靶向CD138的第四代CAR-T细胞的构建及功能研究

该研究构建了靶向CD138的第四代CAR-T细胞(分泌IL-7和CCL19),通过与靶向CD138的第二代CAR-T细胞进行生物学功能比较,探讨第四代CAR-T细胞应用于临床的优势。使用慢病毒转染健康人外周血的T细胞制备出靶向CD138的第二代和第四代CAR-T细胞,CFSE标记法检测T细胞的增殖能力,Transwell实验检测T细胞的趋化能力,ELISA检测细胞因子分泌水平,流式细胞术检测T细胞的CAR表达率和亚型。荧光素酶生物发光法检测CAR-T细胞对多发性骨髓瘤细胞株的体外杀伤功能;构建人多发性骨髓瘤NCG小鼠模型,通过生物发光成像系统监测CAR-T细胞输注后小鼠肿瘤的消退情况。结果显示,靶向CD138的第四代CAR-T细胞(CD138-BBZ-7×19)在体外的生物学功能优于第二代CAR-T细胞(CD138-BBZ),而且在人多发性骨髓瘤动物模型中具有明显的抗肿瘤作用。     

靶向GPC3的第四代嵌合抗原受体T细胞 (分泌IL-7和CCL19) 的构建以及功能

基于嵌合抗原受体修饰的T细胞(CAR-T)的过继免疫疗法已被证明是治疗恶性肿瘤最有希望的策略之一,但是目前其在实体瘤中的应用依然有限。研究表明磷脂酰肌醇蛋白聚糖3 (GPC3)对肝细胞癌来说是一种有意义的诊断、治疗和预后生物标志物,且已有利用第二代/第三代GPC3靶向的CAR-T细胞治疗肝细胞癌的研究报道。为了进一步提高治疗效果,构建同时表达GPC3 CAR、人源IL-7和CCL19细胞因子的第四代慢病毒载体,转染293T细胞包装慢病毒并感染人T淋巴细胞制备靶向GPC3的第四代CAR-T细胞(GPC3-BBZ-7×19)。利用细胞计数、趋化小室、荧光素酶生物发光法以及流式细胞术等比较其与第二代GPC3 CAR-T细胞(GPC3-BBZ)在增殖、迁移、杀伤以及亚型分布方面的区别,评估GPC3-BBZ-7×19 CAR-T细胞对免疫缺陷小鼠体内GPC3阳性的肝细胞癌腹腔移植瘤生长的作用。结果表明与GPC3-BBZ CAR-T细胞相比,GPC3-BBZ-7×19 CAR-T细胞具备更强的增殖能力、趋化能力以及记忆干细胞(Stem memory T cell,Tscm)组成比(P值均0.05),而在体外特异性杀伤GPC3阳性的肝细胞癌细胞以及细胞因子分泌水平方面无显著差异。此外,GPC3-BBZ-7×19 CAR-T细胞能够明显抑制免疫缺陷小鼠体内的GPC3阳性肝细胞癌移植瘤模型。因此靶向GPC3的第四代CAR-T细胞(分泌IL-7和CCL19)有望比第二代GPC3靶向的CAR-T细胞更持久有效地对抗肿瘤,并产生针对肿瘤的记忆功能,为以后的临床试验提供了临床前研究基础。     

