Regulation of C-C chemokine receptor 5 (CCR5) stability by Lys197 and by transmembrane protein aptamers that target it for lysosomal degradation

Leveraging aptamers for targeted protein degradation

Targeted protein degradation (TPD) technologies, particularly proteolysis-targeting chimeras (PROTACs), have emerged as a significant advancement in drug discovery. However, several hurdles - such as the difficulty of identifying suitable ligands for traditionally undruggable proteins, poor solubility and impermeability, nonspecific biodistribution, and on-target off-tissue toxicity - present challenges to their clinical applications. Aptamers are promising ligands for broad-ranging molecular recognition. Utilizing aptamers in TPD has shown potential advantages in overcoming these challenges. Here, we provide an overview of recent developments in aptamer-based TPD, emphasizing their potential to achieve targeted delivery and their promise for the spatiotemporal degradation of undruggable proteins. We also discuss the challenges and future directions of aptamer-based TPD with the goal of facilitating their clinical applications.

Traptamer screening: a new functional genomics approach to study virus entry and other cellular processes

Historically, the genetic analysis of mammalian cells entailed the isolation of randomly arising mutant cell lines with altered properties, followed by laborious genetic mapping experiments to identify the mutant gene responsible for the phenotype. In recent years, somatic cell genetics has been revolutionized by functional genomics screens, in which expression of every protein-coding gene is systematically perturbed, and the phenotype of the perturbed cells is determined. We outline here a novel functional genomics screening strategy that differs fundamentally from commonly used approaches. In this strategy, we express libraries of artificial transmembrane proteins named traptamers and select rare cells with the desired phenotype because, by chance, a traptamer specifically perturbs the expression or activity of a target protein. Active traptamers are then recovered from the selected cells and can be used as tools to dissect the biological process under study. We also briefly describe how we have used this new strategy to provide insights into the complex process by which human papillomaviruses enter cells.

Considering Interim Interventions to Control COVID-19 Associated Morbidity and Mortality-Perspectives

Aims and objectives: The pandemic of COVID-19 is evolving worldwide, and it is associated with high mortality and morbidity. There is a growing need to discuss the elements of a coordinated strategy to control the spread and mitigate the severity of COVID-19. H1N1 and Streptococcus pneumonia vaccines are available. The current analysis was performed to analyze the severity of COVID-19 and influenza (H1N1) vaccination in adults ≥ 65. Also, to correlate the lower respiratory tract infections (LRIs), and influenza attributable to the lower respiratory tract infections' incidence with Covid-19 mortality. Evolutionarily influenza is close in resemblance to SARS-CoV-2 viruses and shares some common epitopes and mechanisms.

Methods: Recent influenza vaccination data of 34 countries from OECD and other publications were correlated with COVID-19 mortality from worldometer data. LRIs attributable to influenza and streptococcus pneumonia were correlated with COVID-19 mortality. Specifically, influenza-attributable LRI incidence data of various countries (n = 182) was correlated with COVID-19 death by linear regression and receiver operating characteristic (ROC) curve analyzes. In a logistic regression model, population density and influenza LRI incidence were correlated with COVID-19 mortality.

Results: There is a correlation between COVID-19-related mortality, morbidity, and case incidence and the status of influenza vaccination, which appears protective. The tendency of correlation is increasingly highlighted as the pandemic is evolving. In countries where influenza immunization is less common, there is a correlation between LRIs and influenza attributable to LRI incidence and COVID-19 severity, which is beneficial. ROC curve showed an area under the curve of 0.86 (CI 0.78 to 0.944, P < 0.0001) to predict COVID-19 mortality >150/million and a decreasing trend of influenza LRI episodes. To predict COVID-19 mortality of >200/million population, the odds ratio for influenza incidence/100,000 was −1.86 (CI −2.75 to −0.96, P < 0.0001). To predict the parameter Covid-19 mortality/influenza LRI episodes^*1000>1000, the influenza parameter had an odd's ratio of −3.83 (CI −5.98 to −1.67), and an AUC of 0.94.

Conclusion: Influenza (H1N1) vaccination can be used as an interim measure to mitigate the severity of COVID-19 in the general population. In appropriate high-risk circumstances, Streptococcus pneumonia vaccination would also be an adjunct strategy, especially in countries with a lower incidence of LRIs.