Identification of potent human neutralizing antibodies against SARS-CoV-2 implications for development of therapeutics and prophylactics.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that is spreading rapidly, which seriously impacts global public health and economy. Thus, developing effective drugs remains urgent. We identify two potent antibodies, nCoVmab1 and nCoVmab2, targeting the SARS-CoV-2 spike protein receptor-binding domain (RBD) with high affinities from a naïve human phage-displayed Fab library. nCoVmab1 and nCoVmab2 neutralize authentic SARS-CoV-2 with picomolar and nanomolar IC50 values, respectively. No detectable defects of nCoVmab1 and nCoVmab2 are found during the preliminary druggability evaluation. nCoVmab1 could reduce viral titer and lung injury when administered prophylactically and therapeutically in human angiotensin-converting enzyme II (hACE2)-transgenic mice. Therefore, phage display platform could be efficiently used for rapid development of neutralizing monoclonal antibodies (nmabs) with clinical potential against emerging infectious diseases. In addition, we determinate epitopes in RBD of these antibodies to elucidate the neutralizing mechanism. We also convert nCoVmab1 and nCoVmab2 to their germline formats for further analysis, which reveals the contribution of somatic hypermutation (SHM) during nCoVmab1 and nCoVmab2 maturation. Our findings not only provide two highly potent nmabs against SARS-CoV-2 as prophylactic and therapeutic candidates, but also give some clues for development of anti-SARS-CoV-2 agents (e.g., drugs and vaccines) targeting the RBD.

Immunoglobulin fragment F(ab')2 against RBD potently neutralizes SARS-CoV-2 in vitro.

COVID-19, which is caused by the emerging human coronavirus SARS-CoV-2, has become a global pandemic that poses a serious threat to human health. To date, no vaccines or specific antiviral drugs have been approved for the treatment of this disease in clinic. Herein, therapeutic antibodies for SARS-CoV-2 were obtained from hyperimmune equine plasma. First, a recombinant SARS-CoV-2 spike protein receptor-binding domain (RBD) was obtained in gram-level quantities through high-cell density fermentation of Chinese hamster ovary cells. Then, the binding of the RBD to the SARS-CoV-2 receptor, human angiotensin-converting enzyme 2, was verified by several biochemical methods. The efficacy of the RBD in triggering antibody response in vivo was subsequently tested in both mice and equines, and the results showed that the RBD triggered high-titer neutralizing antibody production in vivo. Immunoglobulin F(ab')2 fragments were prepared from equine antisera via removal of the Fc region from the immunoglobulins. Finally, a neutralization test with live virus demonstrated that RBD-specific F(ab')2 inhibited SARS-CoV-2 with an EC50 of 0.07 µg/ml and an EC80 of 0.18 µg/ml, showing a potent inhibitory effect on SARS-CoV-2. These results highlight RBD-specific equine immunoglobulin F(ab')2 fragment as a candidate for the treatment of SARS-CoV-2.

Characterization of two engineered dimeric Zika virus envelope proteins as immunogens for neutralizing antibody selection and vaccine design.

The envelope protein of Zika virus (ZIKV) exists as a dimer on the mature viral surface and is an attractive antiviral target because it mediates viral entry. However, recombinant soluble wild-type ZIKV envelope (wtZE) might preferentially exist as monomer (monZE). Recently, it has been shown that the A264C substitution could promote formation of dimeric ZIKV envelope protein (ZEA264C), requiring further characterization of purified ZEA264C for its potential applications in vaccine development. We also noted that ZEA264C, connected by disulfide bond, might be different from the noncovalent native envelope dimer on the virion surface. Because the antibody Fc fragment exists as dimer and is widely used for fusion protein construction, here we fused wtZE to human immunoglobulin G1 (IgG1) Fc fragment (ZE-Fc) for noncovalent wtZE dimerization. Using a multistep purification procedure, we separated dimeric ZEA264C and ZE-Fc, revealing that they both exhibit typical ß-sheet-rich secondary structures and stabilities similar to those of monZE. The binding activities of monZE, ZEA264C, and ZE-Fc to neutralizing antibodies targeting different epitopes indicated that ZEA264C and ZE-Fc could better mimic the native dimeric status, especially in terms of the formation of tertiary and quaternary epitopes. Both ZEA264C and ZE-Fc recognize a ZIKV-sensitive cell line as does monZE, indicating that the two constructs are still functional. Furthermore, a murine immunization assay disclose that ZEA264C and ZE-Fc elicit more neutralizing antibody responses than monZE does. These results suggest that the two immunogen candidates ZEA264C and ZE-Fc have potential utility for neutralizing antibody selection and vaccine design against ZIKV.

