Valdivia Lara, Edgar GuillermoAlonso Miguel, DanielPérez Alenza, María De Los DoloresZimmermann, Anna Barbara EmiliaSchaafsma, EvelienKolling IV, Fred W.Barreno San Antolín, LucíaAlonso Díez, ÁngelaBeiss, VeroniqueAffonso de Oliveira, Jessica FernandaSuárez Redondo, MaríaFiering, StevenSteinmetz, Nicole F.Vom Berg, JohannesPeña Fernández, Laura LuisaArias Pulido, Hugo2024-05-242024-05-242023-09-08Valdivia, G.; AlonsoMiguel, D.; Perez-Alenza, M.D.; Zimmermann, A.B.E.; Schaafsma, E.; Kolling, F.W., IV; Barreno, L.; Alonso-Diez, A.; Beiss, V.; Affonso de Oliveira, J.F.; et al. Neoadjuvant Intratumoral Immunotherapy with Cowpea Mosaic Virus Induces Local and Systemic Antitumor Efficacy in Canine Mammary Cancer Patients. Cells 2023, 12, 2241. https://doi.org/ 10.3390/cells1218224110.3390/cells12182241https://hdl.handle.net/20.500.14352/1044302023 Descuento MDPIThe lack of optimal models to evaluate novel agents is delaying the development of effective immunotherapies against human breast cancer (BC). In this prospective open label study, we applied neoadjuvant intratumoral immunotherapy with empty cowpea mosaic virus-like particles (eCPMV) to 11 companion dogs diagnosed with canine mammary cancer (CMC), a spontaneous tumor resembling human BC. We found that two neoadjuvant intratumoral eCPMV injections resulted in tumor reduction in injected tumors in all patients and in noninjected tumors located in the ipsilateral and contralateral mammary chains of injected dogs. Tumor reduction was independent of clinical stage, tumor size, histopathologic grade, and tumor molecular subtype. RNA-seq-based analysis of injected tumors indicated a decrease in DNA replication activity and an increase in activated dendritic cell infiltration in the tumor microenvironment. Immunohistochemistry analysis demonstrated significant intratumoral increases in neutrophils, T and B lymphocytes, and plasma cells. eCPMV intratumoral immunotherapy demonstrated antitumor efficacy without any adverse effects. This novel immunotherapy has the potential for improving outcomes for human BC patients.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article2073-4409https://doi.org/10.3390/cells12182241https://pubmed.ncbi.nlm.nih.gov/37759464/open access636.7.09:616-006Canine mammary cancerIntratumoral immunotherapyPlant virusCowpea mosaic virusNanoparticlesImmune cellsTumor microenvironmentPatient outcomeVeterinaria3109 Ciencias Veterinarias