Breast Tumor-Associated Metalloproteases Restrict Reovirus Oncolysis by Cleaving the σ1 Cell Attachment Protein and Can Be Overcome by Mutation of σ1
Autor: | Patricia A. Chen, Sarah Haeflinger, Maya Shmulevitz, Jason P Fernandes, Mary M. Hitt, Isabelle Bernard, Heather E. Eaton, Francisca Cristi |
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Rok vydání: | 2019 |
Předmět: |
Proteases
viruses medicine.medical_treatment Immunology Virus Attachment Breast Neoplasms Biology Reoviridae Virus Replication Microbiology Cell Line Mice Viral Proteins 03 medical and health sciences 0302 clinical medicine Breast cancer Virology Tumor Microenvironment medicine Animals Humans 030304 developmental biology Oncolytic Virotherapy Infectivity 0303 health sciences Metalloproteinase Tumor microenvironment Protease virus diseases biochemical phenomena metabolism and nutrition medicine.disease N-Acetylneuraminic Acid Reoviridae Infections Virus-Cell Interactions 3. Good health Oncolytic virus A549 Cells 030220 oncology & carcinogenesis Insect Science Mutation Cancer cell Metalloproteases Cancer research Receptors Virus Capsid Proteins Female Cell Adhesion Molecules HeLa Cells |
Zdroj: | Journal of Virology. 93 |
ISSN: | 1098-5514 0022-538X |
Popis: | Reovirus is undergoing clinical testing as an oncolytic therapy for breast cancer. Given that reovirus naturally evolved to thrive in enteric environments, we sought to better understand how breast tumor microenvironments impinge on reovirus infection. Reovirus was treated with extracellular extracts generated from polyomavirus middle T-antigen-derived mouse breast tumors. Unexpectedly, these breast tumor extracellular extracts inactivated reovirus, reducing infectivity of reovirus particles by 100-fold. Mechanistically, inactivation was attributed to proteolytic cleavage of the viral cell attachment protein σ1, which diminished virus binding to sialic acid (SA)-low tumor cells. Among various specific protease class inhibitors and metal ions, EDTA and ZnCl(2) effectively modulated σ1 cleavage, indicating that breast tumor-associated zinc-dependent metalloproteases are responsible for reovirus inactivation. Moreover, media from MCF7, MB468, MD-MB-231, and HS578T breast cancer cell lines recapitulated σ1 cleavage and reovirus inactivation, suggesting that inactivation of reovirus is shared among mouse and human breast cancers and that breast cancer cells by themselves can be a source of reovirus-inactivating proteases. Binding assays and quantification of SA levels on a panel of cancer cells showed that truncated σ1 reduced virus binding to cells with low surface SA. To overcome this restriction, we generated a reovirus mutant with a mutation (T249I) in σ1 that prevents σ1 cleavage and inactivation by breast tumor-associated proteases. The mutant reovirus showed similar replication kinetics in tumorigenic cells, toxicity equivalent to that of wild-type reovirus in a severely compromised mouse model, and increased tumor titers. Overall, the data show that tumor microenvironments have the potential to reduce infectivity of reovirus. IMPORTANCE We demonstrate that metalloproteases in breast tumor microenvironments can inactivate reovirus. Our findings expose that tumor microenvironment proteases could have a negative impact on proteinaceous cancer therapies, such as reovirus, and that modification of such therapies to circumvent inactivation by tumor metalloproteases merits consideration. |
Databáze: | OpenAIRE |
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