PD-L1 与TIL 在免疫治疗中的预测作用及临床意义

随着程序性死亡因子-1(PD-1)/程序性死亡因子配体-1(PD-L1)单抗陆续在中国获批,PD-1/PD-L1抑制剂是目前肿瘤免疫治疗领域的研究热点之一。研究显示PD-1/PD-L1单抗免疫治疗效果与肿瘤细胞中PD-L1的表达水平有关,然而仅仅依靠肿瘤细胞中PD-L1的表达并不能完全预测PD-1/PD-L1单抗治疗效果。PD-1/PD-L1单抗免疫治疗效果也与肿瘤微环境中肿瘤浸润的淋巴细胞(TIL)有关。根据瘤细胞PD-L1的表达以及TIL将肿瘤分为四种免疫类型,不同类型应用PD-1/PD-L1单抗治疗疗效不同。因此,本文对肿瘤细胞PD-L1表达联合TIL预测PD-1/PD-L1单抗免疫治疗疗效进行综述。     

PD-1/PD-L1免疫抑制剂在肺癌临床治疗和病理检测中的研究进展

以程序性细胞死亡蛋白-1(programmed death-1, PD-1)及其配体(programmed death-ligand 1, PD-L1)抑制剂为代表的免疫治疗,在多种肿瘤(包括肺癌)的治疗上有出色的表现。对于非小细胞肺癌(non-small cell lung cancer, NSCLC)的治疗,除了基于驱动基因突变的靶向治疗,其耐药后及驱动基因野生型患者的下一步治疗可以根据检测相关标志物进行PD-1/PD-L1免疫治疗;对于小细胞肺癌(small cell lung cancer, SCLC),除了化疗方案,近些年陆续有多种PD-1/PD-L1免疫抑制剂获批用于SCLC的适应症。对可能预测PD-1/PD-L1抑制剂疗效的相关病理检测指标,目前并未达成一致的结论。该文就近年来对PD-1/PD-L1相关的免疫治疗在NSCLC和SCLC治疗和病理检测中的研究进展作一综述。     

PD-1及PD-L1与肿瘤适应性免疫抵抗的研究进展

程序性死亡蛋白-1(programmed death protein 1,PD-1)与其配体程序性死亡配体1(programmed cell death-ligand 1,PD-L1)属于CD28/B7家族,是近年研究比较透彻的免疫检查点分子。PD-1/PD-L1通过调节外周组织中免疫反应的持续性和效价避免组织损伤并维持对于自身抗原的耐受。肿瘤细胞主动性抑制T细胞的机制称为适应性免疫抵抗(adaptive immune resistance),即肿瘤抗原特异性T细胞企图攻击肿瘤,但肿瘤细胞发生反应性改变(诱导表达PD-L1)从而避免免疫攻击。适应性免疫抵抗过程中的关键分子即为PD-1/PD-L1。PD-1/PD-L1抗体治疗已在临床试验中显示出良好的疗效,使阻断适应性免疫抵抗有望成为重要的肿瘤免疫治疗手段。分析肿瘤活检样本的基线免疫信息能指导制定个体化的免疫治疗方案。本文就PD-1/PD-L1的生物学结构、适应性免疫抵抗机制及相关临床决策等进行综述。     

PD-1/PD-L1在非小细胞肺癌中的研究进展及展望

PD-1(programmed cell death-1,程序性死亡受体1)与其配体PD-L1(programmed cell death-ligand 1,程序性死亡配体1)属于CD28/B7家族,是一对共刺激分子,具有负性调控作用。PD-1通过与其配体PD-L1结合调节肿瘤的微环境,使肿瘤细胞免于机体免疫系统的监视和清除。目前已有较多研究显示PD-1/PD-L1在非小细胞肺癌组织中的表达水平与患者的临床病理因素及预后存在显著的相关性。在非小细胞肺癌的治疗领域,以PD-1/PD-L1为代表的免疫治疗成为继手术治疗、化疗、放疗、分子靶向治疗之后的新焦点。PD-1/PD-L1抑制剂在一系列非小细胞肺癌临床试验中也显示出了巨大的临床潜力。本文就PD-1/PD-L1的生物学结构及其在非小细胞肺癌中的作用机制、研究进展及展望作一综述。     

