Lyophilized, thermostable Spike or RBD immunogenic liposomes induce protective immunity against SARS-CoV-2 in mice.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34851667.
- Also identified by DOI 10.1126/sciadv.abj1476 and PMC identifier 8635435.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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.