Iron Overload Is Associated With Oxidative Stress and Nutritional Immunity During Viral Infection in Fish

Iron is a trace element, essential to support life due to its inherent ability to exchange electrons with a variety of molecules. The use of iron as a cofactor in basic metabolic pathways is essential to both pathogenic microorganisms and their hosts. During evolution, the shared requirement of micro- and macro-organisms for this important nutrient has shaped the pathogen–host relationship. Infectious pancreatic necrosis virus (IPNv) affects salmonids constituting a sanitary problem for this industry as it has an important impact on post-smolt survival. While immune modulation induced by IPNv infection has been widely characterized on Salmo salar , viral impact on iron host metabolism has not yet been elucidated. In the present work, we evaluate short-term effect of IPNv on several infected tissues from Salmo salar . We observed that IPNv displayed high tropism to headkidney, which directly correlates with a rise in oxidative stress and antiviral responses. Transcriptional profiling on headkidney showed a massive modulation of gene expression, from which biological pathways involved with iron metabolism were remarkable. Our findings suggest that IPNv infection increase oxidative stress on headkidney as a consequence of iron overload induced by a massive upregulation of genes involved in iron metabolism.