PD-1/PD-L1抗体治疗非小细胞肺癌的临床研究进展

近年来,肺癌以其高发病率、高病死率以及低5年生存率而受到广泛重视。除传统的手术、放疗、化疗及靶向治疗外,针对肺癌的免疫治疗也已逐步开展。抗PD-1/PD-L1疗法的研究进展迅速,本文综述目前以抗PD-1/PD-L1治疗性抗体作为药物治疗非小细胞肺癌的研究进展。     

阻断PD-1/PD-L1通路的免疫疗法在恶性肿瘤治疗中的研究进展

近年来,程序性死亡受体1(programmed death receptor 1, PD-1)/程序性死亡配体1(programmed death ligand 1,PD-L1)信号通路作为介导肿瘤免疫逃逸的重要途径而备受关注,抑制甚至阻断PD-1/PD-L1通路以增强T细胞毒性作用、提高机体免疫应答成为当下研究热点并取得了一系列突破性成果。目前,以PD-1/PD-L1抑制剂和CRISPR-Cas9技术靶向敲除PD-1/PD-L1基因为代表的免疫治疗策略已开始从实验室走向临床。与此同时,新的免疫治疗靶点的发现和治疗策略的组合将有助于更好地实现对PD-1/PD-L1信号通路的抑制作用,从而更有效地发挥此种免疫疗法在肿瘤治疗中的辅助作用。但目前阻断PD-1/PD-L1通路的免疫疗法仍存在适用人群有限、治疗效果相对欠佳等缺陷。此外,传统的肿瘤治疗评价标准对免疫疗法并不完全适用,新的标准亟待完善并规范化以用于临床疗效评价。本文将从PD-1/PD-L1信号通路出发,简明阐述其机制,并对当前研究成果进行全面介绍,同时聚焦国内外最新研究进展并对这一领域的发展趋势作出展望。     

RNAscope原位杂交技术在胃癌PD-1、PD-L1表达分析中的应用

目的 探讨RNAscope原位杂交技术在检测胃癌程序性死亡受体-1(programmed death 1, PD-1)及程序性死亡配体-1(programmed death-ligand 1, PD-L1)表达中的应用价值。方法 利用RNAscope原位杂交技术检测255例胃癌中PD-1、PD-L1 mRNA表达水平;应用免疫组化EnVision法检测255例胃癌中PD-1、PD-L1蛋白表达水平。结果 RNAscope检测结果显示：PD-1、PD-L1 mRNA阳性为细胞质或细胞核中有棕黄色颗粒状物。PD-1 mRNA阳性定位于肿瘤间质免疫细胞,PD-L1 mRNA阳性定位于肿瘤细胞或肿瘤间质免疫细胞。PD-1 mRNA阳性率为20.39%(52/255),PD-L1 mRNA阳性率为14.12%(36/255)。免疫组化检测显示：PD-1阳性定位于细胞质,PD-1主要表达于肿瘤间质免疫细胞;PD-L1可表达于肿瘤细胞或肿瘤间质免疫细胞,肿瘤细胞PD-L1阳性定位于细胞膜(部分或完全膜染色),免疫细胞PD-L1阳性定位于细胞质或细胞膜。PD-1蛋白阳性率为14.12%(36/255)...     

阻断CLTA-4/PD-1联合化疗药物在肿瘤治疗中的应用

化学药物治疗（化疗）是目前治疗肿瘤最有效的手段之一，但单独应用化学药物存在肿瘤靶向能力差、副作用严重、容易导致肿瘤耐药等弊端。免疫治疗是通过重新启动并维持肿瘤-免疫循环，恢复机体正常抗肿瘤免疫反应，从而控制与清除肿瘤的治疗方法。免疫检查点抑制剂（ICIs）是免疫治疗中的一类常规药物，以抗程序性死亡蛋白1(PD-1)抗体和细胞毒性T淋巴细胞抗原4(CTLA-4)抑制剂为代表。研究者发现通过阻断CLTA-4或PD-1与化疗药物联用，不仅能发挥化疗药物对肿瘤的细胞毒作用，还可通过促进淋巴细胞的增殖与活化、弥补化学治疗抑制机体免疫的弊端、促进并维持记忆T细胞增殖等一系列促进免疫系统发挥作用的方式提高抗肿瘤效果。本文对联合治疗的实验室和临床研究模式，及其作用机制进行综述。     

