布鲁氏菌病患者中PD-1 和PD-L1 的表达

目的:研究程序性死亡受体1(PD-1) / 与配体(PD-L1) 以及相关细胞因子转化生长因子-β(Transforming growth factor-β,TGF-β)和白细胞介素-10(Interleukin-10,IL-10)在布鲁氏菌病(Brucellosis)患者中的变化。方法:选取60 例布鲁氏菌病患者与60 例健康志愿者,采用流式细胞术分别检测其外周血单个核细胞(PBMC)中CD3+ T 细胞、CD4+ T 细胞、CD8+T 细胞中PD-1 的表达,以及树突状细胞(Dendritic cell,DC)中PD-L1 的表达,同时采用流式液相多重蛋白定量技术(Cytometric bead array,CBA )检测血清中TGF-β和IL-10 的变化,采用Pearson 法分析布鲁氏菌病患者体内PD-1 与TGF-β及IL-10 的相关性,并对34 例布鲁氏菌病治愈患者进行了追踪随访。结果:与正常对照组相比,布鲁氏菌病患者组外周血中PD-1、PD-L1 的表达及血清中TGF-β和IL-10 的水平均明显升高(P<0.01),而治愈组外周血中PD-1、PD-L1 的表达及血清中TGF-β和IL-10 的水平较治疗前明显降低(P<0.01),并且布鲁氏菌病患者组PD-1 的表达与TGF-β(r =0.817,P<0.01)及IL-10 均呈正相关(r = 0.835,P<0.01)。结论:PD-1/ PD-L1 及TGF-β和IL-10 在布鲁氏菌病患者体内高表达,可能共同参与了布鲁氏菌对宿主免疫应答的负性调控作用。     

小鼠4-1BB-Fc分子的真核表达及其体外抑制T细胞增殖的效应

目的 克隆并构建含小鼠4-1BB胞外段和人IgG Fc融合基因的真核表达质粒，表达具有生物学活性的4-1BB-Fc融合蛋白，初步探讨其体外生物学效应。方法 借助RT-PCR技术，从小鼠脾脏总FLNA中扩增4-1BB全长编码基因，并导入克隆载体pGEM-T Easy。经测序证实，用PCR扩增其膜外区cDNA，酶切后与hIgG1 Fc基因一起装入真核表达载体pcDNA3．1中。应用脂质体将重组子pcDNA3．1-4-1BB-Fc转染COS-7及CHO细胞，经G418筛选，获得稳定表达4-1BB-Fc融合蛋白的CHO细胞株。双抗体夹心ELISA检测融合蛋白表达，经蛋白A亲和层析纯化，借助免疫印迹进行鉴定。应用FACS检测融合蛋白与DC细胞系DC2．4表面4-1BBL结合情况。采用MTT及CFSE（羧基荧光素乙酰乙酸）标记法检测4-1BB-Fc融合蛋白对同种异基因小鼠T细胞增殖的抑制作用。结果 经测序证实，所克隆和构建的小鼠4-1BB-Fc cDNA阅读框及连接部位序列正确；ELISA与免疫印迹证实4-1BB-Fc蛋白的表达及其对T细胞增殖具有明显抑制作用。结论 成功构建4-1BB-Fc融合基因并获稳定表达，可望用于探讨4-1BB参与移植排斥的作用及其机制。并为研究4-1BB-Fc的其他生物学作用奠定初步基础。     

树突状细胞表达的PD-L1的研究进展

树突状细胞（DC）是专职的抗原提呈细胞,通过表达多种免疫调节分子在调节T细胞免疫反应中起关键作用。其表达的PD-L1是近年来新发现的B7家族的负性共刺激分子,与其相应受体结合,能够传递负性刺激信号导致T细胞反应无力,抑制细胞因子的分泌,诱导活化T细胞凋亡,最终诱导免疫耐受,介导肿瘤免疫逃逸,并在自身免疫性疾病,病毒,细菌感染等免疫反应中起重要作用。     

