Ogando-Rivas Elizabeth, Castillo Paul, Jones Noah, Trivedi Vrunda, Drake Jeffrey, Dechkovskaia Anjelika, Candelario Kate M, Yang Changlin, Mitchell Duane A
Department of Neurosurgery, Brain Tumor Immunotherapy Program, Preston A. Wells Jr. Center for Brain Tumor Therapy, Lillian S. Wells, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA.
Department of Pediatrics, Division of Pediatric Hematology Oncology, University of Florida, Gainesville, Florida, USA.
Microbiol Immunol. 2022 May;66(5):201-211. doi: 10.1111/1348-0421.12967. Epub 2022 Apr 13.
Adoptive T-cell therapies have been successfully used as prophylaxis or treatment for immunocompromised patients at risk of viral infections or advanced cancers. Unfortunately, for some refractory cancers, they have failed. To overcome this, checkpoint inhibitors are used to rescue immune antitumor responses. We hypothesized that in vitro checkpoint blockade during T-cell stimulation and expansion with messenger RNA (mRNA)-pulsed DCs may enhance the activity of antigen-specific T cells and improve the efficacy of adoptive cellular therapy platforms. Human peripheral blood mononuclear cells were isolated from cytomegalovirus (CMV)-seropositive donors to generate DCs. These were pulsed with CMV matrix phosphoprotein 65 (CMVpp65)-mRNA to educate T cells in coculture for 15 days. Three checkpoint blockade conditions were evaluated (anti-PD1, anti-Tim3, and anti-PD1 + Tim3). IL-2 and antibodies blockades were added every 3 days. Immunophenotyping was performed on Day 0 and Day 15. Polyfunctional antigen-specific responses were evaluated upon rechallenge with CMVpp65 peptides. CMVpp65-activated CD8 T cells upregulate Lag3 and Tim3 (P ≤ 0.0001). Tim3 antibody blockade alone or in combination led to a significant upregulation of Lag3 expression on CD8 pp65Tetramer central memory, effector memory, and terminal effector memory cells re-expressing RA (TEMRA) T cells. This latter T-cell subset uniquely maintains double-positive Tim3/Lag3 expression after checkpoint blockade. By contrast, PD1 blockade had minimal effects on Tim3 or Lag3 expression. In addition, IFN-γ secretion was reduced in T cells treated with Tim3 blockade in a dose-dependent manner (P = 0.004). In this study, we have identified a potential activating component of Tim3 and linkage between Tim3 and Lag3 signaling upon blocking the Tim3 axis during T-cell-antigen-presenting cell interactions that should be considered when targeting immune checkpoints for clinical use.
过继性T细胞疗法已成功用于预防或治疗有病毒感染风险的免疫功能低下患者或晚期癌症患者。不幸的是，对于一些难治性癌症，该疗法失败了。为克服这一问题，人们使用检查点抑制剂来挽救免疫抗肿瘤反应。我们推测，在用信使核糖核酸（mRNA）脉冲树突状细胞（DC）刺激和扩增T细胞期间进行体外检查点阻断，可能会增强抗原特异性T细胞的活性，并提高过继性细胞治疗平台的疗效。从巨细胞病毒（CMV）血清反应阳性供体中分离出人外周血单个核细胞以生成DC。用CMV基质磷蛋白65（CMVpp65）-mRNA对这些DC进行脉冲处理，以便在共培养中培养T细胞15天。评估了三种检查点阻断条件（抗PD1、抗Tim3和抗PD1 + Tim3）。每3天添加白细胞介素-2和抗体阻断剂。在第0天和第15天进行免疫表型分析。在用CMVpp65肽再次刺激后评估多功能抗原特异性反应。CMVpp65激活的CD8 T细胞上调Lag3和Tim3（P≤0.0001）。单独或联合使用Tim3抗体阻断导致重新表达RA的CD8 pp65四聚体中央记忆、效应记忆和终末效应记忆细胞（TEMRA）T细胞上Lag3表达显著上调。后一个T细胞亚群在检查点阻断后独特地维持双阳性Tim3/Lag3表达。相比之下，PD1阻断对Tim3或Lag3表达影响极小。此外，用Tim3阻断处理的T细胞中干扰素-γ分泌以剂量依赖性方式减少（P = 0.004）。在本研究中，我们确定了Tim3的一种潜在激活成分以及在T细胞与抗原呈递细胞相互作用期间阻断Tim3轴时Tim3与Lag3信号传导之间的联系，在将免疫检查点作为临床应用靶点时应予以考虑。
