There is an urgent need for vaccines against coronavirus disease 2019 (COVID-19) because of the ongoing SARS-CoV-2 pandemic. Among all approaches, a messenger RNA (mRNA)-based vaccine has emerged as a rapid and versatile platform to quickly respond to this challenge. Here, we developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor binding domain (RBD) of SARS-CoV-2 as a vaccine candidate (called ARCoV). Intramuscular immunization of ARCoV mRNA-LNP elicited robust neutralizing antibodies against SARS-CoV-2 as well as a Th1-biased cellular response in mice and non-human primates. Two doses of ARCoV immunization in mice conferred complete protection against the challenge of a SARS-CoV-2 mouse-adapted strain. Additionally, ARCoV is manufactured as a liquid formulation and can be stored at room temperature for at least 1 week. ARCoV is currently being evaluated in phase 1 clinical trials.

Pyroptosis is a type of programmed cell death, which has been associated with multiple inflammatory diseases including diabetic atherosclerosis (DA). This study aims to explore the role of sinapic acid (SA) in the pyroptosis of macrophages in DA. Our results from the in vivo experiments showed that low-dose (≤50 mg/kg) chronic SA administration suppressed serum endothelin 1 (ET-1) and interleukin-1β (IL-1β) contents, pyroptotic death of bone marrow-derived macrophages, and the expression of pyroptotic proteins ASC, NRLP3, and caspase-1. Besides, lncRNA-metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was robustly upregulated in the macrophages of rats with DA and could be lowered by low-dose SA administration. Gene overexpression and knockdown experiments showed that MALAT1 had a modestly positive effect on the pyroptosis of normal macrophages. Moreover, in macrophages incubated with high-glucose and Ox-LDL, 1-μM SA treatment displayed a suppressive effect on the cell pyroptosis similar to that of MALAT1 knockdown. Transfection of the pcDNA-MALAT1 expression vector counteracted the decrease in MALAT1 expression and macrophage pyroptosis caused by SA. In conclusion, low-dose SA can abate the pyroptosis of macrophages by downregulation of lncRNA-MALAT1 in rats with DA.

In this study, a label-free, low-cost, and fast ferrohydrodynamic cell separation scheme is demonstrated using HeLa cells (an epithelial cell line) and red blood cells. The separation is based on cell size difference, and conducted in a custom-made biocompatible ferrofluid that retains the viability of cells during and after the assay for downstream analysis. The scheme offers moderate-throughput (≈106 cells h−1 for a single channel device) and extremely high recovery rate (>99%) without the use of any label. It is envisioned that this separation scheme will have clinical applications in settings where rapid cell enrichment and removal of contaminating blood will improve efficiency of screening and diagnosis such as cervical cancer screening based on mixed populations in exfoliated samples.