Diabetes in Shenzhen, China: epidemiological investigation and health care challenges.

BACKGROUND: Understanding epidemiological characteristics of diabetes in a specific population will potentially benefit prevention and control of diabetes and policy-making. This study aimed to investigate the prevalence and awareness of diabetes, as well as its pharmacological, non-pharmacological and primary care management in Shenzhen, China. METHODS: A cross-sectional study was conducted. We employed multistage cluster random sampling methods to select the participants. Face-to-face interview surveys were conducted to collect data. A total of 1676 participants completed the survey. RESULTS: We found that the prevalence of diabetes was 4.8%. The prevalence of impaired fasting blood glucose was 6.0%. The prevalence rates of both diabetes and impaired fasting blood glucose increased with age (P < 0.001), whereas hypertension was strongly associated with diabetes only (odds ratio (OR) = 1.93, 95% confidence interval (CI) 1.15-3.22). The awareness of diabetes was poor (51.9%) and 54.3% of diabetic patients were not being treated pharmacologically. Less than one-third of diabetic patients were undergoing non-pharmacological treatments. Primary care management of diabetes was recorded for only 11.1% of the patients. CONCLUSIONS: Although diabetes prevalence in Shenzhen is about a half that of the Chinese average, high prevalence of impaired fasting blood glucose imposes a public health threat and burden to the health care system. Approximately half of the subjects with diabetes are undiagnosed. Our findings highlight the need of public health efforts for primary and secondary prevention, as well as early detection of diabetes. Primary care may be crucial an improved access to medical services and better management of diabetes.

The pharmacological efficacy of the anti-IL17 scFv and sTNFR1 bispecific fusion protein in inflammation mouse stimulated by LPS.

Acute lung injury (ALI) is still a leading cause of morbidity and mortality in critically ill patients. Recently, our study found that a bispecific fusion protein treatment can ameliorate the lung injury induced by LPS. However, the molecular mechanisms which bispecific fusion protein ameliorates acute lung injury remain unclear. In this study, we found that the bispecific fusion protein treatment inhibited the nuclear transcription of NF-κB in confocal laser scanning fluorescence microscopy, the bispecific fusion protein exert protective effects in the cell model of ALI induced by lipopolysaccharide (LPS) via inhibiting the nuclear factor κB (NF-κB) signaling pathway and mediate inflammation. Moreover, the treatment of the bispecific fusion protein show its efficacy in animal models stimulated by LPS, the results of real-time PCR and ELISA demonstrate that bispecific fusion protein treatment effectively inhibited the over-expression of inflammatory cytokines(tumor necrosis factor α, interleukin 1ß and interleukin 17). In addition, LPS-challenged mice exhibited significant lung injury characterized by the deterioration of histopathology, which was meliorated by bispecific fusion protein treatment. Collectively, these results demonstrate that bispecific fusion protein treatment ameliorates LPS-induced ALI through reducing inflammatory cytokines and lung inflammation, which may be associated with the decreased the nuclear transcription of NF-κB. The bispecific fusion protein may be useful as a novel therapy to treat ALI.

