Recombinant viruses with other anti-cancer therapeutics: a step towards advancement of oncolytic virotherapy

Engineering Non-Human RNA Viruses for Cancer Therapy

Alongside the development and progress in cancer immunotherapy, research in oncolytic viruses (OVs) continues advancing novel treatment strategies to the clinic. With almost 50 clinical trials carried out over the last decade, the opportunities for intervention using OVs are expanding beyond the old-fashioned concept of "lytic killers", with promising breakthrough therapeutic strategies focused on leveraging the immunostimulatory potential of different viral platforms. This review presents an overview of non-human-adapted RNA viruses engineered for cancer therapy. Moreover, we describe the diverse strategies employed to manipulate the genomes of these viruses to optimize their therapeutic capabilities. By focusing on different aspects of this particular group of viruses, we describe the insights into the promising advancements in the field of virotherapy and its potential to revolutionize cancer treatment.

A combined immunopeptidomics, proteomics, and cell surface proteomics approach to identify immunotherapy targets for diffuse intrinsic pontine glioma

Introduction

Diffuse intrinsic pontine glioma (DIPG), recently reclassified as a subtype of diffuse midline glioma, is a highly aggressive brainstem tumor affecting children and young adults, with no cure and a median survival of only 9 months. Conventional treatments are ineffective, highlighting the need for alternative therapeutic strategies such as cellular immunotherapy. However, identifying unique and tumor-specific cell surface antigens to target with chimeric antigen receptor (CAR) or T-cell receptor (TCR) therapies is challenging.

Methods

In this study, a multi-omics approach was used to interrogate patient-derived DIPG cell lines and to identify potential targets for immunotherapy.

Results

Through immunopeptidomics, a range of targetable peptide antigens from cancer testis and tumor-associated antigens as well as peptides derived from human endogenous retroviral elements were identified. Proteomics analysis also revealed upregulation of potential drug targets and cell surface proteins such as Cluster of differentiation 27 (CD276) B7 homolog 3 protein (B7H3), Interleukin 13 alpha receptor 2 (IL-13Rα2), Human Epidermal Growth Factor Receptor 3 (HER2), Ephrin Type-A Receptor 2 (EphA2), and Ephrin Type-A Receptor 3 (EphA3).

Discussion

The results of this study provide a valuable resource for the scientific community to accelerate immunotherapeutic approaches for DIPG. Identifying potential targets for CAR and TCR therapies could open up new avenues for treating this devastating disease.

Transposable elements potentiate radiotherapy-induced cellular immune reactions via RIG-I-mediated virus-sensing pathways

Radiotherapy (RT) plus immunotherapy is a promising modality; however, the therapeutic effects are insufficient, and the molecular mechanism requires clarification to further develop combination therapies. Here, we found that the RNA virus sensor pathway dominantly regulates the cellular immune response in NSCLC and ESCC cell lines. Notably, transposable elements (TEs), especially long terminal repeats (LTRs), functioned as key ligands for the RNA virus sensor RIG-I, and the mTOR-LTR-RIG-I axis induced the cellular immune response and dendritic cell and macrophage infiltration after irradiation. Moreover, RIG-I-dependent immune activation was observed in ESCC patient tissue. scRNA sequencing and spatial transcriptome analysis revealed that radiotherapy induced the expression of LTRs, and the RNA virus sensor pathway in immune and cancer cells; this pathway was also found to mediate tumour conversion to an immunological hot state. Here, we report the upstream and ligand of the RNA virus sensor pathway functions in irradiated cancer tissues.

Real-time monitoring of oncolytic VSV properties in a novel in vitro microphysiological system containing 3D multicellular tumor spheroids

As a new class of cancer therapeutic agents, oncolytic viruses (OVs) have gained much attention not only due to their ability to selectively replicate in and lyse tumor cells, but also for their potential to stimulate antitumor immune responses. As a result, there is an increasing need for in vitro modeling systems capable of recapitulating the 3D physiological tumor microenvironment. Here, we investigated the potential of our recently developed microphysiological system (MPS), featuring a vessel-like channel to reflect the in vivo tumor microenvironment and serving as culture spaces for 3D multicellular tumor spheroids (MCTSs). The MCTSs consist of cancer A549 cells, stromal MRC5 cells, endothelial HUVECs, as well as the extracellular matrix. 3D MCTSs residing in the MPS were infected with oncolytic VSV expressing GFP (oVSV-GFP). Post-infection, GFP signal intensity increased only in A549 cells of the MPS. On the other hand, HUVECs were susceptible to virus infection under 2D culture and IFN-β secretion was quite delayed in HUVECs. These results thus demonstrate that OV antitumoral characteristics can be readily monitored in the MPS and that its behavior therein somewhat differs compared to its activity in 2D system. In conclusion, we present the first application of the MPS, an in vitro model that was developed to better reflect in vivo conditions. Its various advantages suggest the 3D MCTS-integrated MPS can serve as a first line monitoring system to validate oncolytic virus efficacy.