RESUMO
Functional tumor-specific cytotoxic T cells elicited by therapeutic cancer vaccination in combination with oncolytic viruses offer opportunities to address resistance to checkpoint blockade therapy. Two cancer vaccines, the self-adjuvanting protein vaccine KISIMA, and the recombinant oncolytic vesicular stomatitis virus pseudotyped with LCMV-GP expressing tumor-associated antigens, termed VSV-GP-TAA, both show promise as a single agent. Here we find that, when given in a heterologous prime-boost regimen with an optimized schedule and route of administration, combining KISIMA and VSV-GP-TAA vaccinations induces better cancer immunity than individually. Using several mouse tumor models with varying degrees of susceptibility for viral replication, we find that priming with KISIMA-TAA followed by VSV-GP-TAA boost causes profound changes in the tumor microenvironment, and induces a large pool of poly-functional and persistent antigen-specific cytotoxic T cells in the periphery. Combining this heterologous vaccination with checkpoint blockade further improves therapeutic efficacy with long-term survival in the spectrum. Overall, heterologous vaccination with KISIMA and VSV-GP-TAA could sensitize non-inflamed tumors to checkpoint blockade therapy.
Assuntos
Vacinas Anticâncer/imunologia , Neoplasias/imunologia , Neoplasias/terapia , Vírus Oncolíticos/imunologia , Vírus da Estomatite Vesicular Indiana/imunologia , Animais , Antígenos de Neoplasias/administração & dosagem , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/administração & dosagem , Terapia Combinada , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Terapia Viral Oncolítica , Vírus Oncolíticos/genética , Vírus Oncolíticos/fisiologia , Linfócitos T Citotóxicos/imunologia , Microambiente Tumoral , Vacinação , Vírus da Estomatite Vesicular Indiana/genética , Vírus da Estomatite Vesicular Indiana/fisiologia , Replicação ViralRESUMO
Nasopharyngeal cancer (NPC), endemic in Southeast Asia, lacks effective diagnostic and therapeutic strategies. Even in high-income countries the 5-year survival rate for stage IV NPC is less than 40%. Here we report high somatostatin receptor 2 (SSTR2) expression in multiple clinical cohorts comprising 402 primary, locally recurrent and metastatic NPCs. We show that SSTR2 expression is induced by the Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) via the NF-κB pathway. Using cell-based and preclinical rodent models, we demonstrate the therapeutic potential of SSTR2 targeting using a cytotoxic drug conjugate, PEN-221, which is found to be superior to FDA-approved SSTR2-binding cytostatic agents. Furthermore, we reveal significant correlation of SSTR expression with increased rates of survival and report in vivo uptake of the SSTR2-binding 68Ga-DOTA-peptide radioconjugate in PET-CT scanning in a clinical trial of NPC patients (NCT03670342). These findings reveal a key role in EBV-associated NPC for SSTR2 in infection, imaging, targeted therapy and survival.
Assuntos
Infecções por Vírus Epstein-Barr , Regulação Neoplásica da Expressão Gênica , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Recidiva Local de Neoplasia , Receptores de Somatostatina , Proteínas da Matriz Viral , Animais , Feminino , Humanos , Masculino , Camundongos , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/mortalidade , Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/efeitos dos fármacos , Herpesvirus Humano 4/crescimento & desenvolvimento , Herpesvirus Humano 4/patogenicidade , Interações Hospedeiro-Patógeno/genética , Metástase Linfática , Camundongos Nus , Terapia de Alvo Molecular , Carcinoma Nasofaríngeo/tratamento farmacológico , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/mortalidade , Carcinoma Nasofaríngeo/virologia , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/virologia , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/virologia , NF-kappa B/genética , NF-kappa B/metabolismo , Octreotida/farmacologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Receptores de Somatostatina/antagonistas & inibidores , Receptores de Somatostatina/genética , Receptores de Somatostatina/metabolismo , Transdução de Sinais , Análise de Sobrevida , Proteínas da Matriz Viral/antagonistas & inibidores , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
In vivo studies are the mainstay of translational immune-oncology and virotherapy research. In general oncology, bioluminescence imaging provides a convenient and reliable tool to visualize disseminated tumors and monitor growth kinetics or treatment effects. Unique aspects of this method in the field of oncolytic viruses are tracing the process of tumor-specific targeting, assessing potential off-target replication, and visualizing intratumoral spread. In addition, the longitudinal monitoring of virus activity kinetics over time is a very powerful feature supporting the subsequent, often elaborate, preclinical biodistribution and pharmtox program. Here we present a step-by-step standard imaging protocol used in our group for both tumor and virus monitoring, along with background information and general principles that should allow the reader to modify and adapt the protocol according to their needs.
Assuntos
Terapia Genética , Vetores Genéticos/genética , Imagem Molecular , Terapia Viral Oncolítica , Vírus Oncolíticos/genética , Animais , Análise de Dados , Modelos Animais de Doenças , Expressão Gênica , Genes Reporter , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Humanos , Processamento de Imagem Assistida por Computador , Medições Luminescentes , Camundongos , Imagem Molecular/métodos , Neoplasias/diagnóstico , Neoplasias/terapia , Terapia Viral Oncolítica/métodos , Software , Distribuição Tecidual , Transgenes , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Oncolytic virotherapy is thought to result in direct virus-induced lytic tumour killing and simultaneous activation of innate and tumour-specific adaptive immune responses. Using a chimeric vesicular stomatitis virus variant VSV-GP, we addressed the direct oncolytic effects and the role of anti-tumour immune induction in the syngeneic mouse lung cancer model LLC1. METHODS: To study a tumour system with limited antiviral effects, we generated interferon receptor-deficient cells (LLC1-IFNAR1-/-). Therapeutic efficacy of VSV-GP was assessed in vivo in syngeneic C57BL/6 and athymic nude mice bearing subcutaneous tumours. VSV-GP treatment effects were analysed using bioluminescent imaging (BLI), immunohistochemistry, ELISpot, flow cytometry, multiplex ELISA and Nanostring® assays. RESULTS: Interferon insensitivity correlated with VSV-GP replication and therapeutic outcome. BLI revealed tumour-to-tumour spread of viral progeny in bilateral tumours. Histological and gene expression analysis confirmed widespread and rapid infection and cell killing within the tumour with activation of innate and adaptive immune-response markers. However, treatment outcome was increased in the absence of CD8+ T cells and surviving mice showed little protection from tumour re-challenge, indicating limited therapeutic contribution by the activated immune system. CONCLUSION: These studies present a case for a predominantly lytic treatment effect of VSV-GP in a syngeneic mouse lung cancer model.
