ABSTRACT
Spike protein of SARS-CoV-2 variants play critical role in the infection and transmission through its interaction with hACE2 receptor. Prior findings using molecular docking and biomolecular studies reported varied findings on the difference in the interactions among the spike variants with hACE2 receptor. Hence, it is a prerequisite to understand these interactions in a more precise manner. To this end, firstly, we performed ELISA with trimeric spike proteins of Wild (Wuhan Hu-1), Delta, C.1.2 and Omicron variants. Further, to study the interactions in a more specific manner by mimicking the natural infection, we developed hACE2 receptor expressing HEK-293T cell line and evaluated binding efficiencies of the variants and competitive binding of spike variants with D614G spike pseudotyped virus. In lines with the existing findings, we observed that Omicron had higher binding efficiency compared to Delta in both ELISA and Cellular models. Intriguingly, we found that cellular models could differentiate the subtle differences between the closely related C.1.2 and Delta in their binding to hACE2. From the analysis in receptor binding domain (RBD) revealed that a single common modification, N501Y, present in both Omicron and C.1.2 is driving the enhanced spike binding to the receptor and showed two-fold superior competitive binding than Delta. Our study using cellular model provides a precise method to evaluate the binding interactions between spike sub-lineages to hACE2 receptors and signifies the role of single common modification N501Y in RBD towards imparting superior binding efficiencies. Our approach would be instrumental in understanding the disease progression and developing therapeutics. Author SummarySpike proteins of evolving SARS-CoV2 variants demonstrated their signature binding to hACE2 receptor, in turn contributed to driving the infection and transmission. Prior studies to scale the binding efficiencies between the spike variant and the receptor had consensus in distinct variants, but discrepancies in the closely related ones. To this end, we compared spike variants-receptor interactions with ELISA, from cells expressing hACE2 receptor. Intriguingly, we found that cellular models could differentiate the subtle differences between the closely related C.1.2 and Delta in their binding to hACE2. More importantly, competitive binding studies in presence of pseudovirus, demonstrated that a single common modification, N501Y, present in both Omicron and C.1.2 showed two fold superior competitive binding than Delta. Collectively, our study suggests a precise approach to evaluate the binding interactions between spike sub-lineages to hACE2 receptor. This would be instrumental in understanding the disease progression and developing therapeutics.
ABSTRACT
ObjectivesTo compare the co-administration of an Ayurvedic drug AYUSH 64 as an adjunct to standard of care (SOC) and SOC for efficacy and safety in the management of COVID-19. DesignMulticentre, parallel efficacy, randomized, controlled, open label, assessor blind, exploratory trial with a convenience sample. Patients followed to complete 12 weeks of study duration. SettingCOVID-19 dedicated non-intensive care wards at 1 government hospital, 1 medical college teaching hospital and 1 medical university teaching hospital Participants140 consenting, eligible, hospitalized adult patients suffering from mild and moderate symptomatic COVID-19 and confirmed by a diagnostic (SARS-CoV-2) RT-PCR assay on nasal and throat swab were randomized to SOC or SOC plus AYUSH 64. To be withdrawn if disease becomes severe. InterventionsTwo tablets of AYUSH 64, 500 mg each, twice daily after meals, and continued till study completion. SOC (symptomatic and supportive) as per national guidelines of India for mild and moderate disease. Main outcome measuresTime period to clinical recovery (CR) from randomization baseline and proportion with CR within 28 days time frame; CR defined in the protocol Results140 patients randomized (70 in each arm); 138 patients with CR qualified for analysis. Both groups were matched at baseline. The mean time to CR from randomization was significantly superior in AYUSH 64 group (95% CI -3.03 to 0.59 days); a higher proportion (69.7%) in the first week (p=0.046, Chi-square). No significant differences observed for COVID-19 related blood assays (such as D-Dimer). AYUSH 64 arm showed significant (p<0.05) superior persistent improvement in general health, quality of life, fatigue, anxiety, stress, sleep and other psychosocial metrics. 1 patient on SOC required critical care. 48 adverse events (AE) reported in each group. Barring three SAE (in SOC), AE were mild and none were drug related. 22 participants (8 on AYUSH) were withdrawn. No deaths were reported. ConclusionsAYUSH 64 hastened recovery, reduced hospitalization and improved overall health in mild and moderate COVID-19 when co-administered with SOC under medical supervision. It was safe and well tolerated. Further studies are warranted. Trial registrationThe Clinical Trials Registry India Number CTRI/2020/06/025557 FundingCCRAS, Ministry of AYUSH, Government of India
ABSTRACT
Methods@#A total of 18 mice were divided into injured (n=12) and non-injured (n=6) groups. The disc height index (DHI%) at coccygeal 4–5 level was measured by computed tomography (CT) scan for all mice. Coccygeal 4–5 discs of the injury group were injured using a 32G needle fixed to a novel tool and confirmed by CT. The non-injury group underwent no procedure. DHI% was measured by CT at 2-, 4-, and 6-week post-injury, and all mice tails were sectioned for histopathology grading of disc degeneration at the respective time intervals. @*Results@#The injured group showed significant variation in DHI% at 2, 4, and 6 weeks, whereas there was no change in the noninjured group. Histopathologic evaluation with Safranin O stain showed a worsening of the disc degeneration score at 2, 4, and 6 weeks in the injured group, but in the non-injured group there was no change. Percutaneous needle injury technique with our novel tool provided 100% accuracy and uniform degeneration. @*Conclusions@#A simple, easily reproducible mouse model for disc degeneration was created using a simple, cost-effective, novel tool and technique, its advantage being high precision and user friendly.
ABSTRACT
Methods@#A total of 18 mice were divided into injured (n=12) and non-injured (n=6) groups. The disc height index (DHI%) at coccygeal 4–5 level was measured by computed tomography (CT) scan for all mice. Coccygeal 4–5 discs of the injury group were injured using a 32G needle fixed to a novel tool and confirmed by CT. The non-injury group underwent no procedure. DHI% was measured by CT at 2-, 4-, and 6-week post-injury, and all mice tails were sectioned for histopathology grading of disc degeneration at the respective time intervals. @*Results@#The injured group showed significant variation in DHI% at 2, 4, and 6 weeks, whereas there was no change in the noninjured group. Histopathologic evaluation with Safranin O stain showed a worsening of the disc degeneration score at 2, 4, and 6 weeks in the injured group, but in the non-injured group there was no change. Percutaneous needle injury technique with our novel tool provided 100% accuracy and uniform degeneration. @*Conclusions@#A simple, easily reproducible mouse model for disc degeneration was created using a simple, cost-effective, novel tool and technique, its advantage being high precision and user friendly.
