Project description:Mucin hypersecretion, a hallmark of chronic respiratory diseases (CRD), creates a complex microenvironment that reshapes host immunity and microbial behavior. However, its impact on bacteriophage therapy remains poorly understood. Here, we demonstrate that, despite reducing Pseudomonas aeruginosa internalization, mucin increases bacterial-induced cytotoxicity and inflammation in airway epithelial cells, while driving CRD-like transcriptional changes, including hypoxia and stress responses. Mucin selectively downregulates virulence factors without impairing bacterial growth. P. aeruginosa-infecting bacteriophage DMS3vir retained full lytic activity in mucin-rich conditions and, in synergy with mucin, enhanced epithelial cells protection against cytotoxicity. DMS3vir also reduced IL-8 gene expression without triggering antiviral responses. Furthermore, mucin shaped phage-resistant P. aeruginosa phenotypes, altering pigmentation, pigmentation, pyocyanin production, and motility. These changes influenced virulence trade-offs. These findings uncover the dual role of mucins as modulators of infection and sensitizers to phage protection, paving the way for optimized, mucosa-adapted phage therapies in chronic lung diseases.
Project description:As a human tumor virus, EBV is present as a latent infection in its associated malignancies where genetic and epigenetic changes have been shown to impede cellular differentiation and viral reactivation. One such change is increased levels of the Wnt signaling effector, lymphoid enhancer binding factor 1 (LEF1) following EBV epithelial infection. In silico analysis of EBV type 1 and 2 genomes identified over 20 Wnt-response elements suggesting that LEF1 may directly bind the EBV genome and regulate the viral life cycle. Using CUT&RUN-seq, LEF1 was shown to bind the latent EBV genome at various sites encoding viral lytic products that included the immediate early transactivator BZLF1 and viral primase BSLF1 genes. SiRNA depletion of specific LEF1 isoforms revealed that the alternative-promoter derived isoform with an N-terminal truncation (∆N LEF1) transcriptionally repressed lytic genes associated with LEF1 binding. Furthermore, forced expression of the ∆N LEF1 isoform antagonized EBV reactivation from latency. The LEF1 mediated repression requires histone deacetylase activity through either recruitment or a direct intrinsic histone deacetylase activity. SiRNA depletion of LEF1 resulted in increased histone 3 lysine 9 and lysine 27 acetylation at LEF1 binding sites and across the EBV genome. These results support a novel role for LEF1 in maintaining EBV latency and restriction viral reactivation via repressive chromatin remodeling of critical lytic cycle factors