肿瘤特异性嵌合抗原受体EGFRvⅢ-CAR的构建及体外活性分析

嵌合抗原受体T细胞免疫疗法（chimeric antigen receptor-T, CAR-T）,是通过体外激活和扩增肿瘤特异或非特异性杀伤细胞达到抗肿瘤效果,在肿瘤免疫治疗方面具有良好的应用前景。本研究构建靶向EGFRⅢ(epidermal growth factor receptor variant III)的嵌合抗原受体（CAR）的重组慢病毒表达载体,利用慢病毒感染并筛选能够稳定表达该嵌合抗原受体的Jurkat细胞系。通过EGFRvⅢ分子刺激、与U87MG细胞共培养的方式检测细胞系的活化状况。结果显示,成功构建了pCDH-EGFRvⅢscFv-CAR-copGFP-T2A-puro慢病毒表达重组质粒,并筛选出可稳定表达EGFRⅢ-CAR的Jurkat 细胞系。CCK-8 法检测显示,EGFRvⅢ分子刺激12 h的Jurkat-CAR细胞增殖率约是对照组的1.36倍（P<0.05）;ELISA法检测显示,与U87MG细胞共孵育后,细胞上清中IL-2的浓度约是单独培养分泌在上清中IL-2的1.625倍（P < 0.01）。以上结果表明,稳定表达CAR的jurkat细胞,可以靶向性识别EGFRvⅢ分子及EGFRvⅢ阳性的靶细胞,并引起IL-2细胞因子释放,为后续临床细胞免疫治疗提供了理论基础。     

靶向抑制表皮生长因子受体EGFR逆转骨肉瘤恶性生物学行为研究

该研究探讨应用表达重组抗表皮生长因子受体三型变异体(EGFRvⅢ)的单链可变区片段(scFv)抗体的重组腺病毒感染骨肉瘤细胞,靶向抑制EGFRvⅢ活性后,骨肉瘤恶性生物学行为的变化情况。收获重组腺病毒,感染骨肉瘤细胞143B、MG63、TE85,靶向抑制EGFRvⅢ活性;体外通过MTT、结晶紫染色、划痕实验、细胞吸附、细胞Matrigel迁移等实验探讨骨肉瘤细胞增殖、黏附、迁移、侵袭等肿瘤恶性生物学行为的变化情况。体内通过感染骨肉瘤动物模型,靶向抑制EGFRvⅢ活性后,应用Xenogen imaging成像技术分析对肿瘤生长的影响。体外实验结果示,靶向抑制骨肉瘤EGFRvⅢ活性,可以明显下调肿瘤细胞的增殖、黏附、迁移、侵袭能力,逆转肿瘤恶性生物学行为;体内实验结果示,靶向抑制骨肉瘤EGFRvⅢ活性,可明显下调肿瘤细胞的增殖生长能力。靶向抑制EGFRvⅢ活性可能逆转骨肉瘤恶性生物学行为,其可能成为骨肉瘤治疗中极有希望的新靶点。     

稳定表达CD19-FLUC-GFP的CT26细胞系的构建及鉴定

实体瘤缺乏明确的嵌合抗原受体T细胞(chimeric antigen receptor T-cell, CAR-T)治疗靶点。因此,通过慢病毒将已经明确的靶点分子CD19带入实体瘤细胞系,研究CD19 CAR-T细胞对其的杀伤,能够为CAR-T细胞针对实体瘤的治疗提供潜在的支撑。本研究利用三质粒慢病毒系统构建了稳定表达CD19、萤火虫荧光素酶(firefly luciferase, FLUC)和绿色荧光蛋白(green fluorescent protein, GFP)的结肠癌CT26细胞系CT26-CD19-FLUC-GFP。该细胞系与CT26细胞系的生长活性一致。通过流式细胞术检测不同代次CT26-CD19-FLUC-GFP细胞,证实了CT26-CD19-FLUC-GFP细胞连续传代至第5、10、22代后CD19及GFP的稳定表达。进一步证实,连续传代至第22代的CT26-CD19-FLUC-GFP细胞中的CD19 mRNA及FLUC表达水平显著高于对照组CT26细胞。与T细胞相比,CD19 CAR-T细胞能够显著杀伤CT26-CD19-FLUC-GFP细胞及MC38-CD19细胞。CT26-CD19-FLUC-GFP细胞腹腔植入小鼠体内1周后,通过活体成像仪可以检测到腹腔区域的FLUC表达。上述结果表明,成功构建了稳定表达CD19-FLUC-GFP的CT26细胞系,且该细胞系能够被CD19 CAR-T细胞特异性杀伤。     

