Long-term passaging of replication competent pseudo-typed SARS-CoV-2 reveals the antiviral breadth of monoclonal and bispecific antibody cocktails

The continuous emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants poses challenges to the effectiveness of neutralizing antibodies. Rational design of antibody cocktails is a realizable approach addressing viral immune evasion. However, evaluating the breadth of antibody cocktails is essential for understanding the development potential. Here, based on a replication competent vesicular stomatitis virus model that incorporates the spike of SARS-CoV-2 (VSV-SARS-CoV-2), we evaluated the breadth of a number of antibody cocktails consisting of monoclonal antibodies and bispecific antibodies by long-term passaging the virus in the presence of the cocktails. Results from over two-month passaging of the virus showed that 9E12+10D4+2G1 and 7B9-9D11+2G1 from these cocktails were highly resistant to random mutation, and there was no breakthrough after 30 rounds of passaging. As a control, antibody REGN10933 was broken through in the third passage. Next generation sequencing was performed and several critical mutations related to viral evasion were identified. These mutations caused a decrease in neutralization efficiency, but the reduced replication rate and ACE2 susceptibility of the mutant virus suggested that they might not have the potential to become epidemic strains. The 9E12+10D4+2G1 and 7B9-9D11+2G1 cocktails that picked from the VSV-SARS-CoV-2 system efficiently neutralized all current variants of concern and variants of interest including the most recent variants Delta and Omicron, as well as SARS-CoV-1. Our results highlight the feasibility of using the VSV-SARS-CoV-2 system to develop SARS-CoV-2 antibody cocktails and provide a reference for the clinical selection of therapeutic strategies to address the mutational escape of SARS-CoV-2.

Efficient Neutralization of SARS-CoV-2 Omicron and Other VOCs by a Broad Spectrum Antibody 8G3

Numerous mutations in the spike protein of SARS-CoV-2 B.1.1.529 Omicron variant pose a crisis for antibody-based immunotherapies. The efficacy of emergency use authorized (EUA) antibodies that developed in early SARS-CoV-2 pandemic seems to be in flounder. We tested the Omicron neutralization efficacy of an early B cell antibody repertoire as well as several EUA antibodies in pseudovirus and authentic virus systems. More than half of the antibodies in the repertoire that showed good activity against WA1/2020 previously had completely lost neutralizing activity against Omicron, while antibody 8G3 displayed non-regressive activity. EUA antibodies Etesevimab, Casirivimab, Imdevimab and Bamlanivimab were entirely desensitized by Omicron. Only Sotrovimab targeting the non-ACE2 overlap epitope showed a dramatic decrease activity. Antibody 8G3 efficiently neutralized Omicron in pseudovirus and authentic virus systems. The in vivo results showed that Omicron virus was less virulent than the WA1/2020 strain, but still caused deterioration of health and even death in mice. Treatment with 8G3 quickly cleared virus load of mice. Antibody 8G3 also showed excellent activity against other variants of concern (VOCs), especially more efficient against authentic Delta plus virus. Collectively, our results suggest that neutralizing antibodies with breadth remains broad neutralizing activity in tackling SARS-CoV-2 infection despite the universal evasion from EUA antibodies by Omicron variant.

Comprehensive Evaluation of ACE2-Fc Combination with Neutralization Antibody on Broad Protection against SARS-CoV-2 and Its Variants

Emerging SARS-CoV-2 variants are threatening the efficacy of antibody therapies. Combination treatments including ACE2-Fc have been developed to overcome the evasion of neutralizing antibodies (NAbs) in individual cases. Here we conducted a comprehensive evaluation of this strategy by combining ACE2-Fc with NAbs of diverse epitopes on the RBD. NAb+ACE2-Fc combinations efficiently neutralized HIV-based pseudovirus carrying the spike protein of the Delta or Omicron variants, achieving a balance between efficacy and breadth. In an antibody escape assay using replication-competent VSV-SARS-CoV-2-S, all the combinations had no escape after fifteen passages. By comparison, all the NAbs without combo with ACE2-Fc had escaped within six passages. Further, the VSV-S variants escaped from NAbs were neutralized by ACE2-Fc, revealing the mechanism of NAb+ACE2-Fc combinations survived after fifteen passages. We finally examined ACE2-Fc neutralization against pseudovirus variants that were resistant to the therapeutic antibodies currently in clinic. Our results suggest ACE2-Fc is a universal combination partner to combat SARS-CoV-2 variants including Delta and Omicron.

