bioRxiv Science⌕ Search

bioRxiv · 10.1101/2025.10.14.682270

NAD metabolism plays multiple roles in influenza A virus replication in a novel ex vivo model of mouse lung infection.

Abstract

Despite the availability of prophylactic and therapeutic measures, Influenza A viruses (IAV) remain a major public health concern, causing an estimated 650 000 deaths annually. In this context, the identification of metabolic vulnerabilities of IAV replication could help develop complements to existing antiviral strategies. Here, we used nicotinamide phosphoribosyltransferase (NAMPT) inhibitors to demonstrate that nicotinamide adenine dinucleotide (NAD) is essential for IAV replication and infectious particles production both in vitro and ex vivo. We established an innovant ex vivo model of murine organotypic lung cultures (mOLC) that is pertinent to analyze cell metabolic alterations triggered by IAV infection. Using untargeted metabolomic profiling and spatial transcriptomic analyses, our research revealed that IAV-infection decreased NAD+ levels in mOLCs, while PARPs, a group of NAD+-consuming enzymes, were upregulated. Pharmacological inhibition of the mono-ADP-ribosyl-transferase (mono-ART) activity of PARPs restricted IAV infection ex vivo, suggesting that NAD+ sustains the proviral activity of these enzymes. Overall, our study identifies NAD metabolism as a central regulator of IAV infection, providing redox cofactor to host cell biosynthetic processes and substrate for mono-ART activity. Our results highlight NAMPT and PARP mono-ART activity as promising antiviral targets. Significance StatementViruses are intracellular parasites that rely on the host cellular metabolism for their replication. Our results demonstrate that Influenza A virus (IAV) replication is critically dependent on NAD availability, an enzyme cofactor essential for redox metabolic reactions and a substrate for NAD+-consuming enzymes. Using a novel ex vivo infection model of mouse lung tissue, we found that IAV infection results in NAD depletion and enhanced expression of NAD-consuming PARP enzymes. Inhibitors of NAD biosynthesis and mono(ADP-ribosyl) transferase activity of PARP are restricting viral replication and infectious particles production. These findings highlight the proviral role for PARP mono-ART activity and identify NAMPT and PARP inhibitors as potential host-directed antivirals against IAV.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jacolin, F., Aublin-Gex, A., Vellet, M., Decimo, D., Lepetit, M., Canus, L., OGIRE, E., Cezard, A., Jacquemin, C., Croze, S., Lachuer, J., Marcy, G., Diaz, O., LOTTEAU, V., Vidalain, P.-O., Si-Tahar, M., Mathieu, C., Perrin-Cocon, L.. 2025-10-14. NAD metabolism plays multiple roles in influenza A virus replication in a novel ex vivo model of mouse lung infection.. https://doi.org/10.1101/2025.10.14.682270

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A population-scale landscape of the subgingival microbiome reveals divergent routes to periodontal dysbiosis

Periodontitis is an archetypical mucosal inflammatory disease in which microbiome dysbiosis at the tooth-epithelial interface interacts with host genetic and behavioral risk factors to drive immune-mediated tissue destruction. Although subgingival microbiome compositional shifts are thought to parallel disease severity, microbiome variation at the population-level and its relationship to periodontal clinical phenotypes and disease-modifying factors remain poorly defined. Here, we use unsupervised manifold learning to map the compositional landscape of the subgingival microbiome in 1,355 adults spanning periodontal health to severe periodontitis. We identified eight latent microbiome states organized along a branching continuum from eubiosis to dysbiosis. An intermediate microbial configuration marked ecological destabilization and bifurcation into two distinct periodontitis-associated dysbiotic trajectories, distinguished by links to gingival inflammation and smoking. Although the microbiome trajectories broadly tracked periodontal destruction, a minority of individuals showed discordant microbiome-clinical phenotypes, with some individuals with periodontitis retaining otherwise eubiotic microbiomes enriched for low-abundance pathobionts, while some cases of health or mild disease had highly dysbiotic communities, suggesting distinct host susceptibility. Together, these findings define a population-scale ecological landscape of the subgingival microbiome, reveal divergent trajectories to periodontal dysbiosis, and highlight heterogeneity in the relationship between microbial community structure and clinical disease expression.

microbiology↗

The iron-binding siderophore enterobactin is required for the response of multi-drug resistant Klebsiella pneumoniae to zinc limitation

To persist during infection Klebsiella pneumoniae must overcome nutrient iron and zinc limitation imposed by the host immune system through a process called nutritional immunity. Secreted small molecule siderophores are a major virulence determinant of Klebsiella pneumoniae pathogenesis and are presumed to overcome nutritional immunity by binding iron for bacterial acquisition. In this work, we set out to identify how a multi-drug resistant K. pneumoniae grows in zinc limited environments. Using unbiased transcriptomics, proteomics, and an arrayed transposon screen, we identified that synthesis and uptake of the siderophore enterobactin is required to allow for growth in low zinc conditions. Iron-specific chelators did not replicate this phenotype and addition of supplemental iron through heme in growth media could not complement severe growth defects of enterobactin mutant K. pneumoniae experiencing zinc limitation. Finally, zinc starvation induced enterobactin production independent of the canonical zinc uptake regulator (Zur) transcription factor suggesting an unidentified regulatory mechanism by which Gram-negative pathogens may respond to zinc stress. Together, these studies expand the role of enterobactin beyond iron regulation and highlight a previously unreported link between iron and zinc homeostasis in Klebsiella pneumoniae.

microbiology↗

A microbiota-derived protease links phage susceptibility to host epithelial responses

Bacteriophages are major ecological drivers of gut microbial ecology, yet whether bacterial mechanisms that determine phage susceptibility have consequences for the mammalian host remains poorly understood. Here, we identify dipeptidyl peptidase 11 (Dpp11a), the predominant active serine protease of the prevalent gut commensal Phocaeicola vulgatus, as an unexpected bacterial defence factor. Dpp11a protects against environmental proteases and confers resistance to bacteriophage infection. Metatranscriptomic analyses further reveal increased expression of both dpp11a and P. vulgatus-associated phage transcripts in ulcerative colitis stool samples, indicating that both components of this interaction are transcriptionally active in disease-associated human microbiomes. Using the microfluidic gut-on-a-chip co-culture model HuMiX, we show that the absence of Dpp11 is accompanied by altered epithelial tight-junction remodelling during phage-bacterial infection. Together, our findings reveal that the consequences of bacterial phage defence can extend beyond phage-bacterium interactions to the mammalian epithelium.

microbiology↗