Peritoneal metastases (PMs) occur due to the metastasis of gynecological and gastrointestinal cancers such as ovarian, colon, pancreatic, or gastric tumors. PM outgrowth is often fatal, and patients with PMs have a median survival of 6 months. Cowpea mosaic virus (CPMV) has been shown, when injected intratumorally, to act as an immunomodulator reversing the immunosuppressive tumor microenvironment, therefore turning cold tumors hot and priming systemic antitumor immunity. However, not all tumors are injectable, and PMs especially will require targeted treatments to direct CPMV toward the disseminated tumor nodules. Toward this goal, we designed and tested a CPMV nanoparticle targeted to S100A9, a key immune mediator for many cancer types indicated in cancer growth, invasiveness, and metastasis. Here, we chose to use an intraperitoneal (IP) colon cancer model, and analysis of IP gavage fluid demonstrates that S100A9 is upregulated following IP challenge. S100A9-targeted CPMV particles displaying peptide ligands specific for S100A9 homed to IP-disseminated tumors, and treatment led to improved survival and decreased tumor burden. Targeting CPMV to S100A9 improves preclinical outcomes and harbors the potential of utilizing CPMV for the treatment of IP-disseminated diseases.
The SARS-CoV-2 pandemic has highlighted the need for vaccines that are effective, but quickly produced. Of note, vaccines with plug-and-play capabilities that codeliver antigen and adjuvant to the same cell have shown remarkable success. Our approach of utilizing a nitrilotriacetic acid (NTA) histidine (His)-tag chemistry with viral adjuvants incorporates both of these characteristics: plug-and-play and co-delivery. We specifically utilize the cowpea mosaic virus (CPMV) and the virus-like particles from bacteriophage Qβ as adjuvants and bind the model antigen ovalbumin (OVA). Successful binding of the antigen to the adjuvant/carrier was verified by SDS-PAGE, western blot, and ELISA. Immunization in C57BL/6J mice demonstrates that with Qβ -but not CPMV -there is an improved antibody response against the target antigen using the Qβ-NiNTA:His-OVA versus a simple admixture of antigen and adjuvant. Antibody isotyping also shows that formulation of the vaccines can alter T helper biases; while the Qβ-NiNTA:His-OVA particle produces a balanced Th1/Th2 bias the admixture was strongly Th2. In a mouse model of B16F10-OVA, we further demonstrate improved survival and slower tumor growth in the vaccine groups compared to controls. The NiNTA:His chemistry demonstrates potential for rapid development of future generation vaccines enabling plug-and-play capabilities with effectiveness boosted by co-delivery to the same cell.
This study investigates the use of an immunotherapeutic plant virus, namely the cowpea mosaic virus (CPMV), that when used prophylactically and therapeutically can protect against metastatic cancer in multiple tumor mouse models. Metastatic cancer continues to be the main cause of death of most cancer patients, and new treatment modalities must be engineered to protect patients from metastatic disease. For instance, peritoneal metastases (PMs) are oftentimes fatal, and patients survive for a median 6 months following diagnosis. PMs are common for colon, ovarian, gastric, appendiceal, and pancreatic cancers. Previously, it was demonstrated that CPMV is a potent in situ vaccine causing tumor shrinkage with abscopal effect and long-term protection observed in tumor mouse models and canine cancer patients. CPMV functions as a toll like receptor (TLR) agonist and acts on innate immune cells to induce tumor cell killing and antigen processing to eventually prime adaptative and tumor-specific immunity. However, metastatic cancers such as PMs are not easily and directly injectable and therefore, we have expanded the ability of CPMV to protect against PMs by engineering targeted CPMV nanoparticles. Data indicates that CPMV can improve survival and slow tumor growth in a murine colon PM model compared to controls and that long-term survivors are further protected from re-challenge indicating tumor specificity. Analysis from current and past studies indicate that CPMV injection into the intraperitoneal space leads to distinct upregulation of immunostimulatory cytokines and recruitment of innate immune cell populations. PMs lead to extreme declines in quality of life of patients, and current treatments can be ineffective in slowing down or reducing tumor development and death - in tackling this problem, the data clearly points to the strong potential for CPMV-mediated therapeutics in the treatment and prophylaxis of PMs. Dr. Steinmetz is a co-founder of and has a financial interest in Mosaic ImmunoEngineering Inc. The other authors have no conflict of interest to declare. Acknowledgments: This work is supported in part through NIH grants R01 CA274640, R01 CA224605, R01 CA253615, CDMRP W81XWH2010742, and the Shaughnessy Family Fund for Nano-ImmunoEngineering (nanoIE at UC San Diego). Citation Format: Young Hun Chung, Britney A. Volckaert, Nicole F. Steinmetz. Treatment of metastatic cancers using immunotherapeutic cowpea mosaic virus nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 812.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.