Human antibody BD-218 has broad neutralizing activity against concerning variants of SARS-CoV-2.

As SARS-CoV-2 variants of concern (VOC) reduce the effectiveness of existing anti-COVID therapeutics, it is increasingly critical to identify highly potent neutralizing antibodies (nAbs) that bind to conserved regions across multiple variants, especially beta, delta, and omicron variants. Using single-cell sequencing with biochemical methods and pseudo-typed virus neutralization experiments, here we report the characterization of a potent nAb BD-218, identified from an early screen of patients recovering from the original virus. We have determined the cryo-EM structure of the BD-218/spike protein complex to define its epitope in detail, which revealed that BD-218 interacts with a novel epitope on the receptor-binding domain (RBD) of the spike protein.

Infectivity and antigenicity of pseudoviruses with high-frequency mutations of SARS-CoV-2 identified in Portugal.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a major impact on global human health. During the spread of SARS-CoV-2, weakened host immunity and the use of vaccines with low efficacy may result in the development of more-virulent strains or strains with resistance to existing vaccines and antibodies. The prevalence of SARS-CoV-2 mutant strains differs between regions, and this variation may have an impact on the effectiveness of vaccines.

Discovery and evolution of 12N-substituted aloperine derivatives as anti-SARS-CoV-2 agents through targeting late entry stage.

So far, there is still no specific drug against COVID-19. Taking compound 1 with anti-EBOV activity as the lead, fifty-four 12N-substituted aloperine derivatives were synthesized and evaluated for the anti-SARS-CoV-2 activities using pseudotyped virus model. Among them, 8a exhibited the most potential effects against both pseudotyped and authentic SARS-CoV-2, as well as SARS-CoV and MERS-CoV, indicating a broad-spectrum anti-coronavirus profile.

Cathepsin L plays a key role in SARS-CoV-2 infection in humans and humanized mice and is a promising target for new drug development.

To discover new drugs to combat COVID-19, an understanding of the molecular basis of SARS-CoV-2 infection is urgently needed. Here, for the first time, we report the crucial role of cathepsin L (CTSL) in patients with COVID-19. The circulating level of CTSL was elevated after SARS-CoV-2 infection and was positively correlated with disease course and severity.

A Thermostable mRNA Vaccine against COVID-19.

There is an urgent need for vaccines against coronavirus disease 2019 (COVID-19) because of the ongoing SARS-CoV-2 pandemic. Among all approaches, a messenger RNA (mRNA)-based vaccine has emerged as a rapid and versatile platform to quickly respond to this challenge. Here, we developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor binding domain (RBD) of SARS-CoV-2 as a vaccine candidate (called ARCoV).

A Mouse Model of SARS-CoV-2 Infection and Pathogenesis.

Since December 2019, a novel coronavirus SARS-CoV-2 has emerged and rapidly spread throughout the world, resulting in a global public health emergency. The lack of vaccine and antivirals has brought an urgent need for an animal model. Human angiotensin-converting enzyme II (ACE2) has been identified as a functional receptor for SARS-CoV-2.

Discovery and evolution of aloperine derivatives as novel anti-filovirus agents through targeting entry stage.

Preventing filoviruses in the entry stage is an attractive antiviral strategy. Taking aloperine, a Chinese natural herb with an endocyclic skeleton, as the lead, 23 new aloperine derivatives were synthesized and evaluated for their anti-filovirus activities including ebola virus (EBOV) and marburg virus (MARV) using pseudotyped virus model. Structure-activity relationship (SAR) analysis indicated that the introduction of a 12N-dichlorobenzyl group was beneficial for the potency.

Use of immuno-dominant epitope derived from genotype 4 as a diagnostic reagent for detecting the antibodies against Hepatitis E Virus.

Background: Despite the genotype 4 has become the dominant cause of hepatitis E disease in China, none antigen derived from genotype 4 of hepatitis E virus (HEV) was used in current commercial anti-HEV immunoassay, and the serological reactivity of antigen derive from genotype 4 is not well-charactered.

Methods: We expressed and purified the 4 main immuno-dominant epitopes derived from genotype 1 and 4 including ORF2 (410-621aa) of genotype 4, ORF3 (47-114aa) of genotype 4, ORF2 (396-606aa) of genotype 1 and ORF3 (56-123aa) of genotype 4.

Results: The ORF2 of genotype 4 displayed good diagnostics performance according to ROC analysis using in-house panel, and the immunoassays based the ORF2 of genotype 4 was then developed to detect the anti-HEV IgG antibodies and evaluated further in 530 anti-HEV IgG positive specimens and 380 negative specimens.

[Comparison between recombinant virus assay and live virus assay on evaluating anti-HIV-1 drugs].

Objective: To compaire results of recombinant virus assay and live virus assay on evaluateing anti-HIV-1 drugs.

Methods: The pseudoviruse was generated by cotransfection of the plasmid B01 containing gp160 genes and pSG3 delta env plasmid. After co-incubation of pseudovirus with serially diluted drug, the EC50 and ED50 were calculated according to RLU(relative light unit) for each drug.

Detection of HPV types and neutralizing antibodies in women with genital warts in Tianjin City, China.