EGF受体Ⅲ型突变体在肿瘤治疗中的研究进展

EGFRⅢ型变异体(或EGFRvⅢ)是一种新型的肿瘤特异性靶点。EGFRvⅢ是正常分子经过遗传学重排成为肿瘤特异性靶点的最好例证。由于仅在肿瘤细胞中发现EGFRvⅢ,可以应用它设计靶向性药物选择性治疗肿瘤,而不影响正常细胞,避免传统治疗中所见的副作用。以表达EGFRvⅢ的细胞为靶点的治疗方式有三种:1)作为毒性抗体或修饰病毒的直接靶点,2)利用EGFRvⅢmRNA的特异性核酶或EGFRvⅢ及其下游信号传导分子的特异性抑制剂进行治疗,3)利用EGFRvⅢ触发免疫反应。概括介绍了肿瘤特异性标记物EGFRvⅢ在肿瘤治疗中的研究进展。     

靶向CS1的CAR-T细胞构建及其抗肿瘤活性的体外研究

文中利用基因工程方法构建包含4-1BB或ICOS的第二代Anti-CS1慢病毒表达载体,以及同时包含这两个共刺激因子的第三代Anti-CS1慢病毒表达载体,通过制备相应慢病毒感染人CD3+T细胞,分别获得靶向CS1的第二代和第三代CAR-T细胞。研究结果表明：以ICOS为共刺激因子及以4-1BB为共刺激因子的第二代CAR-T抗肿瘤活性相似,且在效靶比为1︰1时,含ICOS共刺激因子比含4-1BB共刺激因子的第二代CAR-T细胞对IM9-lucgfp细胞的杀伤效力更高;在效靶比为1︰1、2︰1和5︰1时,第三代CAR-T细胞对IM9-lucgfp细胞的杀伤效力低于第二代;在效靶比为10︰1时,二代和三代CAR-T细胞对IM9-lucgfp细胞的杀伤效力都达到85%以上, 显著高于对照组。综上所述,该研究成功构建了靶向CS1的第二代和第三代CAR-T细胞,其可高效杀伤高表达CS1的肿瘤细胞,且靶向CS1的第二代CAR-T细胞比第三代对肿瘤细胞的杀伤效力更强。     

靶向HER2的CAR-T细胞构建与抗肿瘤活性的体外分析

CAR-T细胞疗法通过靶向识别肿瘤细胞表面抗原,特异性杀伤肿瘤细胞,近年来已经成为肿瘤免疫疗法的研究热点。通过基因工程方法构建靶向人类表皮生长因子受体2(HER2)的CAR慢病毒表达质粒,以磷酸钙沉淀辅助多质粒共转染HEK293T细胞包装,制备CAR慢病毒颗粒lenti-car,感染人外周血单核细胞获得HER2靶向的CAR-T细胞,并分析其对HER2阳性和阴性肿瘤细胞的特异性抑制效果。研究结果表明,构建的CAR-T细胞可被HER-2阳性的肿瘤细胞特异性激活,分泌大量炎症性细胞因子IFN-γ和IL-2。在同样效靶比等处理条件下,构建的HER2靶向CAR-T细胞对HER2阳性的人卵巢癌细胞株SK-OV-3的生长抑制率为(58.47±1.72)%,显著高于对照组(P0.05);而对HER2阴性的人慢性髓原白血病细胞株K562的生长抑制率为(11.74±2.37)%,与对照组无显著差异(P0.05)。进一步,在K562细胞中转染人HER2表达载体使其成为HER2阳性,则HER2靶向CAR-T细胞对其的生长抑制率上升为(30.41±7.59)%,较HER2阴性K562具有明显差异(P0.05)。研究结果表明,构建的HER2靶向的第二代CAR-T细胞可选择性地抑制高表达HER2蛋白的肿瘤细胞的生长,暗示了其对HER2阳性肿瘤进行细胞免疫治疗的临床应用前景。     

