January 10, 2019 (ScienceDaily)
A new study, carried out by researchers from the National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN) and Osaka University, has found that a peptide, called neuropeptide Y (NPY), which is typically located in the nervous system, has a critical role in intensifying pulmonary inflammation and viral replication in severe influenza virus infection.
After studying NPY and its receptor, Y1Rs’ impact in mice with influenza, the researchers have concluded that the NPY produced in lung phagocytes can aggravate influenza. It does so by impairing anti-viral response and encouraging pro-inflammatory cytokine production.
This work is now published in Nature Microbiology.
The researchers extracted immune cells from the lungs of infected mice and used immunofluorescence, flow cytometry, next-generation sequencers and bioinformatic analysis to examine their function. In addition, the researchers studied gene expression and protein levels – key ones that were either activated or deactivated. They then compared their levels to the severity of disease which was present in the lungs.
“The NPY and Y1 receptor axis on lung phagocytes is activated in severe influenza and this leads to a more serious infection and poorer outcomes,” says first author Seiki Fujiwara.
With this information, deleting NPY led to improved outcomes in the infected mice in terms of disease pathology and severity of influenza.
This fascinating work highlights the role lung phagocytes exhibit in determining not only the extent of immune response to influenza, but also, if targeting these phagocytes could lead to a process for diagnosing and mitigating influenza severity.