Children and adults living with obesity have more severe influenza A virus (IAV) infection, but the underlying mechanisms are unclear. Natural killer (NK) cells play a key role in the innate immune responses to IAV and clearance of IAV-infected cells. ‘Trained immunity’ of NK cells (and other innate immune cells) refers to an initial stimulus (i.e. obesity) inducing metabolic and epigenetic changes that make these cells hyperinflammatory upon restimulation (i.e. with IAV). Here, we tested whether obesity in children induces trained immunity in NK cells. We have show that NK cells from children with obesity have a hyperinflammatory ‘trained’ phenotype, with increased expression of activation markers TLR2, CCR2, TLR4, HLA-DR and CD11b compared to children without obesity. Furthermore, we have demonstrate that NK cells from children with obesity have a heightened ex vivo IFN-γ response to stimulation with IAV (A/Auckland/4/2009, H1N1 and HKx31, H3N2) and epigenetic changes consistent trained immunity. A decrease in BMI z-score following weight-management was not associated with a reduction in the IFN-γ response, suggesting that weight loss is not sufficient to normalise NK cell function. Better understanding of obesity-related immune modulation is critical for development of new therapeutic strategies and improving outcomes in future IAV pandemics
Ellesandra C. Noye, Megan Airey, Danielle K. Longmore, Hui Xu, David Chisanga, Christoph Saner, Meagan Carney, Meg Kaegi, Hiu On Man, M. Zeeshan Chaudhry, Liam C. Kealy, Julian D. J. Sng, Isabelle Hocking, Melanie Wu, Georgina McCallum, Gabrielle T. Belz, Kim L. Good-Jacobson, David Burgner, Siroon Bekkering, Kirsty Short
This file is in Adobe Acrobat (PDF) format. If you have not installed and configured the Adobe Acrobat Reader on your system.
PDFs are designed to be printed out and read, but if you prefer to read them online, you may find it easier if you increase the view size to 125%.
Many versions of the free Acrobat Reader do not allow Save. You must instead save the PDF from the JCI Online page you downloaded it from. PC users: Right-click on the Download link and choose the option that says something like "Save Link As...". Mac users should hold the mouse button down on the link to get these same options.