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

## TL;DR

This study shows that the enzyme PFKFB3 boosts influenza A virus entry by increasing glycolysis and receptor glycosylation, suggesting it as a potential antiviral target.

## Contribution

The study identifies PFKFB3 as a host factor that promotes influenza A virus entry through glycolysis and receptor glycosylation.

## Key findings

- PFKFB3 expression is upregulated in H1N1-infected cells and promotes viral replication.
- PFKFB3 deletion or inhibition reduces viral replication in vitro and in a mouse model.
- PFKFB3 enhances glycosylation of host viral entry receptors, facilitating viral entry.

## Abstract

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.

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.

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.

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.

All Authors: No reported disclosures