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目的:肺血管丛样病变是重度肺动脉高压(PAH)病人的特征病变,病变血管周围常伴有单个核细胞浸润。肺血管丛样病变在常用实验动物上难以复制,但可在肉鸡(一种生长快速的肉用型鸡)肺脏中自发形成。内皮祖细胞(EPCs)在组织再生和血管修复过程中发挥重要作用。本研究以肉鸡为模型,探讨EPCs与肺血管丛样病变形成之间的关系。创新点:证实EPCs参与了肺血管丛样病变的形成过程,并揭示了导致EPCs功能障碍的免疫学机制。方法:采集1~4周龄肉鸡肺组织,常规石蜡切片,观察肺血管丛样病变的形成情况;采用免疫组化法检测EPCs表面标志CD133和VEGFR-2的表达以及肝细胞生长因子(HGF)的表达;分离培养晚期EPCs,建立EPCs/淋巴细胞共培养体系,并在共培养体系中添加20 ng/ml HGF,观察EPCs增殖、凋亡和体外管样结构形成的变化。结论:在不同周龄的肉鸡肺组织中均可观察到处于不同发展阶段的肺血管丛样病变(图1)。早期的丛样病变主要由EPCs(CD133~+和VEGFR-2~+细胞)构成,HGF在病变实体中高表达(图2)。淋巴细胞共培养显著促进EPCs凋亡(图5),并能阻断HGF诱导的EPCs存活和体外管样结构形成(图6)。综上所述,肺血管丛样病变的形成可能与局部免疫炎症反应诱导EPCs凋亡并下调EPCs对促血管生成因子的反应性有关。

Mesenchymal stem cells （MSCs） have great potential for treating various diseases, especially those related to tissue damage involving immune reactions. Various studies have demonstrated that MSCs are strongly immunosuppressive in vitro and in vivo. Our recent studies have shown that un-stimulated MSCs are indeed incapable of immunosuppression; they become potently immunosuppressive upon stimulation with the supernatant of activated lymphocytes, or with combinations of IFN-γ, with TNF-α, IL-1α or IL-1β. This observation revealed that under certain circumstances, inflammatory cytokines can actually become immunosuppressive. We showed that there is a species variation in the mechanisms of MSC-mediated immunosuppression： immunosuppression by cytokine-primed mouse MSCs is mediated by nitric oxide （NO）, whereas immunosuppression by cytokine-primed human MSCs is executed through indoleamine 2, 3-dioxygenase （IDO）. Additionally, upon stimulation with the inflammatory cytokines, both mouse and human MSCs secrete several leukocyte chemokines that apparently serve to attract immune cells into the proximity with MSCs, where NO or IDO is predicted to be most active. Therefore, immunosuppression by inflammatory cytokine-stimulated MSCs occurs via the concerted action of chemokines and immune-inhibitory NO or IDO produced by MSCs. Thus, our results provide novel information about the mechanisms of MSC-mediated immunosuppression and for better application of MSCs in treating tissue injuries induced by immune responses.

Background： Vulvovaginal candidiasis is caused by Candida albicans. The vaginal epithelium, as the first site of the initial stage of infection by pathogens, plays an important role in resisting genital tract infections. Moreover, lactobacilli are predominant members of the vaginal microbiota that help to maintain a normal vaginal microenvironment. Therefore, Lactobacillus crispatus was explored for its capacity to intervene in the immune response of vaginal epithelial cells VK2/E6E7 to C. albicans. Methods： We examined the interleukin-2 （IL-2）, 4, 6, 8, and 17 produced by VK2/E6E7 cells infected with C. albicans and treated with L. crispatus in vitro. The capacity ofL. crispatus to adhere to VK2/E6E7 and inhibit C. albicans growth was also tested by scanning electron microscopy （SEM） and adhesion experiments. Results： Compared with group VK2/E6E7 with C. albicans, when treated with L. crispatus, the adhesion of C. albicans to VK2/E6E7 cells decreased significantly by 52.87 ± 1.22%, 47.03 ± 1.35%, and 42.20 ± 1.55% under competition, exclusion, and displacement conditions, respectively. SEM revealed that the invasion of C. albicans into VK2/E6E7 cells was caused by induced endocytosis and active penetration. L. crispatus could effectively protect the cells from the virulence ofhyphae and spores of C. albicans and enhance the local immune function of the VK2/E6E7 cells. The concentrations of IL-2, 6, and 17 were upregulated significantly （P 〈 0.0 1） and that of IL-8 were downregulated significantly （P 〈 0.0 1） in infected VK2/E6E7 cells treated with L. crispatus. The concentration of IL-4 was similar to that of the group VK2/ E6E7 with C. albicans （24.10 ± 0.97 vs. 23.12 ±0.76 pg/ml, P= 0.221）. Conclusions： L. crispatus can attenuate the virulence of C. albicans, modulate the secretion of cytokines and chemokines, and enhance the immune response of VK2/E6E7 cells in vitro. The vaginal mucosa has a potential function in the local immune responses against pathogens that can be promoted by L. crispatus.