低温电转联合Sleeping beauty转座子系统增强CAR-T修饰效率

嵌合抗原受体T淋巴细胞(chimeric antigen receptor T cells, CAR-T cells)在恶性B淋巴细胞瘤治疗上取得了显著成效。CAR-T治疗通过分离病人外周血单个核细胞PBMC,经适当的基因编辑手段表达CAR结构,令T细胞获得靶向肿瘤细胞的能力,扩增后过继到体内完成对肿瘤的杀伤。该文主要探索在低温状态将含有睡美人(Sleeping beauty)转座子/转座酶系统的质粒电转进PBMC内表达CD19-CAR制备CAR-T细胞,并添加特定细胞因子进行增殖,并验证CAR表达、细胞活性与杀伤能力。结果表明,转染效率高达58.8%±4.1%,增殖后的CAR-T细胞能够整合并表达CAR基因,在与靶细胞共培养后,表现出与慢病毒制备的CD19-CAR相似的细胞活性和毒性。该文确定了一种基于Sleeping beauty转座子/转座酶和电转制备CAR-T细胞的方法,为临床CAR-T治疗提供了新的思路。     

EGFRvⅢ胞外区基因重组腺病毒的构建及单域抗体的制备北大核心CSCD

本研究旨在构建能够表达人表皮生长因子EGFRvⅢ胞外区基因的重组腺病毒,并通过免疫骆驼构建噬菌体单域抗体库,筛选和制备EGFRvⅢ胞外区特异性单域抗体并对其进行鉴定。从人前列腺癌细胞系PC-3细胞中提取总RNA,反转录为cDNA,以cDNA为模板扩增EGFRvⅢ胞外区基因,并连接pAdTrack-CMV质粒载体,转化含有pAdEasy-1的大肠杆菌(Escherichia coli)BJ5183感受态细胞,获得同源重组质粒转染HEK293A细胞,得到表达EGFRvⅢ胞外区蛋白的重组腺病毒。利用重组腺病毒免疫双峰驼,构建EGFRvⅢ胞外区特异性噬菌体单域抗体库,并以EGFRvⅢ蛋白为筛选抗原,对其进行筛选,对筛选得到的单域抗体进行诱导表达、纯化及鉴定。结果表明获得了表达EGFRvⅢ胞外区基因的重组腺病毒。构建得到的EGFRvⅢ特异性噬菌体单域抗体库的库容为1.4×109;经过3轮富集和筛选,通过噬菌体ELISA筛选出31个与EGFRvⅢ胞外区蛋白结合的阳性克隆,并对OD450值较高的重组单域抗体E14进行了表达和纯化。经ELISA鉴定,重组单域抗体E14可与EGFRvⅢ胞外区蛋白产生抗原抗体结合反应,具有较高的亲和力。说明制备的EGFRvⅢ特异性噬菌体单域抗体库具有较高的库容和多样性,且筛选得到的单域抗体具有较高的抗原活性和免疫学反应性,为今后以EGFRvⅢ为靶点的恶性肿瘤的诊断和治疗提供新的实验依据。     