The serum samples and corresponding cervical swabs were collected from 50 women with genital warts from Tianjin city, China. The neutralizing antibodies against HPV-16, -18, -58, -45, -6 and -11 in serum samples were tested by using pseudovirus-based neutralization assays and HPV DNAs in cervical swabs were also tested by using a typing kit that can detect 21 types of HPV. The results revealed that 36% (18/50) of sera were positive for type-specific neutralizing antibodies with a titer range of 160-2560, of which 22%(11/50), 12%(6/50), 10%(5/50), 4%(2/50), 4%(2/50) and 2%(1/50) were against HPVs -6, -16, -18, -58, -45 and -11, respectively.

[The impact of the HIV-1 envelope (Env) mutation on its assembly of functional pseudovirus].

To find out whether the mutations of HIV-1 Env have influence on the assembly of pseudovirus and their abilities to infect cells, site-directed mutation (A457D)was performed using cycling mutagenesis and selection of mutants with DpnI. Transformation and plasmid purification technologies were used to obtain mutated env clone. Then both the prototype and the mutant were co-transfected with pSG3(delta(env)) to 293FT cells, respectively.

[Comparison of the reliability of two ELISA kits for detecting IgM antibody against hepatitis E virus].

Objective: To study the reliability of two ELISA kits for detecting IgM antibody against hepatitis E virus (HEV).

Methods: Serum samples from 92 healthy subjects, 71 cases suspected of hepatitis E, 55 patients with confirmed diagnosis of acute hepatitis E, 50 individuals with rheumatoid factor (RF) positive and 54 persons with anti-HAV IgM positive were detected with three hepatitis E diagnostic kits. MP-IgM (MP, Singapore), Wantai-IgM and anti-HEV IgG (Wantai, China).

[The preliminary analysis on immunogenicity of DNA vaccines against human papillomavirus 58].

In order to evaluate the immunogenicity of HPV 58 L1 DNA vaccines, five DNA vaccines had been constructed with pcDNA3.1 vector containing different L1 genes of HPV 58, which were designated as L1h, L1hDeltac, L1S, L1SM and L1wt. The protein expression of DNA vaccines in vitro was tested by Western blot.

[Epidemiological survey on the infection of hepatitis E virus among pigs in Henan province].

Objective: To investigate hepatitis E virus (HEV) infection among pigs in Henan province.

Methods: A total of 623 swine sera, collected from 5 districts, were divided into two groups, under 3-month of age and over 3-month of age. They were tested for HEV antigen and antibody by using ELISAs, respectively.

[Expression of ORF2 protein of HEV genotype IV in Hansenula polymorpha].

Hepatitis E, an acute infectious disease transmitted via the fecal-oral route, is caused by hepatitis E virus. However, no effective treatment currently exists for hepatitis E, and the only epidemic control approach is vaccination. But so for there are no commercial vaccine for hepatitis E available in the world.

[A study on the prevalence rates of human immunodeficiency virus, hepatitis B virus and hepatitis C virus infections in intravenous drug users].

Objective: To study HIV, HBV and HCV infections in intravenous drug users.

Methods: 2025 blood samples from intravenous drug users were collected from Sichuan, Hunan, Guangxi and Xinjiang regions, and tested for anti-HIV, anti-HCV, HBsAg using enzyme-linked immuno-sobent assays (ELISAs).

Results: The positive rates of anti-HIV,anti-HCV and HBsAg were14.

[Evaluation of procleix HIV/HCV RNA diagnostic assay].

Background: To investigate the sensitivity and specificity of Procleix HIV/HCV RNA diagnostic assay.

Methods: HIV antibody positive or suspected positive plasmas of blood donors were collected from different provinces and detected with HIV antibody ELISA and HCV antibody ELISA. Samples positive for HIV by ELISA were confirmed by using HIV Blot.

[Expression of HBV S and preS1 fusion gene in Pichia pastoris expression system].

Background: To clone and express the ss1 recombinant gene containing S gene and preS1 (10-50 AA) gene in P. pastoris expression system.

Methods: The fusion gene ss1 containing the S (1-222 AA) gene and preS1 (10-50 AA) gene was constructed with PCR method.

[Establishment of the reference panel for HIV RNA].

Objective: To establish a national reference panel for HIV RNA diagnostic reagents.

Methods: Sera from patients with HIV infection and healthy blood donors were collected and tested for HIV and HCV antibodies and HBsAg by using ELISA. The HIV antibody positive samples with ELISA were confirmed with HIV Blot 2.

[Clinical significance of detecting RNA and anti HEV antibody in convalesent sera in patients with acute HEV hepatitis].

Objective: To investigate the anti hepatitis E virus (HEV) and HEV RNA in acute and convalescent sera of patients with NonA-E acute hepatitis.

Methods: The serum samples were taken from 95 patients who were diagnosed as acute NonA-E hepatitis. Enzyme immunoassay (EIA) was used for detecting anti-HEV Immunoglobulin G (IgG, Genolable and Wantai EIA anti-HEV kits).

[Development and preliminary application of monoclonal antibodies against N protein of SARS virus].

Objective: To develop the monoclonal antibody against N protein of SARS virus and study its applicability.

Methods: BALB/c mice were immunized with recombinant N protein. Spleen cells were collected and infused with SP2/0 cell.