RESUMO
Vaccines and therapeutics are urgently needed for the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we screen human monoclonal antibodies (mAb) targeting the receptor binding domain (RBD) of the viral spike protein via antibody library constructed from peripheral blood mononuclear cells of a convalescent patient. The CT-P59 mAb potently neutralizes SARS-CoV-2 isolates including the D614G variant without antibody-dependent enhancement effect. Complex crystal structure of CT-P59 Fab/RBD shows that CT-P59 blocks interaction regions of RBD for angiotensin converting enzyme 2 (ACE2) receptor with an orientation that is notably different from previously reported RBD-targeting mAbs. Furthermore, therapeutic effects of CT-P59 are evaluated in three animal models (ferret, hamster, and rhesus monkey), demonstrating a substantial reduction in viral titer along with alleviation of clinical symptoms. Therefore, CT-P59 may be a promising therapeutic candidate for COVID-19.
Assuntos
Anticorpos Neutralizantes/farmacologia , Tratamento Farmacológico da COVID-19 , Ligação Proteica/efeitos dos fármacos , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/efeitos dos fármacos , Enzima de Conversão de Angiotensina 2/química , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Chlorocebus aethiops , Modelos Animais de Doenças , Feminino , Furões , Humanos , Leucócitos Mononucleares , Macaca mulatta , Masculino , Mesocricetus , Modelos Moleculares , Conformação Proteica , Glicoproteína da Espícula de Coronavírus/química , Células VeroRESUMO
OBJECTIVE: To investigate the mechanism of vascular endothelial growth factor (VEGF)-induced endothelin-1 production in human umbilical vein endothelial cells (HUVECs). METHODS: Endothelin-1 levels were measured in conditioned medium of women with preeclampsia HUVECs were treated with different concentrations of VEGF(165) and at various time intervals. Next, we measured endothelin-1 levels after HUVECs were also incubated with VEGF and endothelin-converting enzyme-1 (ECE-1) inhibitor or tissue inhibitors of matrix metalloproteinase-2 (TIMP-2). Additionally, the circulating levels of total and free VEGF, matrix metalloproteinase-2 (MMP-2), and endothelin-1 were measured in 20 preeclamptic patients and 20 healthy pregnant controls. RESULTS: HUVECs treated with VEGF increased their endothelin-1 production in a concentration and time-dependent manner. The production of endothelin-1 was inhibited by TIMP-2, but not by the ECE-1 inhibitor. Total VEGF, MMP-2, and endothelin-1 concentrations were higher in preeclampsia and showed significant positive correlations between them. CONCLUSION: These findings suggest that VEGF-induced endothelin-1 production might be mediated by MMP-2 rather than by ECE-1 upregulation.
