Development and characterization of anti-HPV16 monoclonal antibodies for assembly of an HPV16 detection kit.

Quality control is very important during the development of 3-valent (16/18/58), 9-valent (6/11/16/18/31/33/45/52/58), and 15-valent human papillomavirus (HPV) vaccines (6/11/16/18/31/33/35/39/45/52/56/58/59/68). All 3-valent, 9-valent, and 15-valent HPV vaccines contain the HPV16 antigen; therefore, a detection method that can specifically identify HPV16 in vaccines is urgently required. This study aimed to develop and characterize monoclonal antibodies to assemble a highly specific HPV16 detection kit. The HPV16 L1 pentameric protein developed as an immunogen was used to prepare monoclonal antibodies. From the pool of prepared monoclonal antibodies, we selected 4G12 and 5A6 to screen and evaluate their subtypes, specificity, neutralizing activity, serum competition, binding affinity, and gene sequencing. After these characterizations, an enzyme-linked immunosorbent assay kit for these monoclonal antibodies was developed, and excellent quality was demonstrated in the assessment of linearity, repeatability, and specificity. The developed detection kit has great potential for wide use in clinical testing and quality control in vaccine production processes.

Development of HPV58 type-specific antibodies and detection kit.

Currently, human papillomavirus (HPV) vaccines are in short supply, so the development of HPV vaccines has a broad market prospect. The 3-, 9-, and 15-valent HPV vaccines developed by ourselves all contain HPV58-derived antigen components. It is important to detect HPV 58 during vaccine production. Here, we introduced a development process of HPV58 type-specific antibodies and a detection kit. Briefly, HPV58 L1-Virus Like Particles (VLPs) were used as antigens to immunize mice, followed by extraction of the ascites to prepare hybridoma cells. After culturing, the supernatants containing secreted antibodies were harvested, purified, and screened to obtain monoclonal antibodies (mAbs). In the pool of attained monoclonal antibodies, we selected 2F7 and 2G7 to evaluate their subtypes, specificity, neutralizing activity, serum competition, binding affinity and gene sequencing. Finally, an enzyme-linked immunosorbent assay (ELISA) detection kit was assembled with 2F7 and 2G7 mAbs which possessed high specificity to HPV58 L1-VLPs. The detection kit developed by 2F7 and 2G7 could be adopted to specifically detect HPV58 L1 protein with good linearity and detection range, which could be widely used in clinical testing and quality control in the production of HPV vaccines.Abbreviations: BSA: Bovine serum albumin; CDRs: Complementarity-determining regions; CV: Coefficient of variation; DTT: Dithiothreitol; ELISA: Enzyme-linked immunosorbent assay; HAT: Hypoxanthine-aminopterin-thymidine; HPV: Human Papillomavirus; IC50: 50% inhibition rate; IC90: 90% inhibition rate; mAbs: Monoclonal antibodies; VLP: Virus-like particle.

Predictive role of Glutathione S-transferases (GSTs) on the prognosis of osteosarcoma patients treated with chemotherapy.

OBJECTIVE: We conducted a comprehensive study to investigate the role of GSTM1, GSTTI and GSTP1 genetic variation involved in transport pathways in response to chemotherapy and clinical outcome of osteosarcoma. METHODS: A total of 146 patients were included in our study between January 2008 and December 2009. All the patients were followed up to death or January 2012. Genotyping of GSTM1, GSTT1 and GSTP1 was conducted in a 384-well plate format on the Sequenom MassARRAY platform. RESULTS: Sixty seven patients (45.9%) died during the follow-up period. The median age of patients was 14.2 years and ranged from 9.3 to 38.7 years. The median follow-up time was 29.6 months (range 5 to 60 months). Individuals with GSTP1 G/G genotype tended to live shorter than A/A genotype, and we found a significantly higher risk of death from osteosarcoma (adjusted HR=2.73, 95% CI=1.05-7.45). Individuals with the GSTP GG genotype were more likely to have a poor response to chemotherapy, with an OR of 2.73 (95%CI, 1.07-7.81). However, we did not find association of polymorphisms in GSTM1 and GSTT1 with response to chemotherapy and prognosis of osteosarcoma. CONCLUSION: Our study provides information for prediction of treatment outcome in clinical oncology. Due to the limited number of samples, the results of our study need to be confirmed by large sample size studies.

Immunogenicity and protective effects of recombinant bivalent COVID-19 vaccine in mice and rhesus macaques.

Coronavirus disease (COVID-19) is still spreading rapidly worldwide, and a safe, effective, and cheap vaccine is still required to combat the COVID-19 pandemic. Here, we report a recombinant bivalent COVID-19 vaccine containing the RBD proteins of the prototype strain and beta variant. Immunization studies in mice demonstrated that this bivalent vaccine had far greater immunogenicity than the ZF2001, a marketed monovalent recombinant protein COVID-19 vaccine, and exhibited good immunization effects against the original COVID-19 strain and various variants. Rhesus macaque challenge experiments showed that this bivalent vaccine drastically decreased the lung viral load and reduced lung lesions in SARS-CoV-2 (the causative virus of COVID-19)-infected rhesus macaques. In summary, this bivalent vaccine showed immunogenicity and protective efficacy that was far superior to the monovalent recombinant protein vaccine against the prototype strain and provided an important basis for developing broad-spectrum COVID-19 vaccines.

Development and characterization of an HPV18 detection kit using two novel HPV18 type-specific monoclonal antibodies.

BACKGROUND: HPV 18 is one of the most prevalent oncogenic types, only second to HPV 16, and included in the licensed vaccines on the market. In this study, we describe the production and characterization of a panel of monoclonal antibodies (mAb) to HPV18. METHODS: The immunocompetence of 1B1 and 4C2 mAbs for HPV L1 protein was evaluated by SDS-PAGE analysis, neutralization assays, affinity identification, and ELISA. The 1B1 and 4C2 genes were sequenced and analyzed. Finally, the detection kit with the two mAbs was assessed for linearity, repeatability and specificity. RESULTS: Both mAbs specifically recognized HPV18 L1 and virus-like particles (VLPs). These mAbs are conformation-neutralizing antibodies that have high affinity and type specificity. Based on these characteristics of these mAbs, we developed an ELISA kit for specifically detecting HPV 18 antigen. We showed that this kit displayed good linearity, repeatability and sensitivity for detecting HPV18 L1 pentamer and HPV18 VLP. CONCLUSIONS: We characterized two monoclonal neutralizing antibodies for HPV L1 protein, and developed an ELISA kit for specifically detecting HPV 18 antigen. This newly developed kit can be used to monitor the potency of HPV vaccines throughout the entire production process as well as preliminary analysis of HPV18 infections.