在经临床测试的溶瘤腺免疫疗法中，T细胞衔接器的额外表达可将肿瘤浸润的无关T细胞重定向至癌细胞，以增强抗肿瘤免疫力。

Additional expression of T-cell engager in clinically tested oncolytic adeno-immunotherapy redirects tumor-infiltrated, irrelevant T cells against cancer cells to enhance antitumor immunity.

作者信息

Morita Daisuke, Rosewell Shaw Amanda, Biegert Greyson, Porter Caroline, Woods Mae, Vasileiou Spyridoula, Lim Bora, Suzuki Masataka

机构信息

Department of Medicine, Baylor College of Medicine, Houston, TX, USA.

Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital, Houston Methodist Hospital, Houston, TX, USA.

出版信息

J Immunother Cancer. 2024 Dec 9;12(12):e009741. doi: 10.1136/jitc-2024-009741.

DOI:10.1136/jitc-2024-009741

PMID:39653552

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11629014/

Abstract

BACKGROUND

Oncolytic adenoviruses (OAds) are the most clinically tested viral vectors for solid tumors. However, most clinically tested "Armed" OAds show limited antitumor effects in patients with various solid tumors even with increased dosages and multiple injections. We developed a binary oncolytic/helper-dependent adenovirus system (CAdVEC), in which tumors are coinfected with an OAd and a non-replicating helper-dependent Ad (HDAd). We recently demonstrated that a single low-dose CAdVEC expressing interleukin-12, programmed death-ligand 1 blocker, and HSV thymidine kinase safety switch (CAdTrio) induces significant antitumor effects in patients, including complete response. Similar to previous OAd studies, all patients primarily amplified Ad-specific T cells after treatment however, CAdVEC was still able to induce clinical responses even given at a 100-fold lower dose.

METHODS

To address the mechanisms of CAdTrio-mediated antitumor effect in patients, we analyzed patients' samples using Enzyme-linked immunosorbent spot (ELISpot) to measure T-cell specificity and quantitative polymerase chain reaction (qPCR) to measure CAdVEC viral genome copies at tumor sites. We then evaluated potential mechanisms of CAdVEC efficacy in vitro using live-cell imaging. Based on those results, we developed a new CAdVEC additionally expressing a T-cell engager molecule targeting CD44v6 to redirect tumor-infiltrating irrelevant T cells against cancer stem cell populations (CAdTetra) for further improvement of local CAdVEC treatment. We tested its efficacy against different cancer types both in vitro and in vivo including Ad pre-immunized humanized mice.

RESULTS

We found that HDAd-infected cells escape Ad-specific T-cell recognition with enhanced tumor-specific T-cell activity through immunomodulatory transgenes. Since CAdVEC treatment initially amplified Ad-specific T cells in patients, we re-direct these virus-specific T cells to target tumor cells by additionally expressing CD44v6.BiTE from CAdTetra. CAdTetra significantly controlled tumor growth, repolarizing local and systemic responses against cancer cells in both immunologically "hot" and "cold" tumor models and also induced immunologic memory against rechallenged tumors.

CONCLUSIONS

Our results indicate that CAdTetra effectively induces adaptive T-cell responses against cancer cells by using tumor-infiltrating irrelevant T cells.

摘要

背景

溶瘤腺病毒（OAds）是实体瘤临床测试最多的病毒载体。然而，大多数临床测试的“武装”溶瘤腺病毒，即便增加剂量并多次注射，对各种实体瘤患者的抗肿瘤效果仍有限。我们研发了一种二元溶瘤/辅助依赖型腺病毒系统（CAdVEC），其中肿瘤被一种溶瘤腺病毒和一种非复制性辅助依赖型腺病毒（HDAd）共同感染。我们最近证明，单次低剂量表达白细胞介素-12、程序性死亡配体1阻断剂和单纯疱疹病毒胸苷激酶安全开关的CAdVEC（CAdTrio）能在患者中诱导显著的抗肿瘤效果，包括完全缓解。与之前的溶瘤腺病毒研究类似，所有患者在治疗后主要扩增了腺病毒特异性T细胞，然而，即使以低100倍的剂量给予CAdVEC，它仍能诱导临床反应。

方法

为了探究CAdTrio介导的患者抗肿瘤效应机制，我们使用酶联免疫斑点法（ELISpot）分析患者样本以测量T细胞特异性，使用定量聚合酶链反应（qPCR）测量肿瘤部位的CAdVEC病毒基因组拷贝数。然后我们利用活细胞成像在体外评估CAdVEC疗效的潜在机制。基于这些结果，我们研发了一种新的CAdVEC，其额外表达一种靶向CD44v6的T细胞衔接分子，以重定向肿瘤浸润的无关T细胞针对癌症干细胞群体（CAdTetra），从而进一步改善局部CAdVEC治疗。我们在体外和体内测试了其对不同癌症类型的疗效，包括预先用腺病毒免疫的人源化小鼠。

结果

我们发现，通过免疫调节转基因，HDAd感染的细胞逃避了腺病毒特异性T细胞的识别，同时增强了肿瘤特异性T细胞活性。由于CAdVEC治疗最初在患者中扩增了腺病毒特异性T细胞，我们通过从CAdTetra额外表达CD44v6.BiTE，将这些病毒特异性T细胞重定向以靶向肿瘤细胞。CAdTetra显著控制了肿瘤生长，在免疫“热”和“冷”肿瘤模型中使针对癌细胞的局部和全身反应重新极化，并且还诱导了针对再次攻击肿瘤的免疫记忆。