人PD-L1 cDNA的克隆及其胞外区蛋白在大肠杆菌中的表达

目的：克隆人PD-L1基因的cDNA并构建PD-L1胞外区基因的原核表达载体，在大肠杆菌中进行表达。方法：以RT-PCR法从活化的人淋巴细胞总RNA中，扩增并克隆PD-L1的cDNA，构建PD-L1胞外区基因的原核表达载体，在大肠杆菌BL21(ED3)中进行表达并鉴定。结果：克隆到PD-L1 cDNA编码区的全长序列，经DNA测序证明其与已报道的序列一致。同时构建了在羧基端带有His6标签的PD-LI胞外区基因的原核表达载体，并在大肠杆菌中表达。免疫印迹分析表明，在IPTG诱导后表达的PD-L1胞外区蛋白，相对分子质量(Mr)为25000，与理论值的大小相符。该重组蛋白能与抗His6标签的单抗(mAb)特异性反应。结论：成功地克隆PD-L1基因，其胞外区蛋白在大肠杆菌中获得表达，为利用PD-L1转基因修饰移植物或以PD-L1重组蛋白抑制移植排斥反应等研究提供了条件。     

冠心病患者外周血T淋巴细胞PD-L1的表达及意义

目的研究程序性死亡配体-1（PD-L1）在冠心病患者外周血中T淋巴细胞上的表达及意义。方法按照WHO关于冠心病诊断标准,将实验分为稳定型心绞痛（SA）组（n=23）、急性冠脉综合征（ACS）组（n=21）和正常对照组（n=18）,三组均经冠状动脉造影证实。采集三组人群的外周血,用流式细胞技术及RT-PCR技术测定T淋巴细胞PD-L1蛋白及mRNA表达情况。结果与正常对照组比较,SA组和ACS组外周血T淋巴细胞PD-L1蛋白及mRNA表达水平均显著升高（P〈0.01）;但SA组与ACS组比较差异无统计学意义（P〉0.05）。结论冠心病患者外周血T淋巴细胞PD-L1表达上调,其可能在动脉粥样硬化斑块形成过程中起作用。     

PD-L1和PD-L2在树突状细胞上的表达及其生物学意义

探讨小鼠髓系DC (CD8α )中PD L1和PD L2的表达及其在T淋巴细胞活化中的作用。采用mCD4 0L CHO和TNF α分别刺激凋亡肿瘤细胞负载DC 4 8h ;免疫荧光标记检测DC表型 ;RT PCR和realtime PCR检测PD L1和PD L2mRNA转录水平 ;ELISA测定IL 2的分泌水平 ;3 H TdR掺入试验和51Cr释放试验测定DC体外激发T细胞的增殖和细胞毒杀伤率。结果显示 :PD L1和PD L2随着DC的成熟呈上调表达 ,CD4 0配基化DC的PD L1和PD L2均为中度表达 ,TNF α激发的DC为高度表达 ,二者呈现差异性表达 (P <0 0 5 ) ;CD4 0配基化髓系DC分泌IL 2的量明显高于TNF α组 (P <0 0 5 ) ,体外刺激T增殖和激活CTL能力在CD4 0配基化DC组最高 (P <0 0 5 )。提示CD4 0配基化的小鼠髓系DC呈现PD L1和PD L2的中度表达 ,IL 2大量分泌 ,这些均有助于激发有效的特异性免疫应答     

