A cowpea mosaic virus adjuvant conjugated to liposomes loaded with tumor cell lysates as an ovarian cancer vaccine

Current treatment options for ovarian cancer are limited to surgery to remove tumor tissues and chemotherapy. Although such treatments could provide a short period of remission, most patients still experience recurrent metastatic diseases. Here we present a nanotechnology-based personalized cancer vaccine that can be administrated to patients during the remission stage to prevent recurrent diseases. Autologous tumor cell lysates (TCL) are intriguing, personalized antigens that could be extracted from surgically recovered tumor tissues from patients containing all neoantigens. As proof of concept, we use TCL isolated from a murine ovarian cancer cell line. TCL are first encapsulated in liposomes (TCL-Lip), which are then attached to cowpea mosaic virus (CPMV), a plant virus as a potent adjuvant. Using the ID8-Defb29/Vegf-a-Luc tumor model in female mice, the TCL-Lip-CPMV conjugate vaccine protects mice from tumor challenge by improving antigen processing and presentation, priming an adaptive anti-tumor immunity. Using ovalbumin (OVA) as a model antigen, OVA-Lip-CPMV vaccination protects mice from lung metastasis post-surgical removal of the primary B16F10-OVA dermal tumors. This research establishes a platform by combining two nanoparticle technologies into a single formulation for the simultaneous delivery of antigens and adjuvants, advancing the development of cancer vaccines and immunotherapies.