Key mutations in the spike protein of SARS-CoV-2 affecting neutralization resistance and viral internalization.

To control the ongoing COVID-19 pandemic, a variety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been developed. However, the rapid mutations of SARS-CoV-2 spike (S) protein may reduce the protective efficacy of the existing vaccines which is mainly determined by the level of neutralizing antibodies targeting S. In this study, we screened prevalent S mutations and constructed 124 pseudotyped lentiviral particles carrying these mutants. We challenged these pseudoviruses with sera vaccinated by Sinovac CoronaVac and ZF2001 vaccines, two popular vaccines designed for the initial strain of SARS-CoV-2, and then systematically assessed the susceptivity of these SARS-CoV-2 variants to the immune sera of vaccines. As a result, 14 S mutants (H146Y, V320I + S477N, V382L, K444R, L455F + S477N, L452M + F486L, F486L, Y508H, P521R, A626S, S477N + S698L, A701V, S477N + T778I, E1144Q) were found to be significantly resistant to neutralization, indicating reduced protective efficacy of the vaccines against these SARS-CoV-2 variants. In addition, F486L and Y508H significantly enhanced the utilization of human angiotensin-converting enzyme 2, suggesting a potentially elevated infectivity of these two mutants. In conclusion, our results show that some prevalent S mutations of SARS-CoV-2 reduced the protective efficacy of current vaccines and enhance the infectivity of the virus, indicating the necessity of vaccine renewal and providing direction for the development of new vaccines.

APOA4 as a novel predictor of prognosis in Stevens-Johnson syndrome/toxic epidermal necrolysis: A proteomics analysis from two prospective cohorts.

BACKGROUND: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but life-threatening adverse drug reactions. Conventional systemic therapies are of limited efficacy and often exhibit strong side effects. OBJECTIVE: To assess the efficacy and safety of the combination treatment with a tumor necrosis factor-α antagonist adalimumab and delineate the underlying mechanisms. METHODS: We evaluated the efficacy and safety of the combination therapy with adalimumab by comparing 2 treatment cohorts of SJS/TEN patients. Patient plasma samples were collected for proteomics analysis. RESULTS: The combination therapy with adalimumab significantly shortened the time to mucocutaneous re-epithelization and healing, with reduced side effects caused by corticosteroids. Plasma proteomic profiling showed that apolipoprotein A-IV (APOA4) was one of the most significant differentially expressed proteins. Multivariate regression analysis revealed that APOA4 level was significantly associated with prognosis parameter of SJS/TEN (P = .004), but not with disease severity score (severity-of-illness score for toxic epidermal necrolysis [SCORTEN]) (P = .118). Thus further research will be helpful to effectively incorporate APOA4 into current SCORTEN-driven protocols. LIMITATIONS: The cohort size is relatively small. Both cohorts had low overall SCORTEN scores. CONCLUSION: Adalimumab in combination with corticosteroids demonstrates significant clinical benefits over corticosteroids alone in SJS/TEN patients. Moreover, APOA4 may serve as a novel prognostic marker of SJS/TEN.