Objective To obtain M. Tuberculosis Ag85A protein by prokaryotic expression. Methods The fbpA gene encoding M. Tuberculosis Ag85A protein was amplified by polymerase chain reaction ( PCR) from M. Tuberculosis H37R_V strain. The PCR product was cloned into prokaryotic expression vector pProEXHTb to generate the recombi-nant plasmid pProfbpA, which was then transformed into the competence Escherichia coli BL21 cells. The recombi-nant Ag85A protein was successfully expressed by isopropyl thio-β-D-galactoside(IPTG) induction and purified by the Ni-purification system. The distribution of fbpA gene in different nonpathogenic mycobacterial strains was screened by PCR and ELISA was performed to determine the immunoreactivity of the recombinant Ag85A protein with serum from mice with mycobacterial infections. Results 32 ku Ag85A protein was successfully expressed and purified. It was confirmed by PCR and ELISA that fbpA gene presented in the genomes of M. Tuberculosis H37Rv, H37Ra, BCG, M. Smegmatis, M. Terra, M. Trivial and M. Phlei, but being absent in the genomes of M. Vaccae. The highest Ag85 A antibody titer was found in serum of TB patients and mice infected by M . Tuberculosis H37Rv .Conclusion The recombinant Ag85A protein was successfully expressed and purified.

Coronavirus disease 2019(COVID-19),which is caused by SARS-CoV-2,varies with regard to symptoms and mortality rates among populations.Humoral immunity plays critical roles in SARS-CoV-2 infection and recovery from COVID-19.However,differences in immune responses and clinical features among COVID-19 patients remain largely unknown.Here,we report a database for COVID-19-specific IgG/IgM immune responses and clinical parameters(named COVID-ONE-hi).COVID-ONE-hi is based on the data that contain the IgG/IgM responses to 24 full-length/truncated proteins corresponding to 20 of 28 known SARS-CoV-2 proteins and 199 spike protein peptides against 2360 serum samples collected from 783 COVID-19 patients.In addition,96 clinical parameters for the 2360 serum samples and basic information for the 783 patients are integrated into the database.Furthermore,COVID-ONE-hi provides a dashboard for defining samples and a one-click analysis pipeline for a single group or paired groups.A set of samples of interest is easily defined by adjusting the scale bars of a variety of parameters.After the"START"button is clicked,one can readily obtain a comprehensive analysis report for further interpretation.COVID-ONE-hi is freely available at www.COVID-ONE.cn.