Herpesvirus entry mediator (HVEM) attenuates signals mediated by the lymphotoxin β receptor (LTβR) in human cells stimulated by the shared ligand LIGHT

Signals mediated by members of the tumor necrosis factor receptor superfamily modulate a network of diverse processes including initiation of inflammatory responses and altering cell fate between pathways favoring survival and death. Although such pathways have been well-described for the TNF-α receptor, less is known about signaling induced by the TNF superfamily member LIGHT and how it is differentially altered by expression of its two receptors LTβR and HVEM in the same cell. We used cell lines with different relative expression of HVEM and LTβR to show that LIGHT-induced signals mediated by these receptors were associated with altered TRAF2 stability and RelA nuclear translocation. Production of the inflammatory chemokine CXCL10 was primarily mediated by LTβR. Higher expression of HVEM was associated with cell survival, while unopposed LTβR signaling favored pathways leading to apoptosis. Importantly, restoring HVEM expression in cells with low endogenous expression recapitulated the phenotype of cells with higher endogenous expression. Together, our data provide evidence that relative expression of HVEM and LTβR modulates canonical NF-κB and pro-apoptotic signals stimulated by LIGHT.     

BTLA:一个新发现的CD28超家族共刺激分子

BTLA是新近发现的一个CD8超家族共刺激分子,它与CTLA-4、PD-1有相似的结构和功能,对T细胞活化起负性调控作用,同时还可作为胸腺细胞阳性选择的早期标志。研究发现BTLA可与HVEM直接结合,目前多认为HVEM是BTLA的配体。BTLA—HVEM相互作用沟通了CD28及TNFR两个共刺激分子超家族,是一个比较特别的．CD28超家族分子。     

人BTLA-Fc融合蛋白的制备及其生物学活性的研究

为建立CHO/BTLA-Fc基因转染细胞株,使之能稳定分泌BTLA-Fc融合蛋白,采用PCR法从本单位构建的pEGZ-Term/B7-H1-Fc重组质粒中扩增人IgG1(Fc)恒定区,Xho I、BamH I双酶切后与真核表达载体pIRES2-EGFP连接为重组质粒pIRES2-EGFP-Fc,同时PCR法从pEGZ-Term/BTLA重组质粒中获得人BTLA胞外段基因片段,用Nhe I、Xho I双酶切插入上述pIRES2-EGFP-Fc构建重组载体pIRES2-EGFP/BTLA-Fc。脂质体法以该重组载体转染鼠CHO细胞,G418筛选并亚克隆化。Protein G亲和层析柱对上清中的融合蛋白进行纯化,Western blot作定性分析。CCK-8检测BTLA-Fc融合蛋白对抗人CD3单抗激发的T淋巴细胞增殖的影响。结果表明,基因转染CHO细胞培养上清中表达的BTLA-Fc融合蛋白能与L929/HVEM细胞有效结合,纯化的融合蛋白经Western blot鉴定有清晰的目的条带,而且BTLA-Fc融合蛋白对T细胞的体外增殖具有抑制作用。     

shRNA介导BTLA基因沉默对小鼠脾淋巴细胞增殖的影响

目的 探讨RNA干扰负性共刺激分子B和T淋巴细胞衰减因子(BTLA)表达后小鼠淋巴细胞增殖的变化.方法 构建小鼠BTLA基因小发夹RNA(shRNA)质粒载体pSiencer 3.1-BTLA/shRNA,与H1启动子共同亚克隆至慢病毒载体pLB,包装病毒后转导小鼠脾淋巴细胞,流式细胞术(FCM)检测感染效率及BTLA分子表达水平.以刀豆蛋白A(ConA)及抗CD3单抗刺激BTLA shRNA干扰组为实验组,以未行基因沉默组为对照组,CCK-8法测定各组淋巴细胞增殖水平.结果 成功构建3个pLB-BTLA shRNA慢病毒干扰载体和一个非特异性shRNA载体,并制备高滴度病毒.特异性shRNA干扰组BTLA表达水平较对照组明显降低(约40%).抗CD3单抗刺激BTLA shRNA转染的淋巴细胞后增殖水平(A450值)显著增高(3.80±0.58),与未转染shRNA对照组(2.42±0.72)相比差异有统计学意义(P＜0.05),而ConA刺激后细胞增殖水平shRNA转染组与未转染组相比差异无统计学意义(P＞0.05);组间相比,BTLA基因沉默的小鼠脾淋巴细胞经抗CD3单抗处理后细胞增殖水平较ConA处理组明显增高(P＜0.05).结论 慢病毒载体携带的特异性shRNA可有效干扰小鼠脾淋巴细胞BTLA基因的表达,BTLA基因沉默对淋巴细胞增殖具有促进作用.     

BTLA expression declines on B cells of the aged and is associated with low responsiveness to the trivalent influenza vaccine

Virus-neutralizing antibody and B cell responses to influenza A viruses were measured in 35 aged and 28 middle-aged individuals following vaccination with the 2012 and 2013 trivalent inactivated influenza vaccines. Antibody responses to the vaccine strains were lower in the aged. An analysis of B cell subsets by flow cytometry with stains for immunoregulators showed that B cells of multiple subsets from the aged as compared to younger human subjects showed differences in the expression of the co-inhibitor B and T lymphocyte attenuator (BTLA). Expression of BTLA inversely correlated with age and appears to be linked to shifting the nature of the response from IgM to IgG. High BTLA expression on mature B cells was linked to higher IgG responses to the H1N1 virus. Finally, high BTLA expression on isotype switched memory B cells was linked to better preservation of virus neutralizing antibody titers and improved recall responses to vaccination given the following year.     

