CAR-T细胞免疫疗法的研究进展

 嵌合抗原受体T细胞（chimeric antigen receptor T-cell,CAR-T）免疫治疗可以精准靶向癌细胞,在肿瘤（尤其是淋巴瘤）的临床治疗上表现出良好的效果,是近年来受到广泛关注的一种肿瘤免疫治疗方法。目前CAR-T在淋巴瘤中的应用趋于成熟,但在实体瘤中由于肿瘤微环境等因素导致CAR-T疗法应用受限。本文概述了当前CAR-T免疫疗法面临的挑战及相关机制研究,如靶向肿瘤的特异性、安全性以及CAR-T的持久性等,同时聚焦针对这些挑战对CAR-T的CAR结构设计进行优化的研究进展。     

CAR-T治疗难治/复发B细胞肿瘤患者后继发第二肿瘤2例并文献复习

目的分析基于嵌合抗原受体修饰的T细胞(chimeric antigen receptors-modified T cells,CAR-T)疗法在难治/复发B细胞肿瘤患者治疗中的临床特点及疗效。方法回顾分析2例B细胞肿瘤患者接受CAR-T治疗后继发第二肿瘤的病例资料并复习相关文献。结果1例诊断为滤泡性淋巴瘤,接受CD19及CD22 CAR-T治疗后,无进展生存期为28个月,后继发腺癌;1例诊断为急性B淋巴细胞白血病,接受CD19 CAR-T治疗后,无进展生存期为14个月,后继发急性髓系白血病。结论CAR-T治疗在B细胞肿瘤患者治疗中取得巨大突破,但这一疗法在临床应用中仍存在诱发第二肿瘤等远期不良反应,在临床实践中需要长期随访与总结。     

重组人促血小板生成素在多发性骨髓瘤患者自体外周血干细胞移植中的临床应用

目的探讨重组人促血小板生成素(recombinant human thrombopoietin,rhTPO)在多发性骨髓瘤(multiple myeloma,MM)患者自体外周血干细胞移植(autologous peripheral blood stem cell transplantation,APBSCT)中的临床价值。方法分析2010年1月至2019年12月本中心收集的CD34+自体造血干细胞数目低于2×10^(6)/kg(患者体重)并完成APBSCT的MM患者的临床资料,比较单用粒细胞集落刺激因子(granulocyte colony-stimulating factor,G-CSF)及G-CSF联合rhTPO在APBSCT中促进骨髓造血重建的差异。结果根据APBSCT期间应用造血生长因子的不同,将患者分为G-CSF组(n=39)和G-CSF+rhTPO组(n=53)。两组患者平均CD34+干细胞数量差异无统计学意义(P=0.149),G-CSF+rhTPO组中性粒细胞植入平均时间较G-CSF组缩短[(11.21±1.03)d vs(12.13±1.47)d,P=0.001],血小板植入速度较G-CSF组快[(12.66±2.35)d vs(15.36±5.79)d,P=0.008],平均血小板输注治疗量低于G-CSF组[(1.79±0.77)个治疗量vs(2.46±1.82)个治疗量,P=0.036],总体感染率和3~4级感染率也较G-CSF组低(34.0%vs 41.0%,P=0.041;5.7%vs 23.1%,P=0.001)。结论rhTPO在MM患者APBSCT中起重要作用,与G-CSF联合能加速骨髓造血重建,降低血小板输注量和严重感染发生率。     

Manufacture of Chimeric Antigen Receptor T Cells from Mobilized Cyropreserved Peripheral Blood Stem Cell Units Depends on Monocyte Depletion

Cytotoxic chemotherapy and radiation can render lymphocyte repertoires qualitatively and quantitatively defective. Thus, heavily treated patients are often poor candidates for the manufacture of autologous chimeric antigen receptor (CAR)-T cell products. In the United States and Europe, children with high-risk neuroblastoma undergo apheresis early in the course of treatment to collect peripheral blood stem cells (PBSCs) for cryopreservation in preparation for high-dose chemotherapy followed by autologous stem cell rescue. Here, we investigate whether these cryopreserved chemotherapy and granulocyte colony-stimulating factor (G-CSF)-mobilized PBSCs can serve as starting material for CAR-T cell manufacturing. We evaluated T cell precursor subsets in cryopreserved PBSC units from 8 patients with neuroblastoma using fluorescent activated cell sorting-based analysis. Every cryopreserved unit collected early in treatment contained both CD4 and CD8 precursors with significant numbers of naïve and central memory precursors. Significant numbers of Ki67⁺/PD1⁺ T cells were detected, presumably the result of chemotherapy-induced lymphopenia and subsequent homeostatic proliferation. Cryopreserved PBSC units containing 56 to 112?×?10⁶ T cells were amenable to immunomagnetic selection, CD3?×?28 bead activation, lentiviral transduction, and cytokine-driven expansion, provided that CD14 monocytes were depleted before the initiation of cultures. Second- and third-generation CD171 CAR⁺ CD4 and CD8 effector cells derived from cryopreserved units displayed antineuroblastoma lytic potency and cytokine secretion comparable to those derived from a healthy donor and mediated in vivo antitumor regression in NSG mice. We conclude that cryopreserved PBSCs procured via standard methods during early treatment can serve as an alternative starting source for CAR-T cell manufacturing, extending the options for heavily treated patients.     