可溶性mPDL1-hIgGFc表达载体构建、表达及对诱导细胞增殖与凋亡的影响

目的 可溶性mPDL1-hIgGFc(mouse PDL1-human IgG Fc)表达载体的构建与表达,及其对诱导细胞增殖与凋亡的研究.方法 以含有mPDL1基因的载体pmPDL1为模板,采用PCR的方法获得mPDL1胞外段基因,定向连接于含有hlgGFc基因片段的载体phIgGFc,构建表达载体pmPDL1-hIgGFc;采用脂质体将重组子转染CHO细胞,转染后的CHO命名为cHOp;ELISA和Western blot法检测目的 蛋白的表达,流式细胞术检测CHOp培养上清对混合淋巴细胞培养(MLC)的影响.结果 测序结果和酶切鉴定显示构建的表达载体pmPDL1-higGFc完全正确;ELISA和Westernblot法检测CHOp培养上清中有目的 蛋白表达;流式细胞术检测表明CHOp培养上清可体外抑制小鼠MLG,并诱导活化T细胞凋亡,其效应呈剂量依赖性.结论 成功构建mPDL1-hIgGFc表达载体;mPDL1-hIgGFc在体外可抑制MLC和诱导活化T细胞凋亡,具有负性调节T细胞的功能.     

系统性红斑狼疮患者外周血B淋巴细胞PD-L1的表达

目的 探讨系统性红斑狼疮(systemic lupus erythematosus,SLE)患者外周血B淋巴细胞PD-L1的表达及其在SLE发病中的意义.方法 应用免疫荧光标记和流式细胞仪技术检测SLE患者外周血B淋巴细胞上PD-L1的表达水平.结果 活动期SLE患者外周血B淋巴细胞CD19 、CD19 /PD-L1 的表达水平明显高于SLE非活动期患者(P＜0.05)和正常对照组(P＜0.05).结论 活动期SLE患者B淋巴细胞的PD-L1表达异常增加,其可能在SLE发病机制中起重要作用.     

EGFR和PD-L1双靶向嵌合抗原受体构建及表达

目的:构建肿瘤相关抗原表皮生长因子受体特异性嵌合抗原受体(EGFR-CAR)和程序性死亡受体-配体1(PD-L1)抗体双修饰慢病毒载体表达系统。方法:人PD-L1-Fc蛋白免疫BALB/c小鼠,经细胞融合、亚克隆筛选高分泌PD-L1特异性抗体的稳定杂交瘤,酶联免疫吸附试验(ELISA)和Western blot检测抗体特异性,流式细胞术(FACS)鉴定对PD-1配受体封阻性能,Fortebio测定抗体亲和力,抗体全长测序,经保留鼠源CRD1、CRD2和CRD3人源化改造后构建单链抗体(single-chain variable fragment,scFv);人EGFR单克隆抗体杂交瘤系,经5′RACE技术扩增其轻链和重链可变区(VL和VH)基因,构建scFv,克隆至真核载体pcDNA3.1表达鉴定。基因合成EGFR-CAR(引入CD137协同信号胞内功能域)与PD-L1-scFv借助2A序列连接,克隆入慢病毒pLVX-EF1a-IRES-ZsGreen1表达载体,使用Lenti-X Packaging Single Shots (VSV-G)共同转染293T细胞,获得包装病毒,感染293V细胞,FACS测定CAR膜表达,ELISA检测CAR感染293V细胞培养上清中PD-L1-scFv表达情况,转染激活人外周血T细胞,验证CAR膜表达。结果:获得PD-L1抗体11E3,具备高度配受体封阻性能,经人源化改造后,亲和力稳定(2.67×10 -10 mol/L),EGFR-scFv获得有效表达。进一步构建了EGFR-CAR和PD-L1双修饰慢病毒分泌型CAR(CTC0537-1)及膜表达型CAR(CTC0537-2),其病毒感染293V细胞阳性率为10%。CTZ0431-1感染293V细胞后,细胞膜表面表达EGFR-scFv,检测培养上清存在PD-L1-ScFv;CTZ0431-2感染293V细胞后,细胞膜表面EGFR-scFv和PD-L1-scFv有效表达,双表达病毒感染活化T细胞的CAR表达率为39.3%。 结论:成功构建了EGFR-CAR和PD-L1-scFv双表达慢病毒载体,EGFR-CAR中度结合亲和力,此为EGFR靶向和PD-L1抗体双修饰CAR-T细胞的实体瘤治疗研究提供了关键工具。     

