Isolating multiple formats of human monoclonal neutralizing antibodies against SARS-CoV-2 by in vitro site-directed antibody screening

Neutralizing antibody is one of the most effective interventions for acute pathogenic infection. Currently, over three million people have been identified for SARS-CoV-2 infection but SARS-CoV-2-specific vaccines and neutralizing antibodies are still lacking. SARS-CoV-2 infects host cells by interacting with angiotensin converting enzyme-2 (ACE2) via the S1 receptor-binding domain (RBD) of its surface spike glycoprotein. Therefore, blocking the interaction of SARS-CoV-2-RBD and ACE2 by antibody would cause a directly neutralizing effect against virus. In the current study, we selected the ACE2 interface of SARS-CoV-2-RBD as the targeting epitope for neutralizing antibody screening. We performed site-directed screening by phage display and finally obtained one IgG antibody (4A3) and several domain antibodies. Among them, 4A3 and three domain antibodies (4A12, 4D5, and 4A10) were identified to act as neutralizing antibodies due to their capabilities to block the interaction between SARS-CoV-2-RBD and ACE2-positive cells. The domain antibody 4A12 was predicted to have the best accessibility to all three ACE2-interfaces on the spike homotrimer. Pseudovirus and authentic SARS-CoV-2 neutralization assays showed that all four antibodies could potently protect host cells from virus infection. Overall, we isolated multiple formats of SARS-CoV-2-neutralizing antibodies via site-directed antibody screening, which could be promising candidate drugs for the prevention and treatment of COVID-19.

Relationship between Alzheimer's disease and mitochondria coenzyme II Gene.

We aimed to investigate the relevance between Alzheimer's disease (AD) and gene mutations of mitochondrial cytochrome oxidase subunit III (COX3) and coenzyme II (ND2), and to provide genetic markers for the diagnosis of Alzheimer's disease (AD) and further provide some feasible basis for preventive treatment. Polymerase chain reaction-restriction fragment length polymorphism technique was used, and genotypes and gene frequencies were detected in 60 patients with Alzheimer's disease (AD), who meet the ICD-10 diagnostic criteria (AD group), 10 AD families and 60 normal old people (control group). (1) Gene variation on nt5460 gene locus of mitochondria ND2 of the patient group is G→A, and the variation rate is 13.3%, P=0.006 < 0.05. Gene variation G→A of the patient group perfomred statistical significance. (2) In the families, it is also found that in the gene variation of G→A, the variation rate is 33.3%, P > 0.05. There is obvious gene variation in the families, but this variation does not perform statistical significance. (3) There is no gene variation on nt9861 gene locus of mitochondria COX3 of the patient group. Gene variation of T→C is not found both in the patient group and the control group. There is possible a gene mutation of G→A on nt5460 gene locus of mitochondria ND2 of the AD patients. Although gene mutation of G→A is found in the families, it performed no statistical significance. At the same time, it is found that there is no relation between AD patients and Gene variation of T→C on nt9861 gene locus of mitochondria COX3.

Roles of PIK3R1 gene in development of hepatocellular carcinoma / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the roles of phosphatidylinositol 3 kinase regulatory subunit alpha (PIK3R1）gene in the development of hepatocellular carcinoma （HCC）.</p><p><b>METHODS</b>Surgical specimens of liver cancer and corresponding pericancerous liver tissue were collected from 20 patients with hepatocellular carcinoma. Expression of p85α, encoded by PIK3R1, in HCC tissue specimens was detected by Western blotting and immunohistochemistry. HCC HepG2 cells were transfected with PIK3R1 siRNA or PIK3R1-cDNA. The expression of PIK3R1 in transfected HepG2 cells or control cells were detected by real-time PCR. Cell proliferation was evaluated by MTT, colony formation assays and flow cytometry respectively. The expression of PI3K/AKT pathway-related proteins were detected by Western blotting.</p><p><b>RESULTS</b>The expression of p85α in liver tissue was higher than that in pericancerous tissues (1.27±0.58 vs 0.99±0.47，t=-3.25，P<0.05）. The expression of PIK3R1 was decreased by 0.19±0.03 fold in PIK3R1siRNA-transfected HepG2 cells(t=46.77，P<0.05)，and increased by 32.36±3.33 fold in PIK3R1 cDNA -transfected cells（t=-16.31， P<0.05）. MTT result showed that PIK3R1 siRNA inhibited growth of HepG2 cells （0.611±0.072 vs 0.807±0.059，t=3.65，P<0.05），while PIK3R1 cDNA increased the cell growth（0.937±0.060 vs 0.693±0.065，t=-4.78，P<0.05）. PIK3R1 siRNA transfected cells presented lower colony-forming efficiency than control group（3.8%±0.84% vs 15.0%±2.3%，t=7.92，P<0.05），while PIK3R1 cDNA transfected cells had higher colony-forming efficiency than control group (23.6%±3.4% vs 12.0%±1.5%，t=-5.40，P<0.05）. PIK3R1 siRNA reduced the ratio of S phase cells（13.9%±0.015% vs 32.9%±0.07%，t=45.97，P<0.01, while PIK3R1 cDNA increased S phase cells（56.33%±0.024% vs 31.94%±0.042%，t=-8.73，P<0.01）. PIK3R1 increased the level of p-AKT and decreased p53 level. CONCLUSION：p85α is highly expressed in HCC，and PIK3R1 gene may promote proliferation of HepG2 cells by activating PI3K/AKT pathway.</p>

