Gnostic and agnostic immunotherapy by tropism-retargeted herpes simplex virus without direct tumor treatment

Background Cancer immunotherapy includes vaccines generated through distinct approaches, each with advantages and limitations. Those made of autologous or allogeneic whole cells do not require prior identification of antigens, that is, immunize against undetermined (agnostic) tumor antigens. However...

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Main Authors: Andrea Vannini, Federico Parenti, Cristina Forghieri, Elisabetta Romagnoli, Daniela Massaro, Anna Zaghini, Gabriella Campadelli-Fiume, Tatiana Gianni
Format: Article
Language:English
Published: BMJ Publishing Group 2025-07-01
Series:Journal for ImmunoTherapy of Cancer
Online Access:https://jitc.bmj.com/content/13/7/e011812.full
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author Andrea Vannini
Federico Parenti
Cristina Forghieri
Elisabetta Romagnoli
Daniela Massaro
Anna Zaghini
Gabriella Campadelli-Fiume
Tatiana Gianni
author_facet Andrea Vannini
Federico Parenti
Cristina Forghieri
Elisabetta Romagnoli
Daniela Massaro
Anna Zaghini
Gabriella Campadelli-Fiume
Tatiana Gianni
author_sort Andrea Vannini
collection DOAJ
description Background Cancer immunotherapy includes vaccines generated through distinct approaches, each with advantages and limitations. Those made of autologous or allogeneic whole cells do not require prior identification of antigens, that is, immunize against undetermined (agnostic) tumor antigens. However, they often exhibit low adjuvanticity and modest antigenicity. Viruses have emerged as elicitors and enhancers of immune responses. Oncolytic viruses are replicating anticancer agents, most often administered intratumorally. They derepress the immunosuppressive tumor microenvironment through different mechanisms, and some promote antitumor immunity—a strategy termed oncolytic immunotherapy. Tropism-retargeted oncolytic herpes simplex viruses (here ReHVs), generated in our laboratory, specifically target a tumor-associated antigen (TAA) of choice that serves as receptor for ReHV entry into the cancer cell. ReHVs do not cause off-target infections in preclinical models, are fully replication-competent and able to contrast the antiviral innate responses they elicit, and prime T cells against tumors.Methods We developed an ReHV-mediated immunotherapeutic platform (Re-IP) that consists of thymidine kinase-positive cancer cells ex vivo infected with ad hoc designed HER2-tropic ReHV implanted ectopically to immunize mice against cancer without direct tumor treatment.Results In a therapeutic-like setting, Re-IP robustly primed anticancer T cells that infiltrated distant untreated tumors and inhibited their growth. Tumor growth inhibition required CD8+ cells. Re-IP vaccinated against both the gnostic TAA (here HER2) employed for ReHV retargeting and a broader repertoire of agnostic tumor antigens, also sensitizing tumors to checkpoint blockade. Ectopically implanted uninfected cancer cells failed to elicit an immune response, highlighting the adjuvant effect of ReHV infection. Re-IP was effective in herpes simplex virus (HSV)-preimmune mice, unlike systemic treatments with oncolytic HSVs, which are blunted by prior antiviral immunity. Re-IP safety rested in the absence of replicating virus in off-target tissues and in tumors whose growth was inhibited.Conclusions Ectopically administered Re-IP adjuvants cancer cells’ immunogenicity without the need for direct tumor treatment. The induced T-cell immunity inhibits the growth of distant untreated tumors and remains effective in HSV-preimmune mice. In humans, this approach might be applied to elicit anticancer T-cell responses against hard-to-reach, unresectable, or metastatic lesions and to enhance immune cell activation and expansion in adoptive therapies.