晚期胃癌中PD-1/PD-L1的表达及其单抗治疗的临床现状

随着对肿瘤免疫逃逸机制研究的不断深入,PD-1及其配体PD-L1构成的PD-1/PD-L1通路被证实与晚期胃癌患者生存期相关,且PD-L1作为疗效预测标志物具有一定临床价值。在晚期胃癌的局部维持治疗、二线治疗及部分一线治疗的临床试验中,PD-1/PD-L1抑制剂均获得了较好的治疗效果。PD-1/PD-L1抑制剂联合放化疗、细胞因子与其他免疫抑制剂及JAK2/STAT1/IRF-1信号通路靶向治疗也有一定成效。文章就PD-1/PD-L1免疫检查点抑制剂用于晚期胃癌治疗的现状进行回顾,并对其假定的生物标志物,正在进行的试验以及今后的发展进行讨论。     

耐受性树突状细胞过继转移建立1型糖尿病小鼠感染性免疫耐受

目的探讨耐受性树突状细胞(DC)过继转移,在T1DM模型小鼠体内建立感染性免疫耐受的方法和机制。方法在链脲佐菌素(STZ)所致1型糖尿病模型(type 1 diabetes mellitus,T1DM)内采用胰岛素与IFA混合乳剂皮下注射的方式诱导免疫耐受。体外分离和纯化耐受性树突状细胞。另取BALB/c小鼠,通过体内腹腔注射STZ,尾静脉注射T1DM发病小鼠脾脏T淋巴细胞(DTL),诱导T1DM。同时将不同来源DC经腹腔注射入模型小鼠体内。每周测定血糖,第4周时处死动物,取胰腺进行病理组织学检查。MTF法测定小鼠脾淋巴细胞增殖反应,采用流式细胞术检测CIM~ CD25~ 调节性T细胞。结果采用2次小剂量STZ加DTL联合注射的方式可在小鼠体内建立以胰腺β细胞炎性破坏为主要病理特征的T1DM。通过过继转移免疫耐受性DC,可明显降低糖尿病高血糖以及小鼠脾淋巴细胞增殖能力,与模型对照组差异有统计学意义(P<0.01);组织病理检查发现胰岛内炎症细胞浸润减少,组织结构完整;FACS显示CD4~ CD25~ T细胞亚群比例显著升高。结论过继转移耐受性DC可以在次一级T1DM模型内诱导感染性免疫耐受并防止T1DM的发生,其机制与促进体内CD4~ CD25~ T细胞亚群产生相关。     

PD-L1信号对T细胞体外激发的调节作用

目的　探讨PD L1信号在PHA体外激发体系中对人外周血T细胞的协同调节作用。方法　采用 10 μg/mlPHA刺激人外周血T细胞体外培养体系 ,加入转基因细胞PD L1/L92 9混合培养 ;免疫荧光标记和流式细胞仪分析T细胞表型及细胞周期 ;3 H TdR掺入法观察T细胞的增殖 ;ELISA法检测T细胞对IL 2和IFN γ的产生。结果　PD L1转基因细胞在PHA激发T细胞增殖的培养体系中 ,具有显著下调T细胞活化表型 ,抑制T细胞对PHA促增殖的反应性 ,这种抑制效应与其阻断T细胞于G0 /G1细胞周期及使活化T细胞分泌IL 2和IFN γ的水平下降有关。同时还发现PD L1信号能抑制PHA介导的T细胞活化诱导凋亡。结论　PD L1信号在体外PHA激发T细胞培养体系中 ,具有显著的负性调节其活化增殖和相应功能的作用     

Clinicopathological significance of PD-L1 expression in colorectal cancer: Impact of PD-L1 expression on pFOXO1 expression

