Cellular targets of regulatory B cell-mediated suppression

Regulatory B cells (Bregs) are defined by their ability to restrain inflammatory responses both in vivo and in vitro. Interleukin 10 (IL-10) production by Bregs is thought to be central to their ability to regulate inflammation, largely due to IL-10s’ ability to suppress pro-inflammatory cytokine production by effector lymphocytes and to maintain the differentiation of regulatory T cells (Tregs). However, with an increase in available published data, it has become evident that Bregs utilize a number of suppressive mechanisms in order to alter the activation of a variety of different lymphocytes. Here, we summarize the multiplicity of cellular targets of Breg-mediated suppression and describe the mechanisms employed by Bregs to suppress chronic inflammatory responses.     

Prognostic and clinicopathological utility of programmed death-ligand 1 in malignant pleural mesothelioma: A meta-analysis

ObjectiveProgrammed death ligand 1 (PD-L1) has been reported to be connected to prognosis in individuals with malignant pleural mesothelioma (MPM), although there is no consensus based on data from previous studies. Accordingly, this quantitative meta-analysis investigated prognostic and clinicopathological utility of PD-L1 in patients with MPM.MethodsA comprehensive search of the PubMed, Web of Science, Embase, and Cochrane Library databases for articles published up to October 4, 2019 was performed. Studies using immunohistochemical techniques to detect/quantify the expression of PD-L1 in MPM tissue were enrolled in the analysis. The combined hazard ratio (HR) and corresponding 95% confidence interval (CI) was applied to assess the association between PD-L1 expression and overall survival (OS).ResultsA total of 11 studies comprising 1606 patients was included in the present meta-analysis. For OS, pooled data revealed an HR of 1.50 (95% CI 1.32–1.70; p < 0.001), suggesting that patients with PD-L1 overexpression experience inferior OS. Subgroup analysis revealed that elevated PD-L1 remained a significant prognostic indicator for worse OS, irrespective of sample size, cut-off value, ethnicity, and Newcastle-Ottawa Scale score. Moreover, PD-L1 overexpression was associated with non-epithelioid histology (odds ratio 4.30 [95% CI 1.89–9.74]; p < 0.001).ConclusionsResults of this meta-analysis show that elevated expression of PD-L1 could be a factor predicting poorer survival in patients with MPM.     

Therapeutic effect of mesenchymal stem cell on Hashimoto’s thyroiditis in a rat model by modulating Th17/Treg cell balance

Abstract

The autoimmune condition Hashimoto’s thyroiditis (HT) is a disease wherein lymphocytes mediate the autoimmune damage and destruction of the thyroid gland. There are currently no effective means of treating HT, with the primary strategies of thyroid hormone therapy, surgery, or immunomodulatory therapy being associated with serious risks and side effects. There is thus a clear and urgent need to identify novel treatments for HT. In this study, we utilize female SD rats induced HT to evaluated the ability of transplanted MSCs to regulate Th17/Treg interactions in a rat Hashimoto’s thyroiditis (HT) model system. The results showed that Rats in the HT model group exhibited increased thyroid autoantibody levels consistent with successful model development, whereas these levels were lower in rats treated with MSCs. There were also fewer thyroid lesions and less lymphoid infiltration of the thyroid in MSC-treated rats relative to HT model rats, as well as fewer Th17 cells and more Treg cells – an observation consistent with the cytokine analyses. All of these showed that MSCs can regulate Th17/Treg interactions in a rat Hashimoto’s thyroiditis (HT) model system. It suggested that transplanted MSCs could be a potential immunotherapy strategy for the treatment of Hashimoto’s thyroiditis.     

Peripheral whole blood FOXP3 TSDR methylation: a potential marker in severity assessment of autoimmune diseases and chronic infections