Semaphorins were originally identified as axon guidance factors involved in the development of the neuronal system. However, accumulating evidence indicates that several members of semaphorins, so-called ＇immune semaphorins＇, are crucially involved in various phases of immune responses. These semaphorins regulate both immune cell interactions and immune cell trafficking during physiological and pathological immune responses. Here, we review the following two functional aspects of semaphorins and their receptors in immune responses： their functions in cell-cell interactions and their involvement in immune cell trafficking.

MicroRNAs （miRNAs） are small, non-coding single-stranded RNAs that can modulate target gene expression at post- transcriptional level and participate in cell proliferation, differentiation, and apoptosis. T cells have important functions in acquired immune response; miRNAs regulate this immune response by targeting the mRNAs of genes involved in T cell developmentp proliferationj differentiationp and function. For instancep miR-181 family members function in progression by targeting Bcl2 and CD69, among others. MiR-17 to miR-92 clusters function by binding to CREB 1, PTEN, and Bim. Considering that the suppression ofT cell-mediated immune responses against tumor cells is involved in cancer progression, we should investigate the mechanism by which miRNA regulates T cells to develop new approaches for cancer treatment.

In recent years, the technology of constructing chimeric mice with humanized immune systems has markedly improved. Multiple lineages of human immune cells develop in immunodeficient mice that have been transplanted with human hematopoietic stem cells. More importantly, these mice mount functional humoral and cellular immune responses upon immunization or microbial infection. Human immunodeficiency virus type I （HIV-1） can establish an infection in humanized mice, resulting in CD4＋ T-cell depletion and an accompanying nonspecific immune activation, which mimics the immunopathology in HIV-l-infected human patients. This makes humanized mice an optimal model for studying the mechanisms of HIV-1 immunopathogenesis and for developing novel immune-based therapies.

This study assessed and compared the immunogenicity of various immunization strategies in mice using combinations of re- combinant DNA （pCCMp24） and recombinant attenuated vaccinia virus Tian Tan （rddVTT_ccMpe4）. Intramuscular immuniza- tion was performed on days 0 （prime） and 21 （boost）. The immunogenicity of the vaccine schedules was determined by meas- uring human immunodeficiency virus （HIV）-specific binding antibody levels and cytokine （interleukin-2 and interleukin-4） concentrations in peripheral blood, analyzing lymphocyte proliferation capacity against HIV epitopes and CD4~/CD8＋cell ratio, and monitoring interferon-gamma levels at different times post-immunization. The results showed that pCCMp24, rddVTT.ccMp24 and their prime-boost immunization induced humoral and cellular immune responses. The pCCMp24/ rddVTT.ccMp24 immunization strategy increased CD8＋ T cells and induced more IFN-7-secreting cells compared with sin- gle-shot rDNA. The prime-boost immunization strategy also induced the generation of cellular immunological memory to HIV epitope peptides. These results demonstrated that prime-boost immunization with rDNA and rddVTT_ccMp24 had a tendency to induce greater cellular immune response than single-shot vaccinations, especially IFN-7 response, providing a basis for further studies.

The recognition of p-glucans by dectin-1 has been shown to mediate cell activation, cytokine production and a variety of antifungal responses. Here, we report that the functional activity of dectin-1 in mucosal immunity to Candida albicans is influenced by the genetic background of the host. Dectin-1 was required for the proper control of gastrointestinal and vaginal candidiasis in C57BIJ6, but not BALB/c mice; in fact, the latter showed increased resistance in the absence of dectin-1. The susceptibility of dectin-l-deficient C57BL/6 mice to infection was associated with defects in IL-17A and aryl hydrocarbon receptor-dependent IL-22 production and in adaptive Th I responses. In contrast, the resistance of dectin- 1-deficient BALB/c mice was associated with increased IL-17A and IL-22 production and the skewing towards Thl/Treg immune responses that provide immunological memory. Disparate canonical/ noncanonical NF-KB signaling pathways downstream of dectin-1 were activated in the two different mouse strains. Thus, the net activity of dectin-1 in antifungal mucosal immunity is dependent on the host＇s genetic background, which affects both the innate cytokine production and the adaptive Th1/Th17 cell activation upon dectin-1 signaling.

