Dengue, West Nile, Zika, Yellow fever, and Japanese encephalitis viruses persist as significant global health threats. The development of new therapeutic strategies based on inhibiting essential viral enzymes or viral–host protein interactions is problematic due to the fast mutation rate and rapid emergence of drug resistance. This study focuses on the NS2B-NS3 protease as a promising target for antiviral drug development. Promising allosteric binding sites were identified in two conformationally distinct inactive states and characterized for five flaviviruses and four Dengue virus subtypes. Their shapes, druggability, inter-viral similarity, sequence variation, and susceptibility to drug-resistant mutations have been studied. Two identified allosteric inactive state pockets appear to be feasible alternatives to a larger closed pocket near the active site, and they can be targeted with specific drug-like small-molecule inhibitors. Virus-specific sequence and structure implications and the feasibility of multi-viral inhibitors are discussed.

Therapeutic antibodies designed to target three immune checkpoint proteins have been applied in the treatment of various malignancies, including small and non-small cell lung cancers, melanoma, renal cell carcinoma, and others. These treatments combat cancers by reactivating cytotoxic T cells. Nevertheless, this mode of action was found to be associated with a broad range of immune-related adverse events (irAEs), including pneumonitis, sarcoidosis, myocarditis, nephritis, colitis, and hepatitis. Depending on their severity, these irAEs often necessitate the suspension or discontinuation of treatment and, in rare instances, may lead to fatalities. We analyzed over nineteen million reports and identified over eighty thousand adverse event reports from patients treated with immune checkpoint inhibitors submitted to the Food and Drug Administration’s Adverse Event Reporting System MedWatch. Reports concerning pembrolizumab, nivolumab, cemiplimab, avelumab, durvalumab, atezolizumab, and ipilimumab revealed a statistically significant association between the irAEs and concurrent infectious diseases for five out of seven treatments. Furthermore, the association trend was preserved across all three types of checkpoint inhibitors and each of the five individual therapeutic agent cohorts, while the remaining two showed the same trend, but an increased confidence interval, due to an insufficient number of records.

Immune checkpoint inhibitors (ICIs), including anti-PD-1, PD-L1, and CTLA-4 antibodies, have advanced cancer therapy but are often associated with serious immune-related adverse events (irAEs). Analysis of over 80,000 monotherapy reports from the FDA Adverse Event Reporting System revealed that co-occurring infections significantly increase irAE risk - including events such as sarcoidosis, pneumonitis, colitis, hepatitis, myocarditis, and nephritis. The presented work and our initial findings [1] highlights the critical need for improved therapeutic strategies. To overcome the limitations of antibody-based ICIs - such as therapeutic efficacy, high cost, limited tissue penetration, and immunogenicity and engage new mechanism of PD-L1 internalization - we performed an in silico screening to identify small-molecule PD-L1 “glue” like modulators. We used ICM-Pro software with GPU acceleration to screen 1.5 million compounds from the ChemBridge library. After that, we filtered the results based on their chemical properties. Next, we selected 20,000 compounds and performed redocking. Finally, we refined the top 200 compounds for further analysis. Final candidates were selected for in vitro testing. Two lead compounds are currently under experimental evaluation and being compared with BMS-202, a known PD-L1 small molecule inhibitor. This combined clinical and computational approach supports the development of next-generation, low-toxicity immunotherapies.

Background/Objectives. Programmed death-ligand 1 (PD-L1) is a critical immune checkpoint protein that enables tumors to evade immune surveillance by suppressing T cell activation. Monoclonal antibodies are currently used to modulate PD-1/PD-L1 interactions. However, several immune-associated adverse effects were ascribed to those treatments. This led to the necessity for small-molecule alternatives like BMS-202. Methods. In this study, we investigated the temporal dynamics of cell-surface PD-L1 in response to the small-molecule dimerizer BMS-202. Treatment with a non-cytotoxic concentration of BMS-202 at 5 µM triggered a transient reduction in surface PD-L1 concentration, reaching its lowest level at 15 min. In the attempt to characterize the fate of PD-L1 following exposure to the BMS-202 dimerizer, we employed a low-pH wash internalization assay. Results. The results demonstrated a transient increase in intracellular PD-L1 within 5–15 min of compound exposure, followed by rapid recovery of surface PD-L1 levels. These findings suggest that BMS-202-induced changes in surface PD-L1 are acute and reversible, with levels returning to baseline within 24 h post-exposure. Conclusions. These findings reveal a dynamic regulatory mechanism where small-molecule-induced dimerization triggers rapid protein trafficking and transient surface depletion. Understanding these temporal dynamics is essential for the development of next-generation small-molecule immune checkpoint inhibitors.