Measles Virus Reprograms CD4+ T-Cell Sphingolipid Metabolism
Researchers identified that measles virus infection alters sphingolipid and fatty acid metabolism in CD4+ T cells. Pharmacological inhibition of these metabolic pathways significantly impaired viral replication.
Measles virus (MV) infection primarily targets CD150-positive lymphocytes, leading to the depletion of infected memory cells and subsequent suppression of immune memory. This process increases susceptibility to secondary infections and severe complications. While lipids are known to be critical for viral life cycles, the specific lipid metabolic conditions facilitating MV replication in immune cells remain poorly understood.
In this study, researchers conducted a comprehensive lipidomic analysis of MV-infected primary CD4+ T cells. The investigation focused on identifying alterations in three major lipid classes: sphingolipids, triacylglycerols, and glycerophospholipids. This approach aimed to elucidate the metabolic mechanisms supporting viral replication within these specific immune cell populations.
The analysis revealed significant alterations in lipid profiles during infection. Specifically, MV infection increased the abundance of ceramides, dihydroceramides, and triacylglycerols, while significantly reducing the levels of glucosylceramides and glycerophospholipids. Pharmacological intervention in the pathways of de novo sphingolipid synthesis, triacylglycerol synthesis, and lipolysis significantly impaired measles virus replication in activated CD4+ CD150+ T cells.
Mechanistically, the authors demonstrate that MV glycoprotein-mediated membrane fusion requires glucosylceramide synthase (GCS) activity. This process is essential for viral entry and cell-to-cell spread. Furthermore, plasma membrane triacylglycerol content further promotes this fusion event. Collectively, these findings highlight the essential role of MV-modulated triacylglycerol and sphingolipid metabolism in viral entry, dissemination, and intracellular replication within CD4+ T cells.
These results suggest that targeting specific lipid metabolic pathways could potentially interfere with measles virus replication. However, further research is needed to fully understand the clinical implications of these findings. This study provides valuable insights into the molecular mechanisms underlying MV pathogenesis in immune cells.