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Updated: Dec 23, 2025
Paramyxoviruses for Tumor-targeted Immunomodulation: Design and Evaluation Ex Vivo
Published on: January 7, 2019
Oncolytic adenovirus ORCA-010 increases the type 1 T cell stimulatory capacity of melanoma-conditioned dendritic
M López González1, R van de Ven1,2, H de Haan1
1Department of Medical Oncology, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam, the Netherlands.
Abstract:
Immune checkpoint blockade has resulted in durable responses in patients with metastatic melanoma, but only in a fraction of treated patients. For immune checkpoint inhibitors (ICI) to be effective, sufficient infiltration with tumor-reactive T cells is essential. Oncolytic viruses (OV) selectively replicate in and lyse tumor cells and so induce an immunogenic form of cell death, providing at once a source of tumor-associated (neo)antigens and of danger signals that together induce effective T cell immunity and tumor infiltration. Melanoma-associated suppression of dendritic cell (DC) differentiation effectively hampers OV- or immune checkpoint inhibitor (ICI)-induced anti-tumor immunity, due to a consequent inability to prime and attract anti-tumor effector T cells. Here, we set out to study the effect of ORCA-010, a clinical stage oncolytic adenovirus, on DC differentiation and functionality in the context of human melanoma. In melanoma and monocyte co-cultures, employing a panel of five melanoma cell lines with varying origins and oncogenic mutation status, we observed clear suppression of DC development with apparent skewing of monocyte differentiation to a more M2-macrophage-like state. We established the ability of ORCA-010 to productively infect and lyse the melanoma cells. Moreover, although ORCA-010 was unable to restore DC differentiation, it induced activation and an increased co-stimulatory capacity of monocyte-derived antigen-presenting cells. Their subsequent ability to prime effector T cells with a type I cytokine profile was significantly increased in an allogeneic mixed leukocyte reaction. Our findings suggest that ORCA-010 is a valuable immunotherapeutic agent for melanoma.
Insights
Oncolytic adenovirus ORCA-010 lyses melanoma cells and enhances anti-tumor immunity by activating antigen-presenting cells, suggesting its potential as an effective melanoma immunotherapy.
Area of Science:
- Immunology
- Oncology
- Virology
Background:
- Immune checkpoint inhibitors (ICIs) show durable responses in metastatic melanoma but require T cell infiltration for efficacy.
- Oncolytic viruses (OVs) induce immunogenic cell death, providing antigens and danger signals to promote T cell immunity.
- Melanoma suppresses dendritic cell (DC) differentiation, hindering anti-tumor immunity crucial for OV and ICI therapies.
Purpose of the Study:
- To investigate the impact of the oncolytic adenovirus ORCA-010 on dendritic cell (DC) differentiation and function in human melanoma.
- To assess ORCA-010's ability to overcome melanoma-associated DC suppression and enhance anti-tumor immune responses.
Main Methods:
- Co-culture of five human melanoma cell lines with monocytes.
- Treatment with ORCA-010, a clinical-stage oncolytic adenovirus.
- Assessment of DC differentiation, monocyte polarization, and antigen-presenting cell (APC) activation.
- Evaluation of T cell priming capacity using allogeneic mixed leukocyte reactions.
Main Results:
- Melanoma co-cultures showed suppressed DC development and M2-macrophage skewing.
- ORCA-010 productively infected and lysed melanoma cells.
- ORCA-010 did not restore DC differentiation but activated monocyte-derived APCs, enhancing their co-stimulatory capacity.
- ORCA-010 significantly increased the ability of APCs to prime effector T cells with a type I cytokine profile.
Conclusions:
- ORCA-010 effectively lyses melanoma cells and enhances anti-tumor immunity by activating antigen-presenting cells.
- Despite not restoring DC differentiation, ORCA-010 promotes T cell priming, indicating its potential as a melanoma immunotherapy.
- ORCA-010 represents a promising immunotherapeutic strategy for melanoma treatment.
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