靶向人源BCMA的嵌合抗原受体T细胞构建及体外抗肿瘤活性研究

摘要 目的：通过对CAR结构的ScFv单链可变区进行改造,构建并筛选具有更强杀伤肿瘤细胞功能的新型靶向人源B细胞成熟抗原（BCMA）的嵌合抗原受体 (CAR)-T细胞。方法：构建靶向人源BCMA的CAR分子,用逆转录病毒载体包装成功后转导健康志愿者的T细胞,制备Anti-BCMA-CAR-T细胞。将Anti-BCMA-CAR-T细胞作为观察组,普通T细胞作为对照组,将其与RPMI-8226细胞共培养,采用CFSE染色的T细胞增殖实验观察两组体外增殖能力。采用荧光素酶化学发光实验检测两组细胞在不同效靶比（1:8、1:4、1:2、1:1、2:1、4:1）对RPMI-8226细胞的杀伤效率,采用流式细胞术检测两组细胞在不同效靶比（1:4、1:2、1:1、2:1、4:1）对RPMI-8226细胞的杀伤效率。结果：CFSE检测结果显示,与对照组比较,观察组FITC信号明显左移,表明T细胞增殖能力越强。流式细胞术检测结果显示,相同效靶比时,观察组对RPMI-8226细胞的杀伤效率均高于对照组（P均<0.05）;荧光素酶化学发光实验结果显示,相同效靶比时,观察组对RPMI-8226细胞的杀伤效率均高于对照组（P均<0.05）。在效靶比为4:1时,CAR170-T（未经改造的传统的ScFv）细胞和CAR174-T（经改造的ScFv）细胞的杀伤效率分别达到了88.5±0.3 %和98.5±0.7 %。结论：通过对CAR结构的ScFv单链可变区进行改造后成功构建出的新型靶向BCMA的CAR-T细胞,它能保持较强的增殖活性且具有更强的杀伤肿瘤细胞的能力。     

CD19 chimeric antigen receptor–redirected T cells combined with epidermal growth factor receptor pathway substrate 8 peptide–derived dendritic cell vaccine in leukemia

BackgroundChimeric antigen receptor (CAR)–T cell therapy opens a new era for cancer treatment. However, in prolonged follow-up, relapse has emerged as one of the major obstacles. Dendritic cell (DC) vaccination is a promising treatment to eradicate tumor cells and prevent relapse. The epidermal growth factor receptor (EGFR) pathway substrate 8 (Eps8) gene is involved in regulating cancer progression and is considered an attractive target for specific cancer immunotherapy. The purpose of this study was to explore a combinatorial therapy using CAR-T cells and a DC vaccine such as Eps8-DCs to increase leukemia treatment efficacy.MethodsWe pulsed DCs with Eps8-derived peptides to generate Eps8-DCs, engineered T cells to express a second-generation CAR specific for CD19, and analyzed the effects of the Eps8-DCs on the in vitro expansion, phenotype and effector functions of the CD19 CAR-T cells.ResultsThe Eps8-DCs significantly reduced the activation-induced cell death and enhanced the proliferative potential of CAR-T cells during in vitro expansion. In addition, the expanded T cells co-cultured with the Eps8-DCs exhibited an increased percentage of central memory T cells (Tcms) and a decreased percentage of effector memory T cells (Tems). The Eps8-DCs enhanced CD19 CAR-T cell immune functions, including cytokine production, CD107a degranulation activity and cytotoxicity.DiscussionThis study demonstrates that Eps8-DCs exert synergistic effect on CD19 targeting CAR-T cells and paves the way for clinical trials using the combination of DC vaccination and engineered T cells in relapsed leukemia.     

趋化因子CCL11-糖胺聚糖-趋化因子受体CCR3的相互作用研究

目的 探究趋化因子CCL11与受体CCR3、糖胺聚糖（glycosaminoglycans，GAGs）相互作用过程及机制，为深入阐明CCL11-GAGs-CCR3相互作用关系提供理论参考。方法 利用基因工程技术，构建筛选了CCR3-EGFP单分子表达水平的CHO稳转细胞系，利用全内反射荧光成像（total internal reflection fluorescence，TIRF）与等温滴定量热（isothermal titration calorimetry，ITC）技术研究了不同体外溶液条件下GAGs与CCL11的相互作用，并利用趋化实验及活细胞单分子成像实验考察了GAGs-CCL11对CCR3-EGFP稳转细胞趋化行为的调控及CCR3-EGFP在细胞膜上聚集状态的影响。结果 随着硫酸软骨素链长度的增加，其与CCL11结合放热增多，表明其相互作用力增强，其促进CCL11聚集作用增强。单分子荧光成像技术结合趋化试验研究发现，不同种类及不同比例的GAGs均会影响CCL11与CCR3的相互作用，GAGs的加入，抑制了CCL11对CCR3-EGFP稳转细胞的趋化效应及促CCR3-EGFP聚集的能力，且随着硫酸软骨素分子质量的增加，抑制作用显著增强。结论 GAGs的存在可以显著调控CCL11的聚集状态，进而影响其与受体CCR3的相互作用，本研究为进一步阐明CCL11-GAGs-CCR3相互作用关系提供了一定的实验基础。     

