in vitro, and CYPP/OVA could stimulate more effective antigen-specific immune responses than any of the single-component formulations in vivo. Mice immunized using CYPP/OVA exhibited more secretion of OVA-specific IgG antibodies, better proliferation, and higher cytokine secretion by splenocytes and significant activation of CD3⁺CD4⁺ and CD3⁺CD8⁺ T cells. Overall, the CYPP/OVA formulation produced a stronger humoral and cellular immune response and a mixed Th1/Th2 immune response with a greater Th1 bias in comparison with the other formulations. In conclusion, the data demonstrate that the CYPP-adjuvanted delivery system has the potential to strengthen immune responses and lay the foundation for novel adjuvant design.     

Adjuvant-active aqueous extracts from Artemisia rupestris L. improve immune responses through TLR4 signaling pathway

Activating innate immunity by an adjuvant is required in vaccine development. The study aims to investigate adjuvant effects of aqueous extracts of Artemisia rupestris L. (AEAR) in vivo and in vitro. ICR mice were subcutaneously administered with antigen and AEAR at various doses to evaluate their immune responses of antibodies, dendritic cells (DCs), regulatory T cells (Treg), splenic lymphocyte, and cytokine. The evaluation results showed that AEAR could largely increase titers of antigen-specific antibodies (IgG, IgG₁, and IgG_2a) and T cell proliferation. AEAR also increased expression of IFN-γ in CD8⁺T cells as well as IL-4 and INF-γ expression in CD4⁺T cells. Expression levels of MHC-II, CD40, CD80, and CD86 on DCs were significantly elevated, whereas the Treg frequency was significantly decreased. AEAR (200 μg) showed remarkable adjuvant activity. Furthermore, AEAR enhanced MHC-II, CD40, CD80, and CD86 expression as well as the yields of TNF-α and IL-12 on DCs through toll-like receptor4 (TLR4) in vitro. Those results indicated that AEAR could serve as an efficacious immune stimulator for vaccines because it significantly enhanced specific immune responses by promoting DCs maturation and reduced Treg through TLR4 signaling pathway.     

树突状细胞和PD-1/PD-L1通路相互作用的研究进展

树突状细胞（dendritic cells,DCs）是最强大的抗原呈递细胞,具有引起抗原特异性反应的能力,并且在调节免疫耐受中起重要作用。基于DCs的癌症免疫治疗已有二十多年的研究,是最重要的抗癌免疫疗法之一,但单一疗法在癌症治疗方面效果有限,需要继续深入研究以提高DCs的抗肿瘤作用,并寻找与其他方法协同治疗的方案。靶向于免疫检查点的单克隆抗体在公认的实体和血液恶性肿瘤的临床试验中均获得了成功,并在2018年获得诺贝尔医学奖。免疫检查点阻断疗法旨在解除肿瘤的免疫抑制以增强免疫系统的抗肿瘤作用,其中针对PD-1/PD-L1免疫检查点的阻断治疗已引起相当多的关注。虽然免疫检查点阻断治疗的效果令人鼓舞,但在尚未满足医疗需求的领域中仍需要进一步研究以提高临床效率。理论上DCs的PD-L1和/或T细胞的PD-1基因沉默或表达下调,可增强DCs启动有效的T细胞抗肿瘤反应。因此,将特异性DCs的抗肿瘤免疫治疗与PD-1/PD-L1信号通路阻断相结合的治疗方法是一个有希望的探索之路。本文主要综述DCs的功能、PD-1/PD-L1通路的抗肿瘤作用、DCs和PD-1/PD-L1信号通路相互作用在目前的研究现状以及前景。