Broad ultra-potent neutralization of SARS-CoV-2 variants by monoclonal antibodies specific to the tip of RBD

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) continue to wreak havoc across the globe. Higher transmissibility and immunologic resistance of VOCs bring unprecedented challenges to epidemic extinguishment. Here we describe a monoclonal antibody, 2G1, that neutralizes all current VOCs and has surprising tolerance to mutations adjacent to or within its interaction epitope. Cryo-electron microscopy structure showed that 2G1 bound to the tip of receptor binding domain (RBD) of spike protein with small contact interface but strong hydrophobic effect, which resulted in nanomolar to sub-nanomolar affinities to spike proteins. The epitope of 2G1 on RBD partially overlaps with ACE2 interface, which gives 2G1 ability to block interaction between RBD and ACE2. The narrow binding epitope but high affinity bestow outstanding therapeutic efficacy upon 2G1 that neutralized VOCs with sub-nanomolar IC50 in vitro. In SARS-CoV-2 and Beta- and Delta-variant-challenged transgenic mice and rhesus macaque models, 2G1 protected animals from clinical illness and eliminated viral burden, without serious impact to animal safety. Mutagenesis experiments suggest that 2G1 could be potentially capable of dealing with emerging SARS-CoV-2 variants in future. This report characterized the therapeutic antibodies specific to the tip of spike against SARS-CoV-2 variants and highlights the potential clinical applications as well as for developing vaccine and cocktail therapy.

Correlation of serum complement C1q level with metabolic syndrome / 中华检验医学杂志

Objectives To analyze the changes of serum complement C1q level in patients with metabolic syndrome (MS) and investigate whether it is associated with lipid metabolism and glycometabolism. Methods In a cross-sectional study, the subjects were selected as the patients and healthy people who went to the second xiangya hospital of central south university from July 2017 to June 2018. A total of 152 MS patients were enrolled and another 90 healthy subjects were enrolled as control group. Anthropometry parameters such as body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP) were measured. Serum concentrations of C1q and other biochemical indexes including blood glucose (GLU), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured in all groups. The correlations between C1q and these parameters were analyzed by spearman's rho test and the clinical value of C1q in predicting MS was further evaluated by stepwise multiple linear regression analysis. Results MS group had higher serum C1q levels (244.34±62.66) mg/L compared with the control group (202.37±35.92) mg/L (t=-6.250, P=0.000). C1q levels (244.34±62.66) mg/L were positively associated with TG levels [2.34(1.89, 3.62)] mmol/L (r=0.245, P=0.001), TC levels (4.91±1.26) mmol/L (r=0.398, P=0.000), LDL-C levels (3.23±1.03) mmol/L (r=0.325, P=0.000) in MS group, While C1q levels (258.92±69.59)mg/L were positively associated with SBP (144.76 ± 22.94) mmHg (r=0.388, P=0.018), TG levels [2.65(1.87, 3.82)] mmol / L (r=0.482, P=0.003), TC levels (5.18±1.31) mmol/L (r=0.529,P=0.001) in MS patients with obesity. The stepwise multiple regression analysis showed that TG levels were independently correlated with serum C1q levels both in MS patients (β=0.302, P=0.000) and in MS patients with obesity (β=0.653, P=0.000) after adjusting for age, gender and other biochemical markers. Conclusions MS patients had higher C1q levels than healthy subjects and serum C1q levels were closely positive related to harmful lipid profiles. Serum TG level was an independent influencing factor of serum C1q in MS patients.

