Lyophilized, thermostable Spike or RBD immunogenic liposomes induce protective immunity against SARS-CoV-2 in mice.

Mabrouk, Moustafa T, Kevin Chiem, Edurne Rujas, Wei-Chiao Huang, Dushyant Jahagirdar, Breandan Quinn, Meera Surendran Nair, et al. 2021. “Lyophilized, Thermostable Spike or RBD Immunogenic Liposomes Induce Protective Immunity Against SARS-CoV-2 in Mice.”. Science Advances 7 (49): eabj1476.

Abstract

The COVID-19 pandemic has spurred interest in potent and thermostable SARS-CoV-2 vaccines. Here, we assess low-dose immunization with lyophilized nanoparticles decorated with recombinant SARS-CoV-2 antigens. The SARS-CoV-2 Spike glycoprotein or its receptor-binding domain (RBD; mouse vaccine dose, 0.1 μg) was displayed on liposomes incorporating a particle-inducing lipid, cobalt porphyrin-phospholipid (dose, 0.4 μg), along with monophosphoryl lipid A (dose, 0.16 μg) and QS-21 (dose, 0.16 μg). Following optimization of lyophilization conditions, Spike or RBD-decorated liposomes were effectively reconstituted and maintained conformational capacity for binding human angiotensin-converting enzyme 2 (hACE2) for at least a week when stored at 60°C in lyophilized but not liquid format. Prime-boost intramuscular vaccination of hACE2-transgenic mice with the reconstituted vaccine formulations induced effective antibody responses that inhibited RBD binding to hACE2 and neutralized pseudotyped and live SARS-CoV-2. Two days following viral challenge, immunized transgenic mice cleared the virus and were fully protected from lethal disease.

Last updated on 12/14/2023
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