P-688. PFKFB3-driven Glycolysis Controls Influenza A Virus Entry

Abstract Background Novel therapeutic intervention in acute respiratory virus infections remains a critical challenge due to high viral burden and severe inflammation. Glucose metabolism is a central driver of viral replication and host immune responses. The host enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) regulates glycolytic flux and may represent a metabolic checkpoint during infection. Methods Using influenza A H1N1 virus, we employed viral-host interaction assays, and real-time glycolysis monitoring (extracellular acidification rate analysis) to evaluate virus-induced metabolic reprogramming. Antiviral assays targeting PFKFB3 were conducted using genetic editing and pharmacological inhibition in vitro. A conditional lung-specific knockout mouse model (C57BL/6JCya-Pfkfb3em1flox/Cya) was generated to examine in vivo relevance. Results PFKFB3 expression was significantly upregulated in H1N1-infected BEAS-2B cells. Among viral proteins screened, PB1, PB2, PA, NS, and NA enhanced basal glycolysis, with PB1 inducing a dose-dependent increase in ECAR. Confocal microscopy revealed robust PB1–PFKFB3 colocalization. PFKFB3 deletion or inhibition reduced viral replication in vitro and in the conditional knockout mouse model. Mechanistically, PFKFB3 activity promoted glycosylation of host viral entry receptors, facilitating viral entry. Conclusion PFKFB3 acts as a host-encoded proviral factor during influenza A infection by enhancing glycolysis and receptor glycosylation. Targeting PFKFB3 offers a promising antiviral strategy in both cellular and animal models. Disclosures All Authors: No reported disclosures