High-throughput identification of prefusion-stabilizing mutations in SARS-CoV-2 spike

Designing prefusion-stabilized SARS-CoV-2 spike is critical for the effectiveness of COVID-19 vaccines. All COVID-19 vaccines in the US encode spike with K986P/V987P mutations to stabilize its prefusion conformation. However, contemporary methods on engineering prefusion-stabilized spike immunogens involve tedious experimental work and heavily rely on structural information. Here, we established a systematic and unbiased method of identifying mutations that concomitantly improve expression and stabilize the prefusion conformation of the SARS-CoV-2 spike. Our method integrated a fluorescence-based fusion assay, mammalian cell display technology, and deep mutational scanning. As a proof-of-concept, this method was applied to a region in the S2 domain that includes the first heptad repeat and central helix. Our results revealed that besides K986P and V987P, several mutations simultaneously improved expression and significantly lowered the fusogenicity of the spike. As prefusion stabilization is a common challenge for viral immunogen design, this work will help accelerate vaccine development against different viruses.

Clinical Study on Acupuncture at the Trigger Points on the Back for Cardioneurosis / 上海针灸杂志

Objective To observe the clinical efficacy of acupuncture at the trigger points on the back in treating cardioneurosis. Methods Fifty patients with cardioneurosis were selected to receive syndrome differentiation of traditional Chinese medicine, and then were evaluated for the improvement of symptoms respectively after first acupuncture treatment at the trigger points on the back and after 3~5 acupuncture treatments. Results Of the 50 cardioneurosis patients, 30 showed marked effect, 14 showed effective, 6 failed in the treatment, and the total effective rate was 88.0%. The total effective rate was 96.2%in patients of deficient heart yang, and was 75.0%in those of excessive fire due to yin deficiency, 83.3%in those of qi stagnation due to liver depression, and 83.3%in those of deficient heart yin. The improvement rate of subjective symptoms after 3~5 treatments was significantly different from that after the first treatment (P<0.05). Conclusions Acupuncture at the trigger points on the back is an effective approach in treating cardioneurosis, and it can achieve a marked efficacy with successive 3~5 sessions.