采用嵌合抗原受体T细胞的养生细胞疗法已经彻底改变了某些恶性肿瘤的治疗方式，但在胶质母细胞瘤等实体肿瘤方面的疗效有限，并且面临着安全治疗靶点的匮乏。作为一种替代方法，对肿瘤特异性新抗原的T细胞受体（TCR）改造养生细胞疗法引起了重大的兴奋，但在胶质母细胞瘤中不存在预临床系统严格地模拟这种方法。我们采用单细胞PCR来分离感兴趣的抗原受体，这个抗原指的是在小鼠胶质母细胞瘤模型GL261中先前发现的Imp3D81N新抗原（mImp3）。这个抗原受体被用来生成突变的Imp3-Specific TCR TransgenIC（MISTIC）小鼠，其中所有CD8 T细胞都是特异于mImp3的。通过细胞疗法模型，我们评估了新抗原特异性T细胞的治疗效果，该模型包括将激活的MISTIC T细胞和白介素2转移至淋巴血流贫血的带瘤小鼠。我们采用流式细胞术、单细胞RNA测序以及全外显子和RNA测序来检查治疗反应的因素。我们分离和表征了3x1.1C TCR，它对mImp3显示高亲和力，但没有野生型的交叉反应。为了提供mImp3特异性T细胞的来源，我们制备了MISTIC小鼠。在免疫细胞疗法模型中，激活的MISTIC T细胞输注导致快速的肿瘤内浸润和深远的抗肿瘤效应，在大多数GL261带瘤小鼠中实现了长期治愈。未对养生细胞疗法产生反应的小鼠组表现出保存的新抗原表达，但肿瘤内MISTIC T细胞功能障碍。MISTIC T细胞疗法的疗效在携带异质mImp3表达的肿瘤小鼠中丧失了，在多克隆人类肿瘤的靶向治疗方面显示出了障碍。我们生成并表征了第一种针对临床前胶质瘤模型内源性新抗原的TCR转基因体，并展示了移植新抗原特异性T细胞的治疗潜力。MISTIC小鼠为胶质母细胞瘤中抗肿瘤T细胞反应的基础和翻译研究提供了一个强大的新平台。

Adoptive cellular therapies with chimeric antigen receptor T cells have revolutionized the treatment of some malignancies but have shown limited efficacy in solid tumors such as glioblastoma and face a scarcity of safe therapeutic targets. As an alternative, T cell receptor (TCR)-engineered cellular therapy against tumor-specific neoantigens has generated significant excitement, but there exist no preclinical systems to rigorously model this approach in glioblastoma.We employed single-cell PCR to isolate a TCR specific for the Imp3D81N neoantigen (mImp3) previously identified within the murine glioblastoma model GL261. This TCR was used to generate the Mutant Imp3-Specific TCR TransgenIC (MISTIC) mouse in which all CD8 T cells are specific for mImp3. The therapeutic efficacy of neoantigen-specific T cells was assessed through a model of cellular therapy consisting of the transfer of activated MISTIC T cells and interleukin 2 into lymphodepleted tumor-bearing mice. We employed flow cytometry, single-cell RNA sequencing, and whole-exome and RNA sequencing to examine the factors underlying treatment response.We isolated and characterized the 3×1.1C TCR that displayed a high affinity for mImp3 but no wild-type cross-reactivity. To provide a source of mImp3-specific T cells, we generated the MISTIC mouse. In a model of adoptive cellular therapy, the infusion of activated MISTIC T cells resulted in rapid intratumoral infiltration and profound antitumor effects with long-term cures in a majority of GL261-bearing mice. The subset of mice that did not respond to the adoptive cell therapy showed evidence of retained neoantigen expression but intratumoral MISTIC T cell dysfunction. The efficacy of MISTIC T cell therapy was lost in mice bearing a tumor with heterogeneous mImp3 expression, showcasing the barriers to targeted therapy in polyclonal human tumors.We generated and characterized the first TCR transgenic against an endogenous neoantigen within a preclinical glioma model and demonstrated the therapeutic potential of adoptively transferred neoantigen-specific T cells. The MISTIC mouse provides a powerful novel platform for basic and translational studies of antitumor T-cell responses in glioblastoma.© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.