Radiation enhances the efficacy of EGFR-targeted CAR-T cells against triple-negative breast cancer by activating NF-κB/Icam1 signaling

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GMP CAR-T cell production

The clinical success achieved using CD19-directed CAR-T cells has stimulated many academic institutions to explore the feasibility of manufacturing these, and other CAR-T cells, in-house. This article reviews the issues that must be addressed in order to achieve this goal. It includes the manufacturing infrastructure, the regulatory environment, practical aspects of production, and the costs involved.     

CAR-T细胞治疗多发性骨髓瘤的研究进展

多发性骨髓瘤（MM）是一种源于骨髓浆细胞的恶性肿瘤,截止目前尚无有效的治愈手段。嵌合抗原受体(CAR)-T细胞疗法是一种具有广阔研究前景的MM治疗方法。其设计理念是通过对部分基因序列进行特异性的改造,使CAR特异性地影响靶向肿瘤细胞的抗原,受体与抗原相结合以激活T细胞杀死肿瘤细胞。本文主要阐述CAR-T细胞疗法的设计过程、研究进展及现阶段所面临的缺陷。     

Homogeneous antibody and CAR-T cells with improved effector functions targeting SSEA-4 glycan on pancreatic cancer

Pancreatic cancer is usually asymptomatic in the early stages; the 5-y survival rate is around 9%; and there is a lack of effective treatment. Here we show that SSEA-4 is more expressed in all pancreatic cancer cell lines examined but not detectable in normal pancreatic cells; and high expression of SSEA-4 or the key enzymes B3GALT5 + ST3GAL2 associated with SSEA-4 biosynthesis significantly lowers the overall survival rate. To evaluate potential new treatments for pancreatic cancer, homogeneous antibodies with a well-defined Fc glycan for optimal effector functions and CAR-T cells with scFv construct designed to target SSEA-4 were shown highly effective against pancreatic cancer in vitro and in vivo. This was further supported by the finding that a subpopulation of natural killer (NK) cells isolated by the homogeneous antibody exhibited enhancement in cancer-cell killing activity compared to the unseparated NK cells. These results indicate that targeting SSEA-4 by homologous antibodies or CAR-T strategies can effectively inhibit cancer growth, suggesting SSEA-4 as a potential immunotherapy target for treating pancreatic disease.

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer. The lack of effective treatment (1–4) along with problems of tumor heterogeneity, complex tumor microenvironment, drug resistance, and lack of early detection (5–7) are the major challenges in development of effective treatment for PDAC. These challenges point to an urgent unmet medical need for identification of new targets for development of early diagnosis and better treatment for this disease. In addition, although a variety of cell surface markers have been explored in the past, most of these markers are also expressed in normal cells or are frequently mutated to resist treatments, making the targeted therapy strategy difficult to achieve effectively (8–11). Altered glycolipids generated by aberrant glycosylation have been recognized as potential anticancer targets (12, 13), especially many tumor-associated carbohydrate antigens (TACA) (13) discovered to date are highly sialylated or fucosylated and often found on the surface of cancer cells and their stem cells (14, 15). Altered glycosylation is a hallmark of tissue inflammation and neoplasia due to differential expression of glycosyltransferases. Compared to proteins, glycans are smaller in size and are synthesized by many glycan-associated enzymes; so when the glycans are assembled abnormally in diseased cells, their structures could become unique and nonself and could be used as markers with more distinct structural difference than proteins (15–18). Among the glycoconjugates of TACA, stage-specific embryonic antigen-4 (SSEA-4) is a cell-surface glycosphingolipid (GSL) used to define human embryonic stem cells (ESCs) and human embryonal carcinoma cells or induced pluripotent stem cells (iPSCs) (19, 20). SSEA-4 usually would disappear after stem cell differentiation and reappear with the other two globo-series GSLs, SSEA-3 and Globo-H (21–24). The importance of globo-series GSLs as unique markers in cancer progression is further supported by the ongoing phase 3 global trial of a Globo-H vaccine against triple-negative breast cancer ({"type":"clinical-trial","attrs":{"text":"NCT03562637","term_id":"NCT03562637"}}NCT03562637). In this study, as part of our efforts to identify new targets for PDAC, we sought to investigate the role of SSEA-4 in cancer patients and found that its high expression correlated with poor survival. In addition, we also showed the development of a homogeneous antibody with improved effector functions and a CAR-T strategy to target SSEA-4 that hold a significant promise for the treatment of PDAC.     

Treatment of pemphigus vulgaris: part 2 – emerging therapies

ABSTRACT

Introduction: Corticosteroids and immunosuppressive agents have been the mainstay for the treatment of pemphigus vulgaris (PV). While they have benefited patients, they have been associated with the risks of prolonged immune suppression and a high incidence of significant and catastrophic side effects. Relapses are common. Novel agents promising targeted therapies, that may provide better outcomes, are being studied.

Areas covered: Recently rituximab with corticosteroids has been recommended as the first-line treatment for PV. A number of known and new therapeutic agents currently investigated are BAFF, P13K, BTK inhibitors along with the use of IVIg and CAR-T therapy. The possible role of these therapeutic targets in the pathophysiology appears to be the rationale for the treatment of this potentially fatal disease.

Expert opinion: While there is significant enthusiasm for these therapies, certain concerns and consequences are being under-discussed. None of the current clinical trials in progress are specific for PV, except possibly CAR-T therapy. The major issue(s) that are unclear is whether these therapies would be successful in providing long-term clinical remissions. Will these therapies require additional agents to be effective? Will the benefits be limited in duration? The answers to many questions will determine their final place in the algorithm for the treatment of PV.