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spelling doaj-art-9aba793f5a5c4d5e8557c98d71a7cea12025-08-20T03:32:19ZengBMJ Publishing GroupJournal for ImmunoTherapy of Cancer2051-14262025-07-0113710.1136/jitc-2025-011812Gnostic and agnostic immunotherapy by tropism-retargeted herpes simplex virus without direct tumor treatmentAndrea Vannini0Federico Parenti1Cristina Forghieri2Elisabetta Romagnoli3Daniela Massaro4Anna Zaghini5Gabriella Campadelli-Fiume6Tatiana Gianni7Department of Pharmacy and Biotechnology, University of Bologna, Bologna, ItalyDepartment of Medical and Surgical Sciences, University of Bologna, Bologna, ItalyDepartment of Medical and Surgical Sciences, University of Bologna, Bologna, ItalyDepartment of Medical and Surgical Sciences, University of Bologna, Bologna, ItalyDepartment of Veterinary Medical Sciences, University of Bologna, Bologna, ItalyDepartment of Veterinary Medical Sciences, University of Bologna, Bologna, ItalyDepartment of Medical and Surgical Sciences, University of Bologna, Bologna, ItalyDepartment of Medical and Surgical Sciences, University of Bologna, Bologna, ItalyBackground Cancer immunotherapy includes vaccines generated through distinct approaches, each with advantages and limitations. Those made of autologous or allogeneic whole cells do not require prior identification of antigens, that is, immunize against undetermined (agnostic) tumor antigens. However, they often exhibit low adjuvanticity and modest antigenicity. Viruses have emerged as elicitors and enhancers of immune responses. Oncolytic viruses are replicating anticancer agents, most often administered intratumorally. They derepress the immunosuppressive tumor microenvironment through different mechanisms, and some promote antitumor immunity—a strategy termed oncolytic immunotherapy. Tropism-retargeted oncolytic herpes simplex viruses (here ReHVs), generated in our laboratory, specifically target a tumor-associated antigen (TAA) of choice that serves as receptor for ReHV entry into the cancer cell. ReHVs do not cause off-target infections in preclinical models, are fully replication-competent and able to contrast the antiviral innate responses they elicit, and prime T cells against tumors.Methods We developed an ReHV-mediated immunotherapeutic platform (Re-IP) that consists of thymidine kinase-positive cancer cells ex vivo infected with ad hoc designed HER2-tropic ReHV implanted ectopically to immunize mice against cancer without direct tumor treatment.Results In a therapeutic-like setting, Re-IP robustly primed anticancer T cells that infiltrated distant untreated tumors and inhibited their growth. Tumor growth inhibition required CD8+ cells. Re-IP vaccinated against both the gnostic TAA (here HER2) employed for ReHV retargeting and a broader repertoire of agnostic tumor antigens, also sensitizing tumors to checkpoint blockade. Ectopically implanted uninfected cancer cells failed to elicit an immune response, highlighting the adjuvant effect of ReHV infection. Re-IP was effective in herpes simplex virus (HSV)-preimmune mice, unlike systemic treatments with oncolytic HSVs, which are blunted by prior antiviral immunity. Re-IP safety rested in the absence of replicating virus in off-target tissues and in tumors whose growth was inhibited.Conclusions Ectopically administered Re-IP adjuvants cancer cells’ immunogenicity without the need for direct tumor treatment. The induced T-cell immunity inhibits the growth of distant untreated tumors and remains effective in HSV-preimmune mice. In humans, this approach might be applied to elicit anticancer T-cell responses against hard-to-reach, unresectable, or metastatic lesions and to enhance immune cell activation and expansion in adoptive therapies.https://jitc.bmj.com/content/13/7/e011812.full
spellingShingle Andrea Vannini
Federico Parenti
Cristina Forghieri
Elisabetta Romagnoli
Daniela Massaro
Anna Zaghini
Gabriella Campadelli-Fiume
Tatiana Gianni
Gnostic and agnostic immunotherapy by tropism-retargeted herpes simplex virus without direct tumor treatment
Journal for ImmunoTherapy of Cancer
title Gnostic and agnostic immunotherapy by tropism-retargeted herpes simplex virus without direct tumor treatment
title_full Gnostic and agnostic immunotherapy by tropism-retargeted herpes simplex virus without direct tumor treatment
title_fullStr Gnostic and agnostic immunotherapy by tropism-retargeted herpes simplex virus without direct tumor treatment
title_full_unstemmed Gnostic and agnostic immunotherapy by tropism-retargeted herpes simplex virus without direct tumor treatment
title_short Gnostic and agnostic immunotherapy by tropism-retargeted herpes simplex virus without direct tumor treatment
title_sort gnostic and agnostic immunotherapy by tropism retargeted herpes simplex virus without direct tumor treatment
url https://jitc.bmj.com/content/13/7/e011812.full
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