肝癌靶向载体药物的靶向作用与应用分析

背景：肝癌是常见的恶性肿瘤之一,选择有效的治疗药物及治疗方法具有重要的意义。 目的：评价载体缓释化疗药物对肝癌的靶向治疗作用及效果。 方法：分析临床常用的肝癌化疗药物5-氟尿嘧啶、丝裂霉素以及表阿霉素载体缓释系统对肝脏肿瘤的靶向性特征以及对肿瘤的抑制和杀伤作用。并观察总结海南省农垦总医院肿瘤内科163例中晚期肝癌患者应用化疗药物5-氟尿嘧啶、丝裂霉素、表阿霉素,同时采用导管动脉化疗栓塞辅助治疗的临床效果。 结果与结论：5-氟尿嘧啶、丝裂霉素以及表阿霉素载体缓释系统通过不同的作用机制显示出对肝脏肿瘤的靶向性特征,并且对肝脏肿瘤具有较高的抑制和杀伤作用,减少药物用量,降低毒副作用,提高治疗效果。此外,治疗时辅助应用导管动脉化疗栓塞可以延长患者的生存期,提高肝癌的治疗效果。     

PD-1及其配体在实体肿瘤中的应用

程序性死亡生长因子-1( PD-1/CD279)是新近研究的热门分子,PD-1与其配体PD-L1/2(B7-H1/CD274)最终导致淋巴细胞“耗尽”以及诱导免疫耐受。 PD-L1在肿瘤细胞中可呈高表达,其异常表达与患者预后密切相关。最近越来越多的研究关注于PD-1、PD-L1/2在各类实体肿瘤中的表达,日前美国食品及药物管理局 FDA 批准 Keytruda ( pembroli-zumab)用于治疗对其它药物治疗无效的晚期或无法切除的黑色素瘤患者,其机制是Keytruda能阻断PD-1细胞通路,这些均提示针对PD-1、PD-L1/2分子治疗可能成为肿瘤治疗的突破点,且PD-1、PD-L1/2在实体肿瘤的表达可能成为预后评估新生物学的标志物。该文现就PD-1、PD-L1/2在肿瘤中的研究新进展作一综述。     

Blockage of immune checkpoint molecules increases T-cell priming potential of dendritic cell vaccine

Dendritic cell (DC) -based cancer immunotherapy is one of the most important anti-cancer immunotherapies, and has been associated with variable efficiencies in different cancer types. It is well-known that tumor microenvironment plays a key role in the efficacy of various immunotherapies such as DC vaccine. Accordingly, the expression of programmed death ligand 1 (PD-L1) on DCs, which interacts with PD-1 on T cells, leads to inhibition of anti-tumor responses following presentation of tumor antigens by DCs to T cells. Therefore, we hypothesized that down-regulation of PD-L1 in DCs in association with silencing of PD-1 on T cells may lead to the enhancement of T-cell priming by DCs to have efficient anti-tumor T-cell responses. In this study, we silenced the expression of PD-L1 in DCs and programmed cell death protein 1 (PD-1) in T cells by small interfering RNA (siRNA) -loaded chitosan–dextran sulfate nanoparticles (NPs) and evaluated the DC phenotypic and functional characteristics and T-cell functions following tumor antigen recognition on DCs, ex vivo. Our results showed that synthesized NPs had good physicochemical characteristics (size 77·5 nm and zeta potential of 14·3) that were associated with efficient cellular uptake and target gene silencing. Moreover, PD-L1 silencing was associated with stimulatory characteristics of DCs. On the other hand, presentation of tumor antigens by PD-L1-negative DCs to PD-1-silenced T cells led to induction of potent T-cell responses. Our findings imply that PD-L1-silenced DCs can be considered as a potent immunotherapeutic approach in combination with PD-1-siRNA loaded NPs, however; further in vivo investigation is required in animal models.     

Immune checkpoint blockade and biomarkers of clinical response in non–small cell lung cancer

Immunotherapy with PD-1 and PD-L1 inhibitors has revolutionized the treatment for patients with NSCLC the last years with increased overall survival and in particular increased number of long-time survivors in patients with metastatic disease. It is now a treatment of choice for patients with distant metastases (stage IV) and in conjunction with chemoradiotherapy for patients with limited spread confined to the chest (stage III). PD-1 inhibition has been proven to be superior to standard chemotherapy, both as a single treatment and when combined with either chemotherapy or CTLA-4 inhibition. Despite the success of immunotherapy, the majority of patients do not respond or relapse within a short time frame. Biomarkers that would help to properly select patients with a high likelihood of clinical response to PD-1 and PD-L1 inhibitors are scarce and far from optimal, and only one (PD-L1 expression) has reached clinical practice. Thus for immunotherapy to be effective, the discovery and validation of additional biomarkers is critical for patient selection and prediction of clinical response. In this mini-review, we give an overview of current clinical management of NSCLC including treatment landscape with regard to immunotherapy, as well as discuss the current genetic and immune cell biomarker studies and their potential for introduction into clinical practice.     

