In Vitro Analysis of SARS-CoV-2 Spike Protein and Ivermectin Interaction.

The spike (S) protein of SARS-CoV-2 is a molecular target of great interest for developing drug therapies against COVID-19 because S is responsible for the interaction of the virus with the host cell receptor. Currently, there is no outpatient safety treatment for COVID-19 disease. Furthermore, we consider it of worthy importance to evaluate experimentally the possible interaction of drugs (approved by the Food and Drug Administration) and the S, considering some previously in silico and clinical use. Then, the objective of this study was to demonstrate the in vitro interaction of ivermectin with S. The equilibrium dialysis technique with UV-Vis was performed to obtain the affinity and dissociation constants. In addition, the Drug Affinity Responsive Target Stability (DARTS) technique was used to demonstrate the in vitro interaction of S with ivermectin. The results indicate the interaction between ivermectin and the S with an association and dissociation constant of Ka = 1.22 µM-1 and Kd = 0.81 µM, respectively. The interaction was demonstrated in ratios of 1:50 pmol and 1:100 pmol (S: ivermectin) by the DARTS technique. The results obtained with these two different techniques demonstrate an interaction between S and ivermectin previously explored in silico, suggesting its clinical uses to stop the viral spread among susceptible human hosts.

Immunothrombosis in COVID-19: Implications of Neutrophil Extracellular Traps.

SARS-CoV-2 is a member of the family of coronaviruses associated with severe outbreaks of respiratory diseases in recent decades and is the causative agent of the COVID-19 pandemic. The recognition by and activation of the innate immune response recruits neutrophils, which, through their different mechanisms of action, form extracellular neutrophil traps, playing a role in infection control and trapping viral, bacterial, and fungal etiological agents. However, in patients with COVID-19, activation at the vascular level, combined with other cells and inflammatory mediators, leads to thrombotic events and disseminated intravascular coagulation, thus leading to a series of clinical manifestations in cerebrovascular, cardiac, pulmonary, and kidney disease while promoting severe disease and mortality. Previous studies of hospitalized patients with COVID-19 have shown that elevated levels of markers specific for NETs, such as free DNA, MPO, and H3Cit, are strongly associated with the total neutrophil count; with acute phase reactants that include CRP, D-dimer, lactate dehydrogenase, and interleukin secretion; and with an increased risk of severe COVID-19. This study analyzed the interactions between NETs and the activation pathways involved in immunothrombotic processes in patients with COVID-19.