目的观察皮肤涂抹火箭煤油（RK）对小鼠细胞免疫的抑制作用。方法建立皮肤迟发超敏反应（DTH）模型,观察皮肤火箭煤油的涂抹剂量与其细胞免疫功能抑制作用之间的关系。阴性对照和阳性对照组ICR雌性小鼠背部涂抹丙酮,火箭煤油组涂抹特定剂量及一定次数的火箭煤油（低剂量：0.5ml/kg;中剂量：1ml/kg;高剂量：2ml/kg）,每组6只。通过测定耳肿胀度判定火箭煤油的免疫抑制作用。阳性对照组和各实验组采用1%二硝基氟苯（DNFB）致敏。1不同剂量RK染毒1次：分为阴性对照组、阳性对照组、火箭煤油低剂量组、火箭煤油中剂量组、火箭煤油高剂量组;2同一剂量RK不同染毒次数（1次/d,天数不同）：分为阴性对照组、阳性对照组、低剂量RK 1次染毒组、低剂量RK 2次染毒组、低剂量RK 3次染毒组、低剂量RK 4次染毒组、低剂量RK 5次染毒组;3不同剂量RK 5次染毒（1次/d,连续5d）：分为阴性对照组、阳性对照组、低剂量RK 5次染毒组、中剂量RK 5次染毒组、高剂量RK 5次染毒组。采用体外培养的淋巴细胞增殖活性实验等方法观察皮肤涂抹RK的细胞免疫抑制持续时间,MTT法观察刀豆蛋白A（Con A）诱导的淋巴细胞增殖活性,流式细胞仪检测外周血T淋巴细胞亚群（CD3＋、CD4＋和CD8＋）和脾淋巴细胞细胞周期。结果 RK 1次染毒能降低DNFB致敏引起的ICR小鼠耳肿胀、脾脏系数升高及胸腺指数降低（P〈0.05）,RK对小鼠的细胞免疫抑制作用随剂量与染毒次数的增加而增加。RK 1次染毒可以降低Con A诱导的脾淋巴细胞增殖且持续至染毒后20d仍有显著差异（P〈0.05）,染毒后第10天CD4＋/CD8＋比值显著降低。结论皮肤染毒RK对小鼠细胞免疫具有明显的抑制效应。

目的 探讨五味子甲素对胶质瘤干/祖细胞耐药性的影响及作用机制.方法 自人胶质瘤细胞系SHG-44中分离培养胶质瘤干/祖细胞SHG-44s,予五味子甲素0、12.50、25.00和50.00 μmol/L联合长春新碱400、800和1200 nmol/L,细胞活性检测试剂盒CCK-8细胞毒性实验检测SHG-44s细胞增殖活性,罗丹明123染色检测SHG-44s细胞泵出药物能力,实时聚合酶链反应(PCR)和Western blotting法检测SHG-44s细胞ATP结合盒转运子B1(ABCB1)基因转录和翻译能力.结果 五味子甲素50 μmol/L即可抑制SHG-44s细胞增殖活性(P=0.001,0.001,0.039),剔除这一浓度后无论长春新碱浓度为400、800或1200 nmol/L,联合应用五味子甲素均可抑制SHG-44s细胞增殖活性(长春新碱400 nmol/L组:P=0.007,0.001;长春新碱800 nmol/L组:P=0.001,0.000;长春新碱1200 nmol/L组:P=0.000,0.000).倒置荧光显微镜观察,五味子甲素12.50 μmol/L组和25.00 μmol/L组SHG-44s细胞可见明显绿色荧光.流式细胞术显示,随着五味子甲素浓度的增加,SHG-44s细胞罗丹明123染色阳性细胞比例分别为10.40％、39.20％和45.20％.实时PCR法显示,五味子甲素12.50μmol/L组和25.00μmol/L组SHG-44s细胞ABCB1基因表达水平较0μmol/L组降低(P=0.027,0.006),尤以25.00μmol/L组显著(P=0.034).Western blotting法显示,随着五味子甲素浓度的增加,SHG-44s细胞P-糖蛋白表达水平下降.结论 五味子甲素通过抑制胶质瘤干/祖细胞表面已存在的ABCB1基因编码的P-糖蛋白泵出药物能力并降低ABCB1基因转录和翻译能力,逆转胶质瘤干/祖细胞耐药性.