ABSTRACT
An excessive immune response contributes to SARS-CoV, MERS-CoV and SARS-CoV-2 pathogenesis and lethality, but the mechanism remains unclear. In this study, the N proteins of SARS-CoV, MERS-CoV and SARS-CoV-2 were found to bind to MASP-2, the key serine protease in the lectin pathway of complement activation, resulting in aberrant complement activation and aggravated inflammatory lung injury. Either blocking the N protein:MASP-2 interaction or suppressing complement activation can significantly alleviate N protein-induced complement hyper-activation and lung injury in vitro and in vivo. Complement hyper-activation was also observed in COVID-19 patients, and a promising suppressive effect was observed when the deteriorating patients were treated with anti-C5a monoclonal antibody. Complement suppression may represent a common therapeutic approach for pneumonia induced by these highly pathogenic coronaviruses. One Sentence SummaryThe lectin pathway of complement activation is a promising target for the treatment of highly pathogenic coronavirus induced pneumonia.
ABSTRACT
Recent studies find that the expression of hepatoma-derived growth factor (HDGF) is closely correlated with the tumorigenesis,progression,metastasis,therapy and prognosis of various malignancies.Though the mechanism of the interaction of HDGF and tumors is still unclear,the research of HDGF serving as a tumor marker in malignancies and a new target for tumor treatment has become a hotspot in the research of tumor.
ABSTRACT
Fibrinogen (Fib) is one of the most common coagulation proteins,plays an important role in the coagulation cascade,and has a closed relationship with tumor.Studies indicate that the level of Fib has elevated in many kinds of cancer,and Fib is also closely correlated with the progression,metastasis and prognosis of tumor.Though the mechanism of the interaction of Fib and tumor is still unclear,Fib as a tumor marker and new therapy for these malignancies has been a new hotspot.
ABSTRACT
Objective To detect the immune effect of FbaAmAb2 against the surface protein of group A Straptococcus (GAS),and explore the pathogenesis and therapy of GAS infections.Methods By subclonal and bacterial ELISA,the positive hybridoma cells were screened that can produce better titers of FbaAmAb2 against GAS-surface FbaA protein,and were injected into the peritoneal cavities of BALB/c mice to produce ascites.The collected ascites were performed to dilute,as follows,original ascite,1:2,1:4,1:8,and 1:16 to test tube agglutination.Based on the results,we selected appropriate dilution to passively immunize mice,and then challenged the mice with GAS,evaluating FbaAmAb2 neutralizing ability with GAS in mice by the survival rate of the immunized mice.Whether FbaAmAb2 could inhibit the binding of factor H to GAS was confirmed by the invasive inhibition assay.Results The IgG titer of bacteria solution ELISA is 1:160 and the titer of tube agglutination is 1∶8.The protect rates of FbaAmAb2 on preventing mice with GAS infections are as follows:66.67％ in original ascite and 1:2 diluted groups,and 50％ in 1:4 diluted group.Mice in each experimental group were evoked significantly protective immune responses compared with the PBS control by SPSS analysis.FbaAmAb2 can competitively inhibit factor H binding to the surface proteins FbaA of GAS,which decreased the entry of GAS into the cytoplasm of human epithelial cells through the binding of factor H.Conclusion FbaAmAb2 is promising to be used in emergent prevention or the clinical therapy for GAS infection and it is promising starting points for pharmacologic targeting and further development of new therapeutic agents for GAS.
