建立巨细胞病毒特异性干细胞样记忆T细胞体外扩增新体系的实验研究

巨细胞病毒（CMV）感染导致造血干细胞移植相关死亡率明显提高，是亟待解决的重要临床问题。我们前期研发的体外扩增的CMV特异性T细胞（CMV-ST）回输能够治疗移植后CMV感染，但由于输注后T细胞增殖能力弱、体内持久性不足，使CMV-ST治疗起效慢、有效率低。干细胞样记忆T细胞（TSCM）具有强的自我更新和多向分化潜能，以往研究显示提高TSCM比例可增强过继性T细胞抗肿瘤治疗的疗效。而巨细胞病毒特异性TSCM（CMV-TSCM）比例只占健康人T细胞的万分之一，低频率的CMV-TSCM限制了其抗病毒功能的研究及临床应用。因此，本项目通过①建立新型CMV-TSCM高效扩增技术，并实现临床级扩增；②利用体外及人源化HCMV动物模型，证实体外扩增CMV-TSCM体内增殖能力强、具有强抗CMV特性；从而增强过继性CMV-ST抗病毒作用，为CMV-TSCM回输治疗CMV感染，改善患者预后提供技术支撑。

Cytomegalovirus (CMV) infection leads to a significant increase in hematopoietic stem cell transplantation related mortality, which is an important clinical problem to be solved urgently. The adoptive infusion of CMV-specific T cells (CMV-ST) expanded in vitro, which we developed earlier, can treat CMV infection after transplantation, but due to the weak T cell proliferation ability and insufficient persistence in vivo after infusion, the effectiveness of existing CMVST is still low. Stem cell-like memory T cells (TSCM) have strong self-renewal and multi-directional differentiation potential. Increasing the proportion of TSCM in T cells can enhance the efficacy of adoptive T cell antitumor therapy. However, the proportion of cytomegalovirus-specific TSCM (CMV-TSCM) accounts for only one ten thousandth of healthy human T cells. The low frequency of CMV-TSCM has limited its research and clinical application of antiviral functions.This project will plan to ① establish a new cytomegalovirus-specific TSCM (CMV-TSCM) efficient amplification technology; and achieving CMV-TSCM clinical-grade amplification; ② using in vitro and humanized HCMV animal models to confirm the in vitro amplification of CMV -TSCM has stronger HCMV clearance characteristics and can effectively promote endogenous CMVST reconstruction. It is designed to explore effective methods for the efficient expansion of CMV-TSCM in vitro to enhance the antiviral effect of adoptive CMV-ST and provides technical support for transfusing CMV-TSCM to reduce the CMV infection rate after transplantation.