Association study between schizophrenia and polymorphism of phosphoserine aminotransferase 1gene / 中华行为医学与脑科学杂志

ObjectiveTo detect the association between schizophrenia and polymorphism of phosphoserine aminotransferase 1 ( PSAT1 ) gene.MethodsThe study group included 158 patients with schizophrenia from Xi' an Mental Health Center and the control group included 316 parents.The polymorphism of rs69287125,rs137824326 of phosphoserine aminotransferase 1 gene was detected with PCR methods and SNP typing in all nucleus families by correlation analysis and haplotype relative risk analysis.ResultsThe rs69287125 allele was associated with schizophrenia (P=0.011 ),the G allele was protective factor (Z =-2.31 ) and the A allele was hazarding factor (Z =2.31 ).The rs137824326 allele was associated with schizophrenia (P=0.007 ),the G allele was protective factor ( Z =- 2.54) and the A allele was the hazarding factor( Z =2.54).The haplotypes of A/A and G/G in the rs69287125-rs137824326 were associated with schizophrenia (P =0.021,0.015,Z =2.16,- 1.85).ConclusionThe polymorphism of phosphoserine aminotransferase 1 gene is associated with schizophrenia in Chinese.

Association study of schizophrenia and phosphodiesterase 4B gene polymorphism / 中华行为医学与脑科学杂志

Objective To detect the genetic association between schizophrenia and polymorphism of phosphodiesterase 4B (PDE4B) gene. Methods Observed in a sample of 98 parent/offspring trios where the proband net the Amerecan Classification and diagnostic Criteria for Mental Disorders The Forth Revised Edition,criteria for schizophrenia using correlation analysis and haplotype relative risk analysis. The polymorphism of phosphodiesterase 4B gene was detected with PCR methods and SNP typing in all nucleus families. Results The rs2180335 al-lele was connected with schizophrenia (P = 0.02131). Allele A was protective factor (Z = -2. 184) and allele G was the hazard factor (Z = 2.184). The frequency of rs2180335 allele A was 0.452 and the allele G was 0.548. The rs1040716, rs 3767311 and rs472952 allele was independence with schizophrenia. Five kinds haplotypes of A/A in the rs2180335-rs3767311, A/A in the rs 3767311-rs472952, A/A/A in the rs2180335-rs3767311-rs472952,A/G/G/A and T/A/A/A in the rs1040716-rs2180335-rs3767311-rs472952 associated with schizophrenia (P values were 0. 028715,0. 034845,0. 024177,0. 023967,0. 010839,genotype frequencies were 0. 223, 0.223,0.127,0.081,0.073). Conclusion It shows an association between schizophrenia and the rs2180335 polymorphism at nucleotide of phosphodiesterase 4B gene in Chinese.

Association study of schizophrenia and ankyrin repeat and kinase domain containing 1 gene polymorphism / 中华行为医学与脑科学杂志

Objective To detect the genetic association between schizophrenia and polymorphism of Ankyrin repeat and kinase domain containing 1 ( ANKK1 ) gene. Methods Observed in a sample of 112 parent/offspring trios where the proband net the American Classification and diagnostic Criteria for Mental Disorders The Forth Revised Edition, criteria for schizophrenia using correlation analysis and haplotype relative risk analysis. The polymorphism of Ankyrin repeat and kinase domain containing 1 gene was detected with PCR methods and SNP typing in all nucleus families. Results The rs2734849 allele was connected with schizophrenia(P= 0. 026). Allele T was protective factor( Z= -2.19) and allele A was the hazard factor( Z=2. 19). The rs4938015,rs7118900 and rs1800497 allele were independence with schizophrenia. Three kinds haplotypes of G/A in the rs7118900 -rs2734849, A/C in the rs2734849 -rs1800497, G/A/C in the rs7118900 -rs2734849 -rs1800497 were associated with schizophrenia ( The P values were 0.032,0. 041,0.046, the genotype frequencies were 0. 36,0.29,0. 17 ).Conclusion It shows an association between schizophrenia and the polymorphism at nucleotide of ankyrin repeat and kinase domain containing 1 gene in Chinese.