Targeting the PD-1/B7-H1(PD-L1) pathway to activate anti-tumor immunity

Genetic alterations and epigenetic dysregulation in cancer cells create a vast array of neoepitopes potentially recognizable by the immune system. Immune checkpoint blockade has the capacity to enhance and sustain endogenous immunity against non-mutated tumor-associated antigens as well as uniquely mutant antigens, establishing durable tumor control. Recent evidence from preclinical models highlights the pivotal role of the Programmed Death-1 (PD-1) T cell co-receptor and its ligands, B7-H1/PD-L1 and B7-DC/PD-L2, in maintaining an immunosuppressive tumor microenvironment. Encouraging early clinical results using blocking agents against components of the PD-1 pathway have validated its importance as a target for cancer immunotherapy.     

Chemopreventive agents induce programmed death-1-ligand 1 (PD-L1) surface expression in breast cancer cells and promote PD-L1-mediated T cell apoptosis

Chemotherapy has been widely used in cancer treatment. However, the prognosis of the cancer patients following chemotherapy has not been substantially improved. Alternative strategies such as immunotherapy and their combinations with chemotherapy are now being considered. Yet, the effects of chemotherapy on the immune responses of cancer cells are not clear. Cancer immunoresistance and immune escape are major obstacles in immunotherapy. In the present studies, we examined the effects of chemopreventive agents, paclitaxel, etoposide and 5-fluorouracil, on the surface expression of programmed death-1-ligand 1 (PD-L1), a negative regulator of T cell anti-tumor immunity. Interaction of PD-L1 on cancer cells with programmed death receptor 1 (PD-1) on T cells has been reported to inhibit the proliferation of tumor-reactive cytotoxic T cells and induce T cell apoptosis, which could be an important mechanism in the development of cancer immunoresistance. We demonstrated that those chemopreventive agents were able to induce PD-L1 surface expression in human breast cancer cells, which then promoted PD-L1-mediated T cell apoptosis. Our studies reveal a potential link between chemotherapy and cancer immunoresistance.     

A novel case of endometrial dedifferentiated adenocarcinoma associated with MLH1 promotor hypermethylation and microsatellite instability

Endometrial dedifferentiated carcinoma is a rare, malignant tumor whose molecular alterations have not been clarified yet. We report a novel case of a 61-year old woman who presented with irregular vaginal bleeding after menopause and a 3?cm uterus mass. Histology revealed endometrial dedifferentiated adenocarcinoma, a rare subtype comprised of undifferentiated adenocarcinoma. The patient still survived 1?year after surgery without chemotherapy and radiotherapy. Immunohistochemistry revealed loss of MLH1/PMS2 expression and retained MSH2/MSH6 expression. Consistently, microsatellite instability was detected indicative of high microsatellite instability (MSI-H). No BRAF V600E, KRAS and POLE mutations were identified. Remarkably, the promoter regions of mutL homolog 1(MLH1) were methylated. Furthermore, several tumor cells were PD-L1 positive in this case with a concentration at the infiltrating tumor edge indicating MSI-H in endometrial dedifferentiated adenocarcinoma is a potential predictive factor for response to immunotherapy targeting the PD-1 or its ligand PD-L1.     

