Identification of four linear B-cell epitopes on the SARS-CoV-2 spike protein able to elicit neutralizing antibodies

SARS-CoV-2 unprecedentedly threatens the public health at worldwide level. There is an urgent need to develop an effective vaccine within a highly accelerated time. Here, we present the most comprehensive S-protein-based linear B-cell epitope candidate list by combining epitopes predicted by eight widely-used immune-informatics methods with the epitopes curated from literature published between Feb 6, 2020 and July 10, 2020. We find four top prioritized linear B-cell epitopes in the hotspot regions of S protein can specifically bind with serum antibodies from horse, mouse, and monkey inoculated with different SARS-CoV-2 vaccine candidates or a patient recovering from COVID-19. The four linear B-cell epitopes can induce neutralizing antibodies against both pseudo and live SARS-CoV-2 virus in immunized wild-type BALB/c mice. This study suggests that the four linear B-cell epitopes are potentially important candidates for serological assay or vaccine development.

Recombinant Fc-fusion vaccine of RBD induced protection against SARS-CoV-2 in non-human primate and mice

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) continues to infect people globally. The increased COVID-19 cases and no licensed vaccines highlight the need to develop safe and effective vaccines against SARS-CoV-2 infection. Multiple vaccines candidates are under pre-clinical or clinical trails with different strengths and weaknesses. Here we developed a pilot scale production of a recombinant subunit vaccine (RBD-Fc Vacc) with the Receptor Binding Domain of SARS-CoV-2 S protein fused with the Fc domain of human IgG1. RBD-Fc Vacc induced SARS-CoV-2 specific neutralizing antibodies in non-human primates and human ACE2 transgenic mice. The antibodies induced in macaca fascicularis neutralized three divergent SARS-CoV2 strains, suggesting a broader neutralizing ability. Three times immunizations protected Macaca fascicularis (20ug or 40ug per dose) and mice (10ug or 20ug per dose) from SARS-CoV-2 infection respectively. These data support clinical development of SARS-CoV-2 vaccines for humans. RBD-Fc Vacc is currently being assessed in randomized controlled phase 1/II human clinical trails. SummaryThis study confirms protective efficacy of a SARS-CoV-2 RBD-Fc subunit vaccine.

Rapid adaptation of SARS-CoV-2 in BALB/c mice: Novel mouse model for vaccine efficacy

Coronavirus disease 2019 (COVID-19) threatens global public health and economy. In order to develop safe and effective vaccines, suitable animal models must be established. Here we report the rapid adaption of SARS-CoV-2 in BALB/c mice, based on which a convenient, economical and effective animal model was developed. Specifically, we found that mouse-adapted SARS-CoV-2 at passage 6 (MACSp6) efficiently infected both aged and young wild-type BALB/c mice, resulting in moderate pneumonia as well as inflammatory responses. The elevated infectivity of MACSp6 in mice could be attributed to the substitution of a key residue (N501Y) in the receptorbinding domain (RBD). Using this novel animal model, we further evaluated the in vivo protective efficacy of an RBD-based SARS-CoV-2 subunit vaccine, which elicited highly potent neutralizing antibodies and conferred full protection against SARS-CoV-2 MACSp6 challenge. This novel mouse model is convenient and effective in evaluating the in vivo protective efficacy of SARS-CoV-2 vaccine. SummaryThis study describes a unique mouse model for SARS-CoV-2 infection and confirms protective efficacy of a SARS-CoV-2 RBD subunit vaccine.

Endocan reduces the malign grade of gastric cancer cells by regulating associated protein expression.

Endocan, which has been identified to be low expressed in gastric cancer, was found to be positively related to the differentiation level of gastric cancer in vivo and in vitro. In the present study, we aimed to investigate the role of endocan in gastric adenocarcinoma cell line SGC7901 by artificially upregualting or downregulating endocan expression using endocan recombinant vector or specific small interfering RNA (siRNA)-targeting endocan gene, respectively. The effects of endocan recombinant vector-mediated over-expressing and siRNA-mediated endocan silencing on the differentiation, migration, and apoptosis of SGC7901 cells were assessed. Furthermore, the primary molecular mechanisms of endocan were explored by testing the expression alterations of associated protein in SGC7901 along endocan over-expression or knockdown. We found that over-expression of endocan reduced the migration but promoted the differentiation and apoptosis of SGC7901 cells. While, knockdown of endocan did just the opposite. Some molecules were found to participate in endocan-mediated anti-tumor effects, such as p53, caspase 3, and MMP-9. In conclusion, our findings suggest that endocan plays an anti-carcinogenic role in gastric cancer development and progression and might serve as a prognostic biomarker as well as a potential therapeutic target for gastric cancer.