ObjectiveThis study aimed to evaluate the clinicopathological significance of PD-L1 expression and its impact on phospho-Forkhead box O 1 (pFOXO1) expression in colorectal cancer (CRC).MethodsImmunohistochemical analysis for PD-L1 and pFOXO1 was performed on 265 human CRC tissues. PD-L1 expression was evaluated in the tumor and immune cells. The impact of PD-L1 expression on survival was investigated in relation to the pattern of pFOXO1 expression.ResultsPD-L1 was expressed in 25 (9.4%) and 41 (17.7%) patients in the tumor and immune cells of the 265 CRC tissues, respectively. PD-L1 expression in immune cells (I-PD-L1) was significantly correlated with less lymphatic invasion, lymph node metastasis, and distant metastasis and lower pT and pTNM stages. Additionally, there was a significant correlation between PD-L1 expression in tumor cells (T-PD-L1) and tumor location (right colon), but not the other clinicopathological characteristics. pFOXO1 expression was significantly lower in CRC with high I-PD-L1 expression than in CRC with low or negative I-PD-L1 expression. However, there was no significant correlation between pFOXO1 and T-PD-L1 expression in CRC. Patients with positive pFOXO1 and low or negative I-PD-L1 expression exhibited the worst survival among patients with CRC.ConclusionCollectively, our results indicate that I-PD-L1 expression was significantly correlated with favorable tumor behaviors and better survival. In addition, patients with high I-PD-L1 and low pFOXO1 expressions had a favorable prognosis than those with other I-PD-L1 and pFOXO1 expression patterns.     

Analysis of children with type 1 diabetes in Korea: high prevalence of specific anti-islet autoantibodies, immunogenetic similarities to Western populations with "unique" haplotypes, and lack of discrimination by aspartic acid at position 57 of DQB

This study analyzed the expression of anti-islet autoantibodies and HLA-DR and -DQ genotypes in Korean children with type 1 diabetes mellitus (T1DM). The positivity of the anti-ICA512, anti-GAD65, and anti-insulin autoantibodies in the newly onset T1DM patients (n = 15) was 66.7%, 86.7%, and 46.7%, respectively, and all of them had one or more of the autoantibodies. HLA analysis showed higher frequencies of HLA-DRB1*0301, *0405, *09012 and -DQB1*0201, *0401, *03032 alleles in T1DM patients compared to controls (P(c) < 0.05). Because HLA-DQB1*0401, *03032 alleles carry aspartic acid at position 57 of DQB, susceptibility to T1DM in Korean children was not related to the presence of aspartic acid at position 57 of DQB1 locus. We suggest this unique HLA-DR, -DQ allele distribution might be an important factor for the low incidence of T1DM in Korea, and the combined anti-islet autoantibody assays could be valuable screening markers for the early detection of T1DM in Korea.     

PD-L1阻断改善酵母多糖致伤小鼠脾脏耐受性 DC对T淋巴细胞活性的影响

目的：探讨酵母多糖致伤小鼠脓毒症病程发展过程中脾脏耐受性树突状细胞( dendritic cell, DC)的形成对脾脏T淋巴细胞免疫活性的影响,并通过程序性死亡受体-1(programmed death-1,PD-L1)抗体阻断PD-L1/PD-1途径改善耐受性DC对T淋巴细胞活性的抑制作用。方法采用酵母多糖腹腔注射的方法复制小鼠脓毒症模型。用磁珠法分离致伤小鼠脾脏DC和T淋巴细胞,测定脾脏组织中DC上PD-1、PD-L1、PIR-B的表达水平和分泌IL-12、IL-10的能力;检测脾脏T淋巴细胞增殖活性和IL-2的分泌水平。进一步将致伤组小鼠脾脏DC与正常小鼠脾脏T淋巴细胞混合培养,并加入PD-L1抗体,检测T淋巴细胞增殖活性及混合培养上清中IL-2、IL-12和IL-10含量。结果酵母多糖致伤后5天和12天组小鼠脾脏DC上PD-1、PD-L1及PIR-B的表达大幅上调,IL-12p70分泌减少,IL-12p40和IL-10分泌增加;脾脏T淋巴细胞增殖活性降低、IL-2分泌减少。在致伤组DC与正常T淋巴细胞混合培养体系中加入PD-L1抗体可减轻致伤组DC对T淋巴细胞增殖活性和分泌IL-2的抑制作用,并改善DC上IL-12p70、IL-12p40和IL-10的分泌能力。结论酵母多糖诱导小鼠脓毒症的病程晚期,脾脏耐受性DC的形成导致T淋巴细胞活性降低;PD-L1抗体通过干预PD-1/PD-L1途径改善T淋巴细胞和DC的免疫活性。     

