Speaker
Description
Influenza A virus (IAV) infection leads to pathogenetically important metabolic changes in host cells, but a comprehensive functional analysis of substrate utilization in IAV-infected cells has not been performed. We adapted the Phenotype MicroArrayTM for mammalian cells system to study changes in host cell respiration during IAV infection, based on simultaneous analysis of metabolism on 367 energy substrates in real time. Basal cell respiration increased upon infection of A549 cells with two different H1N1 isolates. In infected cells, respiration was lower on polysaccharides but higher on polyols as substrates, most significantly when mannitol was offered as carbon source. Remarkably, adding mannitol to cells growing in medium with or without glucose significantly increased replication of both strains. Metabolic flux analyses with C13-labeled mannitol revealed that infected cells, but not uninfected cells, acquired the ability to take up mannitol and use it as a carbon source for glycolysis, Krebs cycle intermediates, and amino acid synthesis. Remarkably, when cells were grown in the presence of both glucose and mannitol, nearly all lactate was derived from mannitol once glucose was depleted. Microarray analysis revealed that mannitol led to a significant reduction of the expression of mRNAs encoding the key enzymes of the polyol pathway, i.e. sorbitol dehydrogenase and aldo-keto reductase. These results provide the, to our knowledge, first evidence that higher eukaryotic cells can use extracellular mannitol as a carbon source and suggest that this pathway (1) is highly inducible by IAV and (2) may depend on enzymes distinct from the classical polyol pathway.
| Choose secondary Session | Pathogenesis |
|---|---|
| Choose primary session | Virus host cell interaction |