程序性死亡因子1及其配体在脑胶质瘤中的研究进展

脑胶质瘤一直是中枢神经系统肿瘤研究的重点及难点,高级别胶质瘤因其浸润生长快,位置特殊,综合治疗后效果并不理想。肿瘤免疫治疗通过维持肿瘤与免疫系统的平衡,恢复机体抗肿瘤免疫应答,从而限制肿瘤的发生、发展。目前免疫治疗已运用与多种实体瘤中,并取得了令人欣喜的结果,也为脑胶质瘤的治疗提供了新的思路。阻断PD-1/PD-L1是目前肿瘤免疫治疗的热点。本文就PD-1/PD-L1在脑胶质瘤中的研究及治疗进展进行综述。     

PD-L2 is expressed on activated human T cells and regulates their function

T-cell activation and proliferation are regulated by cosignaling adhesion molecules involved in positive or negative signals. Programmed death (PD)-1 is one of immune inhibitory molecules that is expressed in activated T cells and is a promising target for immunotherapy. Both PD-1 ligands, PD-L1 and PD-L2 are expressed on antigen presenting cells (APCs) involved in the dialogue between a T cell and an APC. Here, we analysed the expression of these ligands, especially for PD-L2, on T cells. PD-L2 appears to be expressed on activated CD4 and CD8T cell subsets. Moreover, as PD-1 molecule, PD-L2 engagement at the surface of T cells is able to down-modulate cytokine production and cell proliferation. These observations indicate that PD-L2 is expressed following activation and is involved in the regulation of T cell function, highlighting the level of complexity in the T cell cosignaling network.     

PD-L2 is expressed on activated human T cells and regulates their function

T-cell activation and proliferation are regulated by cosignaling adhesion molecules involved in positive or negative signals. Programmed death (PD)-1 is one of immune inhibitory molecules that is expressed in activated T cells and is a promising target for immunotherapy. Both PD-1 ligands, PD-L1 and PD-L2 are expressed on antigen presenting cells (APCs) involved in the dialogue between a T cell and an APC. Here, we analysed the expression of these ligands, especially for PD-L2, on T cells. PD-L2 appears to be expressed on activated CD4 and CD8T cell subsets. Moreover, as PD-1 molecule, PD-L2 engagement at the surface of T cells is able to down-modulate cytokine production and cell proliferation. These observations indicate that PD-L2 is expressed following activation and is involved in the regulation of T cell function, highlighting the level of complexity in the T cell cosignaling network.     

sTLR4 的研究进展

TLR4 是第一个被发现的哺乳动物的Toll 样受体(TLRs),广泛表达于哺乳动物细胞表面,能识别病原体的入侵,通过识别配体,激活核转录因子kappa B(NF-κB),进而触发炎症反应。近年来,在体液中发现了一种可溶性形式TLR4(sTLR4)。sTLR4 来自TLR4 mRNA 的可变剪切,广泛存在于各种体液中。sTLR4 主要通过与MD鄄2 形成复合体,抑制LPS 信号通路,从而抑制LPS 引起的炎症反应。sTLR4 作为炎症的诊断工具;作为某些炎症的拮抗剂,抑制炎症反应;替代细胞膜上TLR4受体的胞外域,用于研究信号分子与TLR4 的相互作用;作为某些癌症的预后指标。     

Interferon-γ-induced PD-L1 surface expression on human oral squamous carcinoma via PKD2 signal pathway

Many cells located in the tumor microenvironment function to protect or promote the ability of tumor cells to escape immune destruction. Previous studies have shown that programmed death ligand-1 (PD-L1), a ligand of the B7 superfamily, is expressed on a series of human tumors and can inhibit anti-tumor immune responses. Interferon-γ (IFN-γ), a cytokine produced and secreted by inflammatory cells in the tumor microenvironment, is a main stimulator of PD-L1 expression in tumor cells. Making clear the mechanism of IFN-γ induced the expression of PD-L1 on tumor cells that is benefit to find a way to inhibit the function of PD-L1 and improve cancer cell-reactive immune responses. Herein, we have identified protein kinase D isoform 2 (PKD2) as an important regulator of PD-L1 expression on human oral squamous carcinoma cells induced by IFN-γ. IFN-γ induced the expression of PD-L1 and PKD2 in human oral squamous carcinoma Tca8113 in both time and dose dependent manner. The expression of PD-L1 was decreased significantly after PKD2 knockdown with shRNA/siRNA interference or PKD chemical inhibitor following induction with IFN-γ. The apoptosis of CD8(+) T cell which is induced by tumor cells via PD-1/PD-L1 pathway was significantly decreased, as a result, the anti-tumor effects of tumor antigen specific T cell were increased in vivo. Together, these data combined with our previous results, indicate PKD2 as an important target candidate for tumor biotherapy. Inhibition of PKD2 activation not only inhibits PD-L1 expression and promotes an anti-tumor effect, but also decreases drug resistance in chemotherapy.