Lactate up-regulates the expression of PD-L1 in kidney and causes immunosuppression in septic Acute Renal Injury

BackgroundThis study aims to explore the mechanism of immunosuppression in septic Acute Renal Injury (AKI) and the role of programmed death-1 (PD-1/PD-L1) pathway in septic AKI.MethodsThis study established a septic AKI model by Cecal ligation and puncture (CLP) in C57/B6 mice, ELISA was used to test the level of lactate and creatinine in serum, blood was collected for flow cytometry and kidney samples for Western blot analyses. This study further analyzed the expression of PD-L1 in kidney and the expression of PD-1 in CD4+, CD8+ T cell, and the number of CD3+ T cells to identify apoptosis in T cells in the blood.ResultsThe CLP sepsis model induced AKI in C57/B6 mice; The expression of PD-1 and PD-L1 were increased in septic AKI mice; PD-1/PD-L1 induced apoptosis in T cells: the number of lymphocytes decreased by 64%, while the number of CD3+ T cells decreased by 27% compared with the sham group; Results also indicated that lactate up-regulates expression of PD-L1 in the kidney.ConclusionsLactate activated PD-1/PD-L1 pathway can induce immunosuppression by inducing apoptosis in lymphocytes in septic AKI. Moreover, blocking the receptor of lactate or PD-1/PD-L1 might be a new therapy for septic AKI.     

L-Methionine prevents β-cell damage by modulating the expression of Arx,MafA and regulation of FOXO1 in type 1 diabetic rats

L-Methionine (L-Met) is an essential sulphur-containing amino acid having a vital role in various key cellular processes. Here we investigated the effect of L-Met on streptozotocin-induced β-cell damage model of diabetes mellitus in Sprague Dawley rats. At the end of study biochemical parameters, immunoblotting, qRT-PCR and ChIP-qPCR are performed. L-Met was administered orally (250 and 500 mg/kg/day) to diabetic animals for 8 weeks improved plasma glucose and insulin levels. Pancreas immunohistochemistry showed significant increase in insulin expression, decrease in glucagon and Bax expression. Interestingly, L-Met inhibited the expression of Arx; upregulated MafA and FOXO1 which play a critical role in the maintenance of β-cell identity. Our data also showed a decrease in H3K27me3 and an increase in H3K4me3 ("bivalent domain" alteration) in diabetic rats and these recovered by L-Met. Furthermore, the chromatin-immunoprecipitation assay showed a decreased enrichment of H3K27me3 on the promoter of the FOXO1 gene in diabetic rats and L-Met prevents this decrease. Our results showed the first evidence of the involvement of H3K27me3 in regulating the expression of the FOXO1 gene and the prevention of β-cell injury by L-Met treatment. In conclusion, we report the involvement of L-Met in the modulation of α-cell identity marker (Arx), β-cell identity marker (MafA) and regulation of FOXO1 by histone methylation marks for the first time. We are of the opinion that this employed as a novel therapeutic approach for mitigating diabetes-induced β-cell death.