Search

Lipid nanoparticle (LNP)-formulated nucleoside-modified mRNA vaccines have proven to be very successful in the fight against the coronavirus disease 2019 (COVID-19) pandemic. They are effective, safe, and can be produced in large quantities. However, the long-term storage of mRNA-LNP vaccines without freezing is still a challenge. Here, we demonstrate that nucleoside-modified mRNA-LNPs can be lyophilized, and the physicochemical properties of the lyophilized material do not significantly change for 12 weeks after storage at room temperature and for at least 24 weeks after storage at 4°C. Importantly, we show in comparative mouse studies that lyophilized firefly luciferase-encoding mRNA-LNPs maintain their high expression, and no decrease in the immunogenicity of a lyophilized influenza virus hemagglutinin-encoding mRNA-LNP vaccine was observed after 12 weeks of storage at room temperature or for at least 24 weeks after storage at 4°C. Our studies offer a potential solution to overcome the long-term storage-related limitations of nucleoside-modified mRNA-LNP vaccines., Competing Interests: Declaration of interests N.P. is named on a patent describing the use of nucleoside-modified mRNA in LNPs as a vaccine platform. He has disclosed those interests fully to the University of Pennsylvania, and he has in place an approved plan for managing any potential conflicts arising from licensing of that patent. K.K. is an employee of BioNTech., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Adjuvants are critical for improving the quality and magnitude of adaptive immune responses to vaccination. Lipid nanoparticle (LNP)-encapsulated nucleoside-modified mRNA vaccines have shown great efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the mechanism of action of this vaccine platform is not well-characterized. Using influenza virus and SARS-CoV-2 mRNA and protein subunit vaccines, we demonstrated that our LNP formulation has intrinsic adjuvant activity that promotes induction of strong T follicular helper cell, germinal center B cell, long-lived plasma cell, and memory B cell responses that are associated with durable and protective antibodies in mice. Comparative experiments demonstrated that this LNP formulation outperformed a widely used MF59-like adjuvant, AddaVax. The adjuvant activity of the LNP relies on the ionizable lipid component and on IL-6 cytokine induction but not on MyD88- or MAVS-dependent sensing of LNPs. Our study identified LNPs as a versatile adjuvant that enhances the efficacy of traditional and next-generation vaccine platforms., Competing Interests: Declaration of interests In accordance with the University of Pennsylvania policies and procedures and our ethical obligations as researchers, we report that D.W. and N.P. are named on a patent describing the use of nucleoside-modified mRNA in lipid nanoparticles as a vaccine platform. We have disclosed those interests fully to the University of Pennsylvania, and we have in place an approved plan for managing any potential conflicts arising from licensing of our patents. K.K. is an employee of BioNTech. P.J.C.L., B.L.M., and Y.K.T. are employees of Acuitas Therapeutics, a company involved in the development of mRNA-LNP therapeutics. Y.K.T., D.W., and M.G.A. are named on patents that describe lipid nanoparticles for delivery of nucleic acid therapeutics, including mRNA and the use of modified mRNA in lipid nanoparticles as a vaccine platform. The Icahn School of Medicine at Mount Sinai has filed patent applications regarding SARS-CoV-2 and influenza virus vaccines that name F.K. as co-inventor., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Nucleoside-modified messenger RNA (mRNA)-lipid nanoparticles (LNPs) are the basis for the first two EUA (Emergency Use Authorization) COVID-19 vaccines. The use of nucleoside-modified mRNA as a pharmacological agent opens immense opportunities for therapeutic, prophylactic and diagnostic molecular interventions. In particular, mRNA-based drugs may specifically modulate immune cells, such as T lymphocytes, for immunotherapy of oncologic, infectious and other conditions. The key challenge, however, is that T cells are notoriously resistant to transfection by exogenous mRNA. Here, we report that conjugating CD4 antibody to LNPs enables specific targeting and mRNA interventions to CD4+ cells, including T cells. After systemic injection in mice, CD4-targeted radiolabeled mRNA-LNPs accumulated in spleen, providing ∼30-fold higher signal of reporter mRNA in T cells isolated from spleen as compared with non-targeted mRNA-LNPs. Intravenous injection of CD4-targeted LNPs loaded with Cre recombinase-encoding mRNA provided specific dose-dependent loxP-mediated genetic recombination, resulting in reporter gene expression in about 60% and 40% of CD4+ T cells in spleen and lymph nodes, respectively. T cell phenotyping showed uniform transfection of T cell subpopulations, with no variability in uptake of CD4-targeted mRNA-LNPs in naive, central memory, and effector cells. The specific and efficient targeting and transfection of mRNA to T cells established in this study provides a platform technology for immunotherapy of devastating conditions and HIV cure., Competing Interests: Declaration of interests H.P., I.T., N.P., V.R.M., and D.W. are inventors on a patent filed on some aspects of this work. Those interests have been fully disclosed to the University of Pennsylvania. All other authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

SARS-CoV-2 infection has emerged as a serious global pandemic. Because of the high transmissibility of the virus and the high rate of morbidity and mortality associated with COVID-19, developing effective and safe vaccines is a top research priority. Here, we provide a detailed evaluation of the immunogenicity of lipid nanoparticle-encapsulated, nucleoside-modified mRNA (mRNA-LNP) vaccines encoding the full-length SARS-CoV-2 spike protein or the spike receptor binding domain in mice. We demonstrate that a single dose of these vaccines induces strong type 1 CD4 + and CD8 + T cell responses, as well as long-lived plasma and memory B cell responses. Additionally, we detect robust and sustained neutralizing antibody responses and the antibodies elicited by nucleoside-modified mRNA vaccines do not show antibody-dependent enhancement of infection in vitro. Our findings suggest that the nucleoside-modified mRNA-LNP vaccine platform can induce robust immune responses and is a promising candidate to combat COVID-19., Competing Interests: Declaration of Interests In accordance with the University of Pennsylvania policies and procedures and our ethical obligations as researchers, we report that D.W. and K.K. are named on patents that describe the use of nucleoside-modified mRNA as a platform to deliver therapeutic proteins. D.W. and N.P. are also named on a patent describing the use of nucleoside-modified mRNA in lipid nanoparticles as a vaccine platform. We have disclosed those interests fully to the University of Pennsylvania, and we have an approved plan for managing any potential conflicts arising from licensing of our patents in place. K.K. is an employee of BioNTech. P.J.C.L. and Y.K.T. are employees of Acuitas Therapeutics, a company involved in the development of mRNA-LNP therapeutics. Y.K.T. is named on patents that describe lipid nanoparticles for delivery of nucleic acid therapeutics including mRNA and the use of modified mRNA in lipid nanoparticles as a vaccine platform., (Published by Elsevier Inc.)