ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause acute respiratory distress syndrome, hypercoagulability, hypertension, and multiorgan dysfunction. Effective antivirals with safe clinical profile are urgently needed to improve the overall prognosis. In an analysis of a randomly collected cohort of 124 patients with COVID-19, we found that hypercoagulability as indicated by elevated concentrations of D-dimers was associated with disease severity. By virtual screening of a U.S. FDA approved drug library, we identified an anticoagulation agent dipyridamole (DIP) , which suppressed SARS-CoV-2 replication . In a proof-of-concept trial involving 31 patients with COVID-19, DIP supplementation was associated with significantly decreased concentrations of D-dimers ( < 0.05), increased lymphocyte and platelet recovery in the circulation, and markedly improved clinical outcomes in comparison to the control patients. In particular, all 8 of the DIP-treated severely ill patients showed remarkable improvement: 7 patients (87.5%) achieved clinical cure and were discharged from the hospitals while the remaining 1 patient (12.5%) was in clinical remission.
ABSTRACT
The spike (S) and nucleocapsid (N) proteins, which are responsible for viral binding to cell surface receptors and the formation of ribonucleoprotein complexes during virion assembling, are major structure proteins of severe acute respiratory syndrome coronavirus (SARS-CoV). The expression of recombinant protein may give more accurate result for detecting SARS-CoV infection. A novel fusion protein,comprising of two fragments of N and S proteins from SARS-CoV, was prepared. Our computer-assisted analysis suggested that the immunodominant domains were located in the amino acid residues 1-227 of N protein and 450-650 of S protein, further the fusion of the two fragments did not change the immunochemical characteristics. The complementary DNA(cDNA) encoding N1-227 fused with S450-650 was obtained by sequence overlapping extension (SOE), and named NLS. It was cloned into pET-28a ( + ), an expression vector for His-tag fusion protein. This new constructed fusion protein was prokaryotic expressed in E. coli,and purified by metal chelate affinity chromatography with the purity over 95 %. The purified fusion protein was identified by anti-His monoclonal antibody and convalescence SARS patients serum. The NLS protein based ELISA showed that NLS maintained appropriate antigenicity and specificity to react with the sera of convalescent SARS patients. The functional NLS protein were successfully expressed and purified. And the fusion protein based ELISA can be used for detection of antibodies (Abs) against the S and N proteins of SARS-CoV. It may provided a novel diagnostic tool and have the potential application in developing of anti-SARS vaccine.
ABSTRACT
Objective:To establish and characterize human CD4 +CD25 + T cell lines Methods:CD4 +CD25 + T cells were isolated from healthy volunteers and expanded in vitro Their suppressive effect on the proliferation of CD4 + T cells was analyzed in proliferation assays Phenotype of the T cell lines was determined by FACS Results:Long term cultured CD4 +CD25 +T cells were hyporesponsive to stimulation via their T cell receptor In co culture experiments CD4 +CD25 + T cells could suppress the activation and proliferation of CD4 + T cells, and the suppression was abrogated when exogenous IL 2 was provided In vitro expanded human CD4 +CD25 + T cells remained positive for CD25 and CTLA 4 expression Conclusion:CD4 +CD25 + T cells can be established as long term cultured T cell lines while still maintaining their suppressive function and distinctive phenotype from CD4 +CD25 - T cells