Immune dysregulation is a cardinal feature of autoimmune diseases and chronic microbial infections. In particular, regulatory T cells are downregulated in autoimmune diseases while upregulated in chronic microbial infections. FOXP3 is the master regulator of Treg development. Treg-specific demethylated region (TSDR) is a highly conserved locus on the FOXP3 gene that is fully demethylated in natural Tregs but methylated in effector T cells. In our study, we used high resolution melt-polymerase chain reaction (HRM-PCR) to determine the FOXP3 TSDR methylation status in autoimmune diseases and chronic microbial infections. We found that FOXP3 TSDR to have the highest mean melting temperature (highly methylated) in active SLE patients compared to all the other groups (p?<?0.001). The psoriasis group also had a significantly high mean melting temperature (78.62?±?0.20) when compared with the inactive SLE group (78.49?±?0.29, p?<?0.05) and control group (78.44?±?0.25, p?<?0.01). There was no significant difference in melting temperature between inactive SLE and healthy controls. Disease activity in SLE was directly associated with methylation of the FOXP3 TSDR. On the other hand, patients with chronic microbial infections had significantly lower FOXP3 TSDR mean melting temperature (demethylated) when compared with healthy controls (78.28?±?0.21 vs 78.44?±?0.25, p?<?0.05). Our results suggest that the use of HRM-PCR to detect FOXP3 TSDR methylation status is a reliable and easy method to predict natural regulatory T cell levels in peripheral blood in different disease conditions. Determining FOXP3 TSDR methylation status can be a useful tool in diagnosis, and monitoring the severity of autoimmune diseases and chronic microbial infections.     

Sirt5 is dispensable for BrafV600E‐mediated cutaneous melanoma development and growth in vivo

Sirt5 is known to functionally regulate mitochondrial proteins by altering posttranslational modifications, including lysine desuccinylation. While roles for Sirt5 as either a tumor promoter or suppressor, or in chemoresistance, have been implicated in other cancers, the function of Sirt5 in cutaneous melanoma has not been well examined. Therefore, to determine whether Sirt5 is necessary for Braf^V600E‐mediated melanoma formation and/or disease progression, we crossed a genetically engineered murine melanoma model (Tyr^CreERT2/+; Braf^{LSL‐V600E/+}; Pten^flox/flox) to Sirt5^?/? knockout animals. In addition, we tested for synergism with a selective BRAF (V600E) inhibitor in Sirt5^?/? mouse melanoma cells. Taken together, this report demonstrates that, in these models, Sirt5 is dispensable for Braf^V600E‐mediated cutaneous melanoma formation and growth in vivo, and does not improve sensitivity to a selective BRAF inhibitor.     

Vasoactive Intestinal Peptide Immunoregulatory Role at the Periapex: Associative and Mechanistic Evidences from Human and Experimental Periapical Lesions

IntroductionThe balance between the host proinflammatory immune response and the counteracting anti-inflammatory and reparative responses supposedly determine the outcome of periapical lesions. In this scenario, the vasoactive intestinal peptide (VIP) may exert a protective role because of its prominent immunoregulatory capacity. In this study, we investigated (in a cause-and-effect manner) the potential involvement of VIP in the development of human and experimental periapical lesions.MethodsPeriapical granulomas (n = 124) and control samples (n = 48) were comparatively assessed for VIP and multiple immunologic/activity marker expression through real-time polymerase chain reaction. Experimental periapical lesions (C57Bl/6 wild-type mice) were evaluated regarding endogenous VIP expression correlation with lesion development and the effect of recombinant VIP therapy in lesion outcome. CCR4KO and IL4KO strains and anti-glucocorticoid-induced TNFR-related protein inhibition were used to test the involvement of Treg and Th2 cells in VIP-mediated effects.ResultsVIP expression was more prevalent in periapical granulomas than in controls, presenting a positive association with immunoregulatory factors and an inverse association/correlation with proinflammatory mediators and the receptor activator of nuclear factor kappa B ligand/osteoprotegerin ratio. Endogenous VIP expression up-regulation was temporally associated with lesion immunoregulation and a decline of bone loss. VIP therapy in mice prompted the arrest of lesion development, being associated with an anti-inflammatory and proreparative response that limits the proinflammatory, Th1, Th17, and osteoclastogenic response in the periapex. The VIP protective effect was dependent of Treg migration and activity and independent of interleukin 4.ConclusionsOur results show that VIP overexpression in human and experimental periapical lesions is associated with lesion inactivity and that VIP therapy results in the attenuation of experimental lesion progression associated with the immunosuppressive response involving Treg cells.     