HIV早期和慢性感染者不同亚群T细胞BTLA的表达

目的:对中国HIV早期和慢性感染者不同亚群T细胞BTLA表达水平及与疾病进展相关性进行研究,探讨BTLA表达在HIV感染中的作用。方法:选取21例HIV早期感染者、29例HIV慢性感染者及23例正常对照,应用流式细胞仪检测CD4+CD45RA+、CD4+CD45RA-、CD8+CD45RA+、CD8+CD45RA-及总CD4+、CD8+T细胞BTLA表达水平,同时分析CD4+HLA-DR+、CD4+CD38+、CD8+HLA-DR+、CD8+CD38+T细胞表达水平,分析不同亚群T细胞BTLA表达水平与疾病进展及免疫活化的相关性。结果:HIV早期感染组各亚群T细胞BTLA表达水平高于正常对照,其中CD4+CD45RA-、CD8+CD45RA-、总CD4+T细胞BTLA表达水平在两组之间差异具有统计学意义(P<0.01);HIV早期感染组各亚群T细胞BTLA表达水平高于慢性感染者,除CD8+CD45RA-T细胞外,其它亚群T细胞BTLA表达水平在两组之间差异具有统计学意义(P<0.01);慢性HIV感染者CD8+CD45RA+T细胞BTLA表达水平低于正常对照,差异显著(P<0.01),其余T细胞亚群BTLA表达水平在两组之间无明显差异。HIV感染者T细胞亚群BTLA表达水平与T细胞活化水平负相关:除CD8+CD45RA-T细胞外,各亚群T细胞BTLA表达百分率与T细胞活化(CD4+HLA-DR+T细胞表达)水平明显负相关(P<0.01);各亚群T细胞BTLA表达水平与CD4+CD38+、CD8+CD38+T细胞表达水平无明显相关性。HIV感染者总CD8+T细胞BTLA表达水平与CD4+T细胞数量明显正相关(P<0.01)。结论:中国HIV感染者T细胞BTLA表达与疾病进展及免疫活化状况显著相关,早期感染阶段BTLA表达升高,慢性感染期表达下降,为明确HIV的致病机制及免疫治疗提供线索。     

LIGHT-HVEM—BTLA共信号分子的研究进展

BTLA是新近发现的一个CD28超家族共抑制分子,它的配体不是B7家族成员而是TNF受体超家族成员HVEM。HVEM同时还存在一个TNF超家族的配体,即T细胞上可诱导表达的与HSV的糖蛋白D竞争结合HVEM的淋巴毒素类似物（LIGHT）。HVEM可以作为一个分子开关,通过结合LIGHT或BTLA7E免疫调节中发挥不同的作用。     

子宫内膜癌组织中LAG - 3、TIM - 3、BTLA 的表达情况及意义

目的 研究子宫内膜癌组织中LAG - 3、TIM - 3、BTLA 的表达及其临床意义。方法 选取2012年1月 - 2016年12月于徐州医科大学附属医院行全子宫切除术患者120例,其中术后病理证实为子宫内膜癌组织60例、子宫内膜不典型增生组织30例、正常子宫内膜组织30例。采用免疫组化染色方法,检测LAG - 3、TIM - 3、BTLA 在不同内膜组织中的表达情况,并分析三者的表达与子宫内膜癌患者临床病理特征的相关性。采用 Kaplan - Meier生存分析,COX回归模型分析方法,探索子宫内膜癌患者预后的影响因素。结果 子宫内膜癌组织中,LAG - 3、TIM - 3、BTLA的表达率较子宫内膜不典型增生组、正常子宫内膜组均增高（P均＜0.05）。患者的年龄、分化程度、病理类型均不影响LAG - 3、TIM - 3、BTLA的阳性表达（P均＞0.05）,而肿瘤临床分期、淋巴结转移可以影响LAG - 3、TIM - 3、BTLA的表达（P均＜0.05）;肿瘤肌层浸润程度会影响TIM - 3、BTLA的阳性表达,但对LAG - 3的表达无显著影响。Cox回归分析结果显示:FIGO分期、淋巴结转移、LAG - 3、TIM - 3、BTLA蛋白的阳性表达与患者预后相关（P均＜0.05）,LAG3、TIM3、BTLA是患者生存的独立危险因素。结论 LAG - 3、TIM - 3、BTLA在子宫内膜癌组织中均有较高表达,且均为患者预后的负性影响因子。     

Immunoregulation of Dendritic Cell Subsets by Inhibitory Receptors in Urothelial Cancer

Blockade of inhibitory receptors (IRs) overexpressed by T cells can activate antitumor immune responses, resulting in the most promising therapeutic approaches, particularly in bladder cancer, currently able to extend patient survival. Thanks to their ability to cross-present antigens to T cells, dendritic cells (DCs) are an immune cell population that plays a central role in the generation of effective antitumor T-cell responses. While IR function and expression have been investigated in T cells, very few data are available for DCs. Therefore, we analyzed whether DCs express IRs that can decrease their functions. To this end, we investigated several IRs (PD-1, CTLA-4, BTLA, TIM-3, and CD160) in circulating CD1c⁺ DCs, CD141⁺ DCs, and plasmacytoid DCs from healthy donors and patients with urothelial cancer (UCa). Different DC subsets expressed BTLA and TIM-3 but not other IRs. More importantly, BTLA and TIM-3 were significantly upregulated in DCs from blood of UCa patients. Locally, bladder tumor–infiltrating DCs also overexpressed BTLA and TIM-3 compared to DCs from paired nontumoral tissue. Finally, in vitro functional experiments showed that ligand-mediated engagement of BTLA and TIM-3 receptors significantly reduced the secretion of effector cytokines by DC subpopulations. Our findings demonstrate that UCa induces local and systemic overexpression of BTLA and TIM-3 by DCs that may result in their functional inhibition, highlighting these receptors as potential targets for UCa treatment.