不同CD8^+T细胞分化状态对CAR-T实体肿瘤疗效影响的研究进展

T淋巴细胞分化是一个表型和功能不断改变的渐进过程。T细胞不同分化亚群的抗病毒特征已被较为清晰地揭示,然而在抗肿瘤过程中,这些T细胞亚群的作用和功能研究远不够深入,人们对哪些T细胞亚群能在体内有效地杀伤实体肿瘤知之甚少。2017年美国FDA准入了两款抗CD19嵌合型抗原受体T细胞(chimeric antigen receptor modified T cells,CAR-T)产品上市,为难治性淋巴瘤患者带来了希望。而相较之下,CAR-T在实体肿瘤中的临床应用则相对滞后。近年来深入的T细胞分化研究显示,不同阶段的CD8^+T细胞体内外抗肿瘤效应存在较大差异,幼稚CD8^+T细胞在沿着干细胞样记忆型T细胞向终末效应型T细胞分化的系列进程中会逐渐丧失自我更新、增殖存活、再活化能力,但细胞毒作用却显著增强。这种CD8^+T细胞分化中呈现的效应功能与细胞自我更新、增殖和存活能力的负相关关系,可能是导致CAR-T在体外杀伤效能无法准确反映体内抗实体瘤疗效的重要原因。本文就CD8^+T细胞各分化阶段的特征,以体外靶向杀伤能力评估临床CD8^+CAR-T抗实体瘤疗效的局限性,以及针对这一临床问题可能的解决方案进行了综述。

黄芪-莪术对Lewis肺癌小鼠肿瘤血管及肿瘤微环境中CD8^(+)T细胞的影响

目的 通过观察黄芪-莪术对肿瘤血管及肿瘤微环境中CD8^(+)T细胞及IFN-γ的影响,探讨黄芪-莪术促进肿瘤血管正常化的作用及其与调控CD8^(+)T细胞分化和IFN-γ释放的关系。方法 采用Lewis肺癌移植瘤小鼠模型,分为模型组、贝伐单抗组、PD-1抗体组与黄芪-莪术组共4组,每组各10只,分别给予无药溶剂或相应药物,连续14 d。第14天给药后超声造影观测各组小鼠肿瘤组织血流灌注情况,第15天取材经免疫荧光观测肿瘤组织血管结构,流式细胞术检测肿瘤组织中CD8^(+)T细胞情况,酶联免疫吸附试验检测肿瘤组织内免疫因子干扰素-γ(Interferon-γ,IFN-γ)、白介素-2(Interleukin-2,IL-2)及血管内皮生长因子A(Vascular endothelial growth factor A,VEGFA)、促血管生成素-2(Angiopoietin-2,Ang-2)、基质金属蛋白酶-9(Matrix metalloprotein-9,MMP-9)和整合素αvβ3(Intergrin αvβ3)含量,进行统计学分析。结果 与模型组比较,各用药组肿瘤体积增长较为缓慢(P<0.05),而黄芪-莪术组与贝伐单抗组相当,均优于PD-1抗体组(P<0.05)。超声检测显示,与模型组比较,各用药组肿瘤组织内造影剂呈现快进快出,黄芪-莪术组及贝伐单抗组与模型组比较上升支斜率大、达峰时间短,差异有统计学意义(P<0.05),说明血流灌注增速;黄芪-莪术组较PD-1抗体组上升支斜率大、达峰时间短(P<0.05),贝伐单抗组较PD-1抗体组达峰时间短(P<0.05)。免疫荧光检测显示,与模型组比较,各用药组肿瘤组织微血管密度降低、周细胞覆盖率提升(P<0.05)。流式细胞术检测显示,与模型组比较,黄芪-莪术组与PD-1抗体组CD28^(+)TCF^(+)细胞和CD8^(+)IFN-γ^(+)细胞比例均增加(P<0.05),贝伐单抗组较模型组CD28^(+)TCF^(+)细胞和CD8^(+)IFN-γ^(+)细胞比例增加,但差异无统计学意义(P>0.05);与贝伐单抗组比较,黄芪-莪术组升高CD8^(+)IFN-γ^(+)细胞比例更多(P<0.05),PD-1抗体组升高CD28^(+)TCF^(+)细胞比例更多(P<0.05);与PD-1抗体组比较,黄芪-莪术组CD28^(+)TCF^(+)细胞比例较低,CD8^(+)IFN-γ^(+)细胞比例较高,但差异均无统计学意义(P>0.05)。ELISA检测结果显示,与模型组比较,除贝伐单抗组IL-2水平外差异无统计学意义(P>0.05),各用药组肿瘤组织内VEGFA、Ang-2、整合素αvβ3、MMP-9水平均降低(P<0.01),免疫因子IFN-γ、IL-2水平均升高(P<0.05)。结论 黄芪-莪术能促进肿瘤血管正常化,抑制肿瘤生长,其机制可能与其促进肿瘤微环境中CD8^(+)T细胞向CD28^(+)TCF^(+)细胞分化、增加CD8^(+)IFN-γ^(+)细胞比例和IFN-γ含量有关。

Fuzhengpaidu granule regulates immune activation molecules CD38 and human leukocyte antigen-D related on CD4+ and CD8+ T cells in patients with acquired immunodeficiency syndrome/human immunodeficiency virus

OBJECTIVE: To evaluate the effect of Fuzhengpaidu granule (FZPDG) on immune activation molecules CD38 and human leukocyte antigen-D related (HLA-DR) on CD4+ and CD8+ cells in HIV/AIDS patients, and to explore the underlying mechanism of this therapy. METHODS: Plasma changes in CD3+, CD4+, CD8+, CD3+CD4+CD38+, CD3+CD4+HLA-DR+, CD3+ CD8+CD38+, and CD3+CD8+HLA-DR+levels in HIV/ AIDS patients treated with FZPDG for six months were examined by flow cytometry and compared with levels in healthy controls. RESULTS: The clinical trial included 34 outpatients with HIV/AIDS. Before treatment, plasma levels of CD38+ and HLA-DR+ on CD4/CD8 cells were higherthan those in 28 health controls (P<0.05). There were no significant changes in serum levels of CD3+, CD4+, and CD8+ T cells between pretreatment baseline versus after treatment, which were 82.85% ± 5.41% , 14.57% ± 10.31% and 54.55% ± 11.43% before treatment and 79.15% ± 8.21% , 19.96% ± 9.58% and 56.36% ± 11.67% after treatment, respectively (P>0.05). Plasma levels of CD3+ CD4+CD38+and CD3+CD4+HLA-DR+were 2.3%± 2.2% and 7.8%±5.5% before treatment and 1.2%± 0.8% and 2.6%±1.0% after treatment, respectively. Plasma levels of CD3+CD8+CD38+ and CD3+CD8+ HLA-DR+ were 41.4%±13.4% and 17.8%±11.3% beforetreatment,whichchangedto27.1%±10.2%and 3.8%±2.4%aftertreatment,respectively(P<0.05). CONCLUSION: HIV/AIDS patients exhibited an immune activation profile following FZPDG treatment. A potential mechanism of action for FZPDG appears to lie in its ability to up-regulate CD38 and HLA-DR levels on CD4+ T cells, and down-regulate them on CD8+ cells, thereby modulating immune activation of CD4+and CD8+T cells.