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Paramyxoviruses for Tumor-targeted Immunomodulation: Design and Evaluation Ex Vivo
Published on: January 7, 2019
The oncolytic virus ΔPK has multimodal anti-tumor activity
Laure Aurelian1, Dominique Bollino2, Aric Colunga2
1Department of Microbiology and Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201, USA laurelian@som.umaryland.edu.
Abstract:
Oncolytic viruses (OVs) are an emerging cancer therapeutic, with a near complete absence of serious adverse effects. However, clinical efficacy is relatively modest, related to poor tumor penetration, failure to lyse cancer stem cells (CSCs) and blockade of immunogenic cell death by the immunosuppressive tumor microenvironment. To overcome such limitations, we developed an OV (known as ΔPK) with multimodal anti-tumor activity. ΔPK has potent anti-tumor activity both in melanoma cell lines and xenograft animal models, associated with virus replication and the induction of multiple independent programmed cell death pathways. It lyses CSCs through autophagy modulation and it reverses the immunosuppressive tumor microenvironment by altering the balance of cytokines secreted by the tumor cells. This includes decreased tumor cell secretion of the immunosuppressive and procancerous cytokines IL-10 and IL-18 and concomitant increased secretion of the proinflammatory cytokines TNF-α, GM-CSF, IL-6 and IL-1β. ΔPK also upregulates the NKG2D ligand, MICA expressed by cytotoxic NK and T cells, and downregulates the negative immune checkpoint regulator cytotoxic T-lymphocyte antigen-4 (CTLA-4). ΔPK is well tolerated in human patients in whom it also alters the Th1/Th2 balance. Further studies are designed to elucidate the role of these contributions in different tumor types.
Insights
A novel oncolytic virus (OV), known as ΔPK, demonstrates potent anti-tumor activity by lysing cancer stem cells and reversing the immunosuppressive tumor microenvironment. This emerging cancer therapeutic shows promise with minimal adverse effects in early human trials.
Area of Science:
- Oncology
- Virology
- Immunology
Background:
- Oncolytic viruses (OVs) are a promising cancer therapy with a favorable safety profile.
- Clinical efficacy of OVs is limited by poor tumor penetration, cancer stem cell (CSC) survival, and an immunosuppressive tumor microenvironment.
- Overcoming these limitations is crucial for advancing OV-based cancer treatments.
Purpose of the Study:
- To develop and evaluate a novel oncolytic virus (ΔPK) with enhanced multimodal anti-tumor capabilities.
- To assess ΔPK's efficacy in targeting cancer stem cells and modulating the tumor microenvironment.
- To investigate ΔPK's impact on immune responses, including cytokine profiles and immune checkpoints.
Main Methods:
- Development of a modified oncolytic virus (ΔPK) with enhanced anti-tumor properties.
- In vitro testing in melanoma cell lines and in vivo studies using xenograft animal models.
- Analysis of programmed cell death pathways, autophagy modulation, cytokine secretion profiles, and immune checkpoint expression (CTLA-4, MICA).
- Evaluation of safety and immunomodulatory effects in human patients.
Main Results:
- ΔPK exhibited potent anti-tumor activity in melanoma cell lines and xenograft models, linked to virus replication and induction of multiple cell death pathways.
- ΔPK effectively lysed cancer stem cells via autophagy modulation.
- ΔPK reversed the immunosuppressive tumor microenvironment by decreasing IL-10/IL-18 and increasing TNF-α, GM-CSF, IL-6, and IL-1β secretion.
- ΔPK upregulated MICA and downregulated CTLA-4, enhancing cytotoxic NK and T cell activity.
- ΔPK was well-tolerated in human patients and modulated the Th1/Th2 balance.
Conclusions:
- The novel oncolytic virus ΔPK demonstrates significant multimodal anti-tumor activity.
- ΔPK effectively targets cancer stem cells and reverses the immunosuppressive tumor microenvironment, offering a promising therapeutic strategy.
- ΔPK's favorable safety profile and immunomodulatory effects warrant further investigation in diverse tumor types.
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