Bicistronic CAR-T cells targeting CD123 and CLL1 for AML to reduce the risk of antigen escape

PurposeAcute myeloid leukemia (AML) is a highly heterogeneous neoplastic disease with a poor prognosis that relapses even after its treatment with chimeric antigen receptor (CAR)-T cells targeting a single antigen. CD123 and CLL1 are expressed in most AML blasts and leukemia stem cells, and their low expression in normal hematopoietic stem cells makes them ideal targets for CAR-T. In this study, we tested the hypothesis that a new bicistronic CAR targeting CD123 and CLL1 can enhance antigenic coverage and prevent antigen escape and subsequent recurrence of AML.MethodsCD123 and CLL1 expressions were evaluated on AML cell lines and blasts. Then, in addition to concentrating on CD123 and CLL1, we introduced the marker/suicide gene RQR8 with a bicistronic CAR. Xenograft models of disseminated AML and in vitro coculture models were used to assess the anti-leukemia efficacy of CAR-T cells. The hematopoietic toxicity of CAR-T cells was evaluated in vitro by colony cell formation assays. It was demonstrated in vitro that the combination of rituximab and NK cells caused RQR8-mediated clearance of 123CL CAR-T cells.ResultsWe have successfully established bicistronic 123CL CAR-T cells that can target CD123 and CLL1. 123CL CAR-T cells effectively cleared AML cell lines and blasts. They also demonstrated appreciable anti-AML activity in animal transplant models. Moreover, 123CL CAR-T cells can be eliminated in an emergency by a natural safety switch and don't target hematopoietic stem cells.ConclusionsThe bicistronic CAR-T cells targeting CD123 and CLL1 may be a useful and secure method for treating AML.     

EGFRvIII expression triggers a metabolic dependency and therapeutic vulnerability sensitive to autophagy inhibition

Expression of EGFRvIII is frequently observed in glioblastoma and is associated with increased cellular proliferation, enhanced tolerance to metabolic stresses, accelerated tumor growth, therapy resistance and poor prognosis. We observed that expression of EGFRvIII elevates the activation of macroautophagy/autophagy during starvation and hypoxia and explored the underlying mechanism and consequence. Autophagy was inhibited (genetically or pharmacologically) and its consequence for tolerance to metabolic stress and its therapeutic potential in (EGFRvIII⁺) glioblastoma was assessed in cellular systems, (patient derived) tumor xenopgrafts and glioblastoma patients. Autophagy inhibition abrogated the enhanced proliferation and survival advantage of EGFRvIII⁺ cells during stress conditions, decreased tumor hypoxia and delayed tumor growth in EGFRvIII⁺ tumors. These effects can be attributed to the supporting role of autophagy in meeting the high metabolic demand of EGFRvIII⁺ cells. As hypoxic tumor cells greatly contribute to therapy resistance, autophagy inhibition revokes the radioresistant phenotype of EGFRvIII⁺ tumors in (patient derived) xenograft tumors. In line with these findings, retrospective analysis of glioblastoma patients indicated that chloroquine treatment improves survival of all glioblastoma patients, but patients with EGFRvIII⁺ glioblastoma benefited most. Our findings disclose the unique autophagy dependency of EGFRvIII⁺ glioblastoma as a therapeutic opportunity. Chloroquine treatment may therefore be considered as an additional treatment strategy for glioblastoma patients and can reverse the worse prognosis of patients with EGFRvIII⁺ glioblastoma.     