A retrospective analysis of infection and antimicrobial susceptibility of genital mycoplasma in Changsha from 2010 to 2017 / 中华检验医学杂志

Objective@#To study the prevalence and antimicrobial susceptibility of Ureaplasma urealyticum (Uu) and Mycoplasma hominis (Mh) in Changsha, and provide laboratory evidence for clinical drug use.@*Methods@#A retrospective study was conducted to analyze 53 006 specimens of suspected genital mycoplasma infection in Xiangya Second Hospital of Changsha District and Hunan Wangwang Hospital from 2010 to 2017, and to analyze the infection rate and drug resistance rate of Uu and Mh.@*Results@#From 2010 to 2017, a total of 53 006 specimens were detected, where there were 16 830 cases of Uu infection, the infection rate was 31.75%; 2 471 cases of Mh infection, the infection rate was 4.66%; and 1 071 cases of Uu and Mh mixed infection, the infection rate was 2.02%. Male Uu infection rate was 19.48%(5 989/30 749), which was lower than the female infection rate 48.71%(10 841/22 257) (χ2=5 091, P<0.001); male Mh infection rate was 3.16%(973/30 749), lower than female infection rate 6.73%(1 498/22 257) (χ2=369,P<0.001). The population of genital mycoplasma infection is concentrated between 20 and 40 years old, accounting for 71.76% (12 077/16 830). The drug resistance rates of Uu and Mh to doxycycline and minocycline were less than 2%, while the drug resistance rate to quinolones was higher; The resistance rate of Uu to macrolide antibiotics such as erythromycin, josamycin and clarithromycin were less than 2%, while the resistance rate to azithromycin, erythromycin and roxithromycin were higher, 29.74%(5 006/16 830) and 53.74%(9 045/16 830), respectively, and the resistance rate of Mh to macrolide antibiotics (except josamycin) was higher than 90%.Between 2010 and 2017, a gradually increasing resistance of ureaplasmas to azithromycin, from 3.81% (46/1 206) in 2010 to 53.15% (1 503/2 828) in 2017, and decreasing resistance to gatifloxacin and thiamphenicol were observed, from 76.78% (926/1 206) and 60.28% (727/1 206) in 2010 decreased to 34.23% (968/2 828) and 37.87% (1 071/2 828) in 2017, respectively. The resistance rate of Mh to gatifloxacin and thiamphenicol were decreased, from 68.93% (122/177) and 41.81% (74/177) in 2010 to 53.54% (159/297) and 21.21% (63/297) in 2017, respectively.@*Conclusions@#Doxycycline, minocyclinum and josamycin are good treatment options for genital mycoplasma in Changsha. The resistance rate of Uu to azithromycin is increasing, suggesting that the abuse of azithromycin is present in Changsha, and indicating that better management of antibiotics is necessary.

Research progress of long noncoding RNA in regulating adipogenesis / 中南大学学报(医学版)

Long noncoding RNA (lncRNA) is once thought to be the genome transcriptional "noise". However, it has received considerable attention in the past few years and is emerging as potentially important player in biological regulation. Recent studies have revealed that increasing number of lncRNA plays pivotal roles in regulating the gene expression which involves in the development of the human disease. Functions of lncRNA include 3 types of interaction: RNA-RNA, RNA-DNA, and RNA-protein, which may participate in gene expression regulation through epigenetic modifications, transcriptional regulation, post-transcriptional regulation, acting as biological media. Due to the prevalence of obesity and related diseases, some attempts have been done to explore the pathogenesis of obesity from the field of noncoding RNA. Several lncRNAs have been identified to be involved in the regulation of the adipogenesis (white adipose tissue and brown adipose tissue) and energy metabolism. In this review, we summarized recent advances of lncRNAs to provide a new sight for the mechanism of obesity.