Abstract 714: From cancer to COVID-19- development of a dendritic cell-targeted nano-vaccine for prevention and therapy of COVID-19

Abstract

Dendritic cells (DC) are antigen-presenting cells with an important role in the initiation and regulation of the innate and adaptive arms of the immune system. By efficient presentation of antigens, DC elicit an antigen-specific immune response. Therefore, we previously established in our laboratory a melanoma-DC-targeted NP that was evaluated and validated against aggressive melanoma. Although DC-therapy is mainly exploited in the treatment of cancer, DC are becoming a key therapeutic target in other pathologies such as infectious diseases. Viral pathogens, similarly, to cancer, modulate the host defense mechanisms to their benefit. COVID-19, an ongoing pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally and is already infecting tens of millions of people worldwide. Historically, vaccines are among therapies with the greatest impact in health and constitute an unmet medical need against coronavirus disease-19 (COVID-19) pandemic. To that end, we repurposed our recently published melanoma-targeted NP to co-deliver modulators of host immune response and SARS-CoV-2 specific antigen epitopes discovered by a computational approach integrating 3D information with large-scale statistical analysis. The immune response kinetics in patients infected with SARS-CoV-2 is poorly understood, but recent reports show that germinal B cells and active follicular T-helper cells, IgM/IgG SARS-CoV-2 antibodies, in addition to an enhanced cellular immunity, are found in patients with mild-to-moderate SARS-CoV-2 infection. Our preliminary data demonstrated that our nano-vaccine was able to activate specific immune cell response of effector T cells and B cells and decrease the regulatory activity of T cells, compared to controls. Moreover, we found that our DC-targeted SARS-CoV-2 NP successfully induced antigen-specific secretion of IgM and IgG antibodies with high binding affinity to the antigens. Importantly, our nano-vaccine elicited specific neutralization of Spike virus like particles (VLPs) by sera of immunized mice. We hypothesize that implementing our novel nano-vaccine platform for COVID-19 will lead to a safe and efficacious COVID-19 vaccine ready for first-in-human clinical trials. Citation Format: Daniella Vaskovich-Koubi, Ron Kleiner, Yulia Liubomirski, Eilam Yeini, Galia Tiram, Sabina Pozzi, Anat Eldar-Boock, Helena F. Florindo, Ronit Satchi-Fainaro. From cancer to COVID-19- development of a dendritic cell-targeted nano-vaccine for prevention and therapy of COVID-19 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 714.