Abstract：
Chimeric antigen receptor (CAR)-T cell therapy is a powerful adoptive immunotherapy against both B-cell malignancies and some types of solid tumors. Interleukin (IL) -15 is an important immune stimulator that may provide ideal long-term persistent CAR-T cells. However, higher base line or peak serum IL-15 levels are also related to severe toxicity, such as cytokine release syndrome (CRS), graft-versus-host disease (GVHD), and neurotoxicity.
We successfully constructed CD19 specific armored CAR-T cells overexpressing IL-I5 and IL-15 receptor alpha (IL-15Ra). In vitro cell differentiation and viability were monitored by flow cytometry, and an in vivo xenograft mouse models was used to evaluate the anti-tumor efficiency and liver damage of CAR-T cells.
CAR-T cells overexpressing IL-15 alone demonstrated enhanced viability, retarded exhaustion in vitro and superior tumor-inhibitory effects in vivo. However, these tumor-free mice had lower survival rates, with serious liver injuries, as a possible result of toxicity. As expected, CAR-T cells overexpressing IL-15 combined with IL-15Ra had reduced CD132 expression and released fewer cytokines (IFNγ, IL-2 and IL-15) in vitro, as well as had the tendency to improve mouse survival via repressing the growth of tumor cells and keeping livers healthier compared to CAR-IL-15 T cells.
These results indicated the importance of IL-15 in enhancing T cells persistence and IL-15Ra in reducing the adverse effects of IL-15, with superior tumor retardation during CAR-T therapy. This study paves the way for the rapid exploitation of IL-15 in adoptive cell therapy in the future.
We successfully constructed CD19 specific armored CAR-T cells overexpressing IL-I5 and IL-15 receptor alpha (IL-15Ra). In vitro cell differentiation and viability were monitored by flow cytometry, and an in vivo xenograft mouse models was used to evaluate the anti-tumor efficiency and liver damage of CAR-T cells.
CAR-T cells overexpressing IL-15 alone demonstrated enhanced viability, retarded exhaustion in vitro and superior tumor-inhibitory effects in vivo. However, these tumor-free mice had lower survival rates, with serious liver injuries, as a possible result of toxicity. As expected, CAR-T cells overexpressing IL-15 combined with IL-15Ra had reduced CD132 expression and released fewer cytokines (IFNγ, IL-2 and IL-15) in vitro, as well as had the tendency to improve mouse survival via repressing the growth of tumor cells and keeping livers healthier compared to CAR-IL-15 T cells.
These results indicated the importance of IL-15 in enhancing T cells persistence and IL-15Ra in reducing the adverse effects of IL-15, with superior tumor retardation during CAR-T therapy. This study paves the way for the rapid exploitation of IL-15 in adoptive cell therapy in the future.
摘要：
嵌合抗原受体（CAR）-T细胞疗法是针对B细胞恶性肿瘤和某些类型的实体瘤的强大过继免疫疗法。白细胞介素（IL）-15是一种重要的免疫刺激因子，可以提供理想的长期持久性CAR-T细胞。然而,较高的基线或峰值血清IL-15水平也与严重毒性有关，如细胞因子释放综合征（CRS），移植物抗宿主病（GVHD），和神经毒性。
我们成功构建了过表达IL-I5和IL-15受体α（IL-15Ra）的CD19特异性装甲CAR-T细胞。通过流式细胞术监测体外细胞分化和活力，和体内异种移植小鼠模型用于评估CAR-T细胞的抗肿瘤效率和肝损伤。
单独过表达IL-15的CAR-T细胞表现出增强的活力，在体外延迟耗尽和在体内优越的肿瘤抑制作用。然而,这些无瘤小鼠的存活率较低，严重的肝脏损伤,作为毒性的可能结果。不出所料,过表达IL-15与IL-15Ra结合的CAR-T细胞减少了CD132的表达并释放了较少的细胞因子（IFNγ，IL-2和IL-15)体外，与CAR-IL-15T细胞相比，也有通过抑制肿瘤细胞的生长和保持肝脏健康来提高小鼠存活率的趋势。
这些结果表明IL-15在增强T细胞持久性方面的重要性和IL-15Ra在降低IL-15的不良反应方面的重要性，在CAR-T治疗期间具有优异的肿瘤阻滞。本研究为将来IL-15在过继细胞治疗中的快速开发铺平了道路。
我们成功构建了过表达IL-I5和IL-15受体α（IL-15Ra）的CD19特异性装甲CAR-T细胞。通过流式细胞术监测体外细胞分化和活力，和体内异种移植小鼠模型用于评估CAR-T细胞的抗肿瘤效率和肝损伤。
单独过表达IL-15的CAR-T细胞表现出增强的活力，在体外延迟耗尽和在体内优越的肿瘤抑制作用。然而,这些无瘤小鼠的存活率较低，严重的肝脏损伤,作为毒性的可能结果。不出所料,过表达IL-15与IL-15Ra结合的CAR-T细胞减少了CD132的表达并释放了较少的细胞因子（IFNγ，IL-2和IL-15)体外，与CAR-IL-15T细胞相比，也有通过抑制肿瘤细胞的生长和保持肝脏健康来提高小鼠存活率的趋势。
这些结果表明IL-15在增强T细胞持久性方面的重要性和IL-15Ra在降低IL-15的不良反应方面的重要性，在CAR-T治疗期间具有优异的肿瘤阻滞。本研究为将来IL-15在过继细胞治疗中的快速开发铺平了道路。
