From Event: 17th International Photodynamic Association World Congress, 2019
Even though a patient has a good immune system, tumors are shielded from it, because tumors grow by suppressing the host’s immune-response by various mechanisms. They are keeping their local microenvironment immune suppressed by producing immune suppressive cytokines like IL-10 and TGF-b, express immune checkpoint ligands like Programmed Death Ligand 1 (PDL1), and harbor immune suppressive cells like Tregs and MDSCs. To overcome these barriers a stronger anti-tumour immune-response is essential. We evaluated a whole cell vaccine with extracorporeal Rutherrin®-PDT treated cancer cells (RuVaCareTM) to break the suppressive barrier in the RG2-glioblastoma model. Rutherrin®-PDT induced strong immunogenic cell death (ICD) in glioblastoma cells in-vitro. RuVaCareTM supernatants showed significantly higher level of extracellular ATP, which is known to induce recruitment of antigen presenting cells (APCs) and their activation by eliciting an effective anti-tumour immune-response. Extracellular calreticulin (CRT) is one of the hallmarks of ICD; its expression went up in more than 85% cells undergoing Rutherrin®-PDT mediated cell death. There was a close to 10 times increase in expression of HSP 70 in RuVaCareTM. Immunostimulatory cytokines IFNa, IL-1b and GMCSF expression is high in the RuVaCareTM. In-vivo efficacy of the RuVaCare™ was evaluated in orthotopic RG2 rat glioblastoma model. There was a significant increase (~43% with 2-time vaccine and 87% in the 6-time vaccine) in survival in the RuVaCare™ vaccinated groups compared to unvaccinated controls. Increased intratumoral CD8+T-cell numbers are shown to be correlated with increased survival in glioblastoma rats, with RuVaCare™ there was a significant increase in the number of CD8+T-cells.
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Lothar D. Lilge, Manjunatha Ankathatti Munegowda, Arkady Mandel, and Roger Dumoulin-White, "A new platform technology RuVaCare, an extracorporeal anti-cancer vaccine is efficient in breaking immune barrier to target cancer cells (Conference Presentation)," Proc. SPIE 11070, 17th International Photodynamic Association World Congress, 110703R (Presented at 17th International Photodynamic Association World Congress: July 02, 2019; Published: 14 August 2019); https://doi.org/10.1117/12.2526627.6069257781001.