超顺磁性氧化铁标记大鼠骨髓基质细胞经门静脉移植MRI活体示踪的研究

目的观察1．5T场强MRI联合动物专用线圈是否可以活体示踪经门静脉移植的纳米级超顺磁性氧化铁颗粒标记的骨髓基质细胞（bone marrow stromal cells BMSCs），为介人性门静脉骨髓基质细胞移植治疗终末期肝脏疾病的研究提供进一步的依据。方法供体大鼠5只，梯度密度离心分离BMSCs，纳米级超顺磁性氧化铁颗粒和脂质体转染BMSCs，体外经普鲁士蓝染色和HE染色确定细胞标记率。受体大鼠15只，分为5组，分别为对照组和纳米级超顺磁性氧化铁颗粒标记的骨髓基质细胞经门静脉移植人正常大鼠肝脏后2h、3d、7d及2周组。1．5T场强MRI联合动物专用线圈行T1W、T2W和T2＊序列扫描，观察肝脏信号改变情况，与对照组比较，并且与组织切片对照。结果纳米级超顺磁性氧化铁颗粒和脂质体转染BMSCs，细胞标记率〉95％。经门静脉移植人正常大鼠肝脏后，T2＊序列扫描显示经标记的BMSCs在肝内显示弥漫性的结节性低信号影，移植后2h到2周均可见到细胞在受体肝脏内存在，组织学切片显示信号缺失部位与铁颗粒标记细胞相一致。结论纳米级超顺磁性铁氧体颗粒标记的大鼠BMSCs经门静脉移植后可以通过1、5T场强行MRI活体示踪，为临床干细胞移植的应用提供可行的示踪方法。     

人间充质干细胞免疫原性研究

目的探讨人间充质干细胞(hMSCs)特性及免疫原性,为进一步研究hMSCs移植特性提供实验依据。方法免疫组化方法鉴定hMSCs表面HLA-ABC、HLA-DR、CD80、CD86分子;流式细胞术检测其含量;RT-PCR检测HLA-ABC、HLA-DRmRNA基因片断;外周血淋巴细胞杀伤试验及 CCK-8比色法规察淋巴细胞增殖反应;将表达绿色荧光蛋白(GFP)的DNA复合物导入hMSCs进行大鼠脑内移植,观察hMSCs在脑内的存活情况。结果 hMSCs表面少量表达HLA-ABC分子,不表达 HLA-DR、CD80、CD86分子;有少量HLA-ABC mRNA基因片断存在,未发现HLA-DR mRNA基因片断;外周血淋巴细胞杀伤试验没有发现淋巴细胞增殖反应;大鼠脑内移植hMSCs一个月后仍可见有细胞存活。结论 hMSCs具有较弱的免疫原性。     

Psoriasis confined strictly to vitiligo areas – a Koebner‐like phenomenon?

Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.     

骨形成蛋白2基因修饰的老年大鼠骨髓间充质干细胞成骨分化能力的研究

目的观察年龄因素对骨髓间充质干细胞(marrow mesenchymal stem cells, MSCs)成骨分化能力的影响;了解基因治疗对老年大鼠MSCs成骨分化能力的影响. 方法 1月龄(幼年组)、9月龄(成年组)及24月龄(老年组)雄性Wistar大鼠各6只,取MSCs经体外分离、培养及携带骨形成蛋白2(bone morphogenetic protein 2,BMP-2)基因的腺病毒载体(Ad-BMP-2)转染后,定量检测BMP-2、碱性磷酸酶(alkaline phosphate,ALP)表达,以及成骨细胞标志性蛋白:Ⅰ型胶原、骨涎蛋白(bone sialoprotein,BSP)和骨桥素(osteopontin, OPN)的表达.将转染的各组MSCs分别与磷酸三钙(tricalcium phosphate, TCP)复合后植入裸鼠体内,3周后取材,比较各组诱导异位成骨能力. 结果 ELISA检测表明BMP-2基因修饰的MSCs可以有效表达BMP-2,且表达量在各年龄组间差异无统计学意义(P>0.05);各组ALP于诱导后第9天达高峰,但组间差异均无统计学意义(P＞0.05);诱导后第7天,RT-PCR半定量检测示各组均有成骨细胞特征性蛋白,即:Ⅰ型胶原、OPN及BSP的明显表达,表达量在各组间差异无统计学意义(P>0.05);BMP-2基因转染的MSCs与TCP复合后可诱导裸鼠体内异位成骨,各组成骨量差异无统计学意义(P>0.05). 结论 BMP-2基因修饰的老年大鼠MSCs可以恢复成骨分化能力,基因治疗可能为老年性骨骼疾病提供一种新的治疗途径.