ABSTRACT
In this study, we evaluated 62 sow sera samples from PED-vaccinated sows to compare the serum neutralizing test (SNT) and enzyme-linked immunosorbent assay (ELISA). We performed protein ELISA (pELISA) using fragments of spike proteins S1, S2, S3 and entire nucleocapsid proteins, and found a correlation between the SNT and ELISA in PEDV-vaccinated sera. Sera with higher neutralizing activity showed higher titers of IgG. In the antibody profiling, the neutralizing activities are correlated with the levels of the spike antibody, especially the S3 region. We confirmed that the carboxy-terminal region, including the endodomain of the S protein, induced stronger neutralizing activity than the ectodomain. This region of the S protein could be useful for evaluating PED vaccine efficacy, and it is a strong neutralizing epitope of PEDV. The S3 protein could be useful for evaluating PED vaccine efficacy, and it is a strong neutralizing epitope of PEDV.
ABSTRACT
To identify potent antiviral compounds, we introduced a high-throughput screen platform that can rapidly classify hit compounds according to their target. In our platform, we performed a compound screen using a lentivirus-based pseudovirus presenting a spike protein of coronavirus, and we evaluated the hit compounds using an amplified luminescence proximity homogeneous assay (alpha) test with purified host receptor protein and the receptor binding domain of the viral spike. With our screen platform, we were able to identify both spike-specific compounds (class I) and broad-spectrum antiviral compounds (class II). Among the hit compounds, thiosemicarbazide was identified to be selective to the interaction between the viral spike and its host cell receptor, and we further optimized the binding potency of thiosemicarbazide through modification of the pyridine group. Among the class II compounds, we found raloxifene and amiodarone to be highly potent against human coronaviruses including Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus (SARS-CoV), and SARS-CoV-2. In particular, using analogs of the benzothiophene moiety, which is also present in raloxifene, we have identified benzothiophene as a novel structural scaffold for broad-spectrum antivirals. This work highlights the strong utility of our screen platform using a pseudovirus assay and an alpha test for rapid identification of potential antiviral compounds and their mechanism of action, which can lead to the accelerated development of therapeutics against newly emerging viral infections.
ABSTRACT
PURPOSE: Coronavirus disease 2019 (COVID-19) has emerged as a serious threat to public health; anticancer-repositioning treatment strategy has been formulated to treat the disease. However, evidence supporting the efficacy and safety of repositioned anticancer treatment in treating COVID-19-infected non-cancer patients (CINPs) is limited. Therefore, this study analyzed published randomized controlled trials (RCTs) evaluating the impact of anticancer drugs compared to current standards of care (SOCs) on CINP treatment. MATERIALS AND METHODS: The PubMed and Embase databases were searched to identify eligible RCTs. Outcome measures included mortality, the use of mechanical ventilation (MV), and serious adverse events (SAEs). RESULTS: 25 RCTs were reviewed in our study. Compared to SOCs, repositioned anticancer therapy for treating CINPs was associated with mortality reduction (odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.65 - 0.94, p = 0.01). Using the repositioned anticancer treatment exhibited statistically significant reduction, in both the number of CINPs using MV (OR = 0.67, 95% CI = 0.51 - 0.88, p = 0.004) and experiencing SAEs (OR = 0.79, 95% CI = 0.69 - 0.91, p = 0.0009). CONCLUSION: Conclusively, repositioned anticancer treatment was shown significant differences from SOCs in treating CINPs, which appears to be more associated with mortality, MV use, and SAE development reduction in CINPs.