Cell differentiation dependent expressed CCR6 mediates ERK-1/2, SAPK/JNK, and Akt signaling resulting in proliferation and migration of colorectal cancer cells

The expression of CCL20 (MIP-3alpha), which chemoattracts leukocytes to sites of inflammation, has been shown in intestinal epithelial cells (IEC). Aim of this study was to analyze the role of the CCL20 receptor CCR6 in IEC and colorectal cancer (CRC) cells. Expression of CCR6 and CCL20 was analyzed by RT-PCR and immunohistochemistry. Signaling was investigated by Western blotting, proliferation by MTS assays and chemotactic cell migration by wounding assays. The effect of CCL20 on Fas-induced apoptosis was determined by flow cytometry. CCR6 and its ligand CCL20 are expressed in IEC. Moreover, CRC and CRC metastases express CCR6, which is upregulated during IEC differentiation. Stimulation of IEC with CCL20 and proinflammatory stimuli (TNF-alpha, IL-1beta, LPS) significantly upregulates CCL20 mRNA expression. CCL20 expression was significantly increased in inflamed colonic lesions in Crohn's disease and correlated significantly with the IL-8 mRNA expression in these lesions (r = 0.71) but was downregulated in CRC metastases. CCL20 activated Akt, ERK-1/2, and SAPK/JNK MAP kinases and increased IL-8 protein expression. The CCL20 mediated activation of these pathways resulted in a 2.6-fold increase of cell migration (P = 0.001) and in a significant increase of cell proliferation (P < 0.05) but did not influence Fas-induced apoptosis. In conclusion, IEC and CRC express CCL20 and its receptor CCR6. CCL20 expression is increased in intestinal inflammation, while CCR6 is upregulated during cell differentiation. CCR6 mediated signals result in increased IEC migration and proliferation suggesting an important role in intestinal homeostasis and intestinal inflammation by mediating chemotaxis of IEC but also in mediating migration of CRC cells.     

Micro-hydrogel injectables that deliver effective CAR-T immunotherapy against 3D solid tumor spheroids

Chimeric antigen receptor (CAR-) T cells are revolutionizing cancer treatment, as a direct result of their clinical impact on the treatment of hematological malignancies. However for solid tumors, CAR-T cell therapeutic efficacy remains limited, primarily due to the complex immunosuppressive tumor microenvironment, inefficient access to tumor cells and poor persistence of the killer cells. In this in vitro study, an injectable, gelatin-based micro-hydrogel system that can encapsulate and deliver effective CAR-T therapy is investigated. CAR-T cells targeting TAG-72, encapsulated in these microgels possessed high viability (> 87%) after 7 days, equivalent to those grown under normal expansion conditions, with retention of the T cell phenotype and functionality. Microgel recovered CAR-T cells demonstrated potent on-target cytotoxicity against human ovarian cancer in vitro and on three-dimensional tumor spheroids, by completely eliminating tumor cells. The gelatin-based micro-hydrogels have the potential to serve as carrier systems to augment CAR-T immunotherapeutic treatment of solid tumors.     

The progress and perspectives of CAR-T cell therapy

CAR-T cell therapy has already achieved world-renowned clinical effects in the treatment of hematological malignancies. Due to the tumor heterogeneity, immunosuppressive microenvironment, and other factors, CAR-T cell therapy has still not shown obvious clinical efficacy in clinical treatment of solid tumors. However, great progress has been made in the preparation of CAR-T cells in recent years, including T cells redirected for universal cytokine mediated killing, universal CAR -T cells, non-viral vector CAR-T cells, SynNotch technology, SUPRA CAR technology, regulated CAR-T cells, and bi-specific CAR-T cells, etc. Future research and development of CAR-T cell therapy will be focused on these following aspects: the combined application of CAR-T cells with different targets, known as "Cocktail CAR-T cells", is expected to increase efficiency toward solid tumors; based on systemic biology/synthetic biology theories, CAR-T cells are likely to be transformed to robot or intelligent system by introducing sensors, logic gates, and logic circuits. This article mainly comments on research progress and perspectives on CAR-T cell therapy in solid tumor treatment.