Research progress in combination therapy with pegylated interferon and nucleos(t)ide analogues in treatment of chronic hepatitis B / 临床肝胆病杂志

Current antiviral treatment strategy for chronic hepatitis B (CHB) includes pegylated interferon (PEG-IFN) and nucleos(t)ide analogues (NAs). Whether combination therapy with PEG-IFN and NAs improve therapeutic efficacy has become the key question regarding the antiviral therapy for CHB. This article reviews the recent progress in combination therapy for the management of CHB. The results indicate that the efficacy of simultaneous combination of PEG-IFN and NAs is not superior to that of PEG-IFN monotherapy in terms of HBeAg seroconversion and response after drug withdrawal. Sequential combination or switching therapy in PEG-IFN- or NAs-treated patients, as well as combination with immune cell therapy, is a promising treatment strategy.

Dynamic expressions of kielin/chordin-like protein in mouse model of liver fibrosis and changes after bone morphogenetic protein-7 intervention / 中华传染病杂志

Objective To observe the dynamic expressions of kielin/chordin-like protein (kcp) in mouse model of hepatic fibrosis and the effects of bone morphogenetic protein-7 (BMP-7)intervention on the expressions,and to explore a new target for treatment of fibrosis.Methods A total of 50 healthy male ICR mice were divided into three groups:control group(n=10) ; model group (n=30) and BMP-7 treatment group (n=10).The model group was further divided into three subgroups according to different time points:subgroups of 4,8 and 12 weeks with 10 mice in each subgroup.The mouse model of hepatic fibrosis was established by hypodermic injection of carbon tetrachloride(CCl4 ).The mice in BMP-7 treatment group began to receive human recombmant BMP- 7via intraperitoneal injection after 8 weeks of the first administration of CC14 and lasted for 4 weeks.The serum levels of alanine aminotransferase (ALT),aspartate transaminase (AST) and albumin (Alb) were detected.The pathological changes of liver were observed under optical microscope after HE and Masson staining.The dynamic expressions of kcp mRNA and protein of each group were detected by reverse transcription-polymerase chain reaction,immunohistochemistry and Western blot.The comparison of means among groups was done by univariate ANOVA.Results In model group,ALT and AST levels increased,while Alb level gradually decreased,and peaked at week 12.BMP-7treatment could reduce the changes,and there were significant differences among groups (F=23.501,34.600 and 16.244,respectively; all P＜0.05).In normal control group,the expressions of kcp mRNA and protein were low,while those in model group were gradually increased.BMP-7 treatment could achieve remission and the changes were all significantly different among groups (F=30.362 and 10.727,respectively; P＜0.01 or 0.05).The expression of kcp mRNA was positively correlated with levels of transforming growth factor (TGF)-β1 mRNA and BMP-7 mRNA (r=0.760 and 0.769,respectively; both P＜0.05).Conclusions BMP 7 can improve the hepatic fibrosis in mice.kcp may play an important role in the occurrence and development of liver fibrosis which is a potential therapeutic target for hepatic fibrosis.

CT Analysis of Solitary Thyroid Cystic Lesions:A Report of 48 Cases / 实用放射学杂志

Objective To study the CT findings and differential diagnosis of solitary thyroid cystic lesions.Methods 48 cases of solitary thyroid cystic lesions confirmed pathologically were analysed retrospectively.Results According to the CT findings,the lesions could be divided into there types:type Ⅰ simple cyst(n=35),type Ⅱ cyst with nodule on the wall(n=4) and type Ⅲ cyst with thick wall and/or round mass on it(n=9).The enhanced ring appeared in thyroid adenomas was complete(n=25) in comparison with the enhanced ring was fragmentary appeared in thyroid carcinoma(n=2),double circle enhanced ring appeared in abscess(n=2).Type Ⅰ more common appeared in benign lesions(35/35) in comparison with type Ⅱ in malignant lesions(7/9)(P

CONSTITUENT ANALYSIS AND CONTENT DETERMINATION OF FATTY ACIDS AND SQUALENE OF SHARK LIVER OIL / 中国海洋药物

Reported in this paper is the constituent analysis of shark Carcharhinus latistomus from China by gas chromatography/mass spectrometry. Squalene and fifteen kinds of fatty acids were identified,the contents of squaiene and fatty acids were determined.