A cross-sectional study of the prevalence, awareness, treatment and control of hypertension in Shenzhen, China.

OBJECTIVES: An understanding of the awareness, treatment and control of hypertension is helpful to guide decision-making regarding interventions to reduce the risk for diseases with hypertension as a key risk factor. This study aimed to estimate the prevalence, awareness, treatment, and control of hypertension in Shenzhen, China. METHODS: A cross-sectional study was conducted. We employed multistage cluster random sampling methods to select participants. A survey involving face-to-face interviews was conducted to collect the data. A total of 1676 participants finished the survey and formed the final analysis. RESULTS: We found that the prevalence of hypertension was 17.6%. The rates of hypertension awareness, treatment and control were 48.8%, 51.4% and 43.2% respectively. Only 6.8% hypertensives were found to be managed by community health centres. Compared with the female participants, the males were found to have higher rates of prevalence (19.7% vs 15.7%; OR 1.47, 95% CI 1.10 to 1.97) and awareness (42.9% vs 38.1%; OR 2.35, 95% CI 1.28 to 4.33), but lower rates of medication treatments (20.5% vs 30.2%; OR 0.83, 95% CI 0.05 to 0.92) and control (12.8% vs 23.0%; OR 0.45, 95% CI 0.21 to 0.96). Migrants were more likely to be aware of hypertension (32.5% vs 44.3%; OR 0.57, 95% CI 0.30 to 0.90), reduce their salt intake (8.8% vs 18.1%; OR 0.40, 95% CI 0.15 to 0.94), and undertake regular monitoring of hypertension (1.3% vs 11.0%; OR 0.14, 95% CI 0.02 to 0.92) when compared with the locals. CONCLUSIONS: Our study finds that hypertension is an important public health burden in Shenzhen. It implies that strategies need to be developed to improve effective primary care management of hypertension. It also suggests a need to develop gender and household register tailored strategies for the prevention, detection, treatment and control of hypertension.

[Interaction between smoking and nicotine acetylcholine receptor subunits alpha 5 gene rs17486278 polymorphisms on lung cancer].

OBJECTIVE: To investigate the association and interaction between smoking and the nicotine acetylcholine receptor subunits alpha 5(CHRNA5) gene polymorphisms on lung cancer in Chinese men. METHODS: A case-control study was employed with a total of 204 male lung cancer patients and 821 healthy control subjects enrolled in the study. All the subjects were interviewed under a structured questionnaire with the contents on socio-demographic status and smoking behavior. Venous blood samples were collected to measure single nucleotide polymorphism of rs17486278 in CHRNA5. A series of multivariate logistic regression models were performed to assess the association and interaction between smoking and the CHRNA5 gene polymorphisms on lung cancer. RESULTS: After controlling for potential confounding factors, data from the multivariate logistic regression analysis showed that individuals with smoking >15 cigarettes per day would significantly increase the risk of lung cancer when compared to the non-smokers (OR = 3.49, 95%CI:2.29-5.32). However, no associations between CHRNA5 rs17486278 polymorphisms and lung cancer were found. Furthermore, those who smoked 1-15 cigarettes per day had a positive interactive effect between rs17486278 CC genotype and lung cancer (OR = 16.13, 95% CI:1.27-205.33). Results from further stratified analysis on smoking behaviors and rs17486278 genotypes indicated that when compared with non-smokers on rs17486278 AA genotype, those individuals who smoked 1-15 cigarettes per day with rs17486278 CC genotype, individuals smoking >15 cigarettes per day with AA genotype and individuals smoking >15 cigarettes per day with AC genotype, all had a higher risk of developing lung cancer, with their OR value as 8.14(95% CI:1.17-56.56), 3.84 (95% CI:1.30-11.40) and 5.32 (95% CI:1.78-15.93), respectively. CONCLUSION: There was an interaction between smoking and CHRNA5 gene polymorphism on lung cancer.