Cutting Edge: Cd49d(+) Neutrophils Induce Fc Epsilon Ri Expression On Lung Dendritic Cells In A Mouse Model Of Postviral Asthma

The increasing prevalence of atopy and asthma remains unexplained but may be due to infection with respiratory viruses. In support of this hypothesis, we showed that experimental asthma after viral infection in mice depended on type I IFN-driven upregulation of Fc epsilon RI on conventional dendritic cells (cDCs) in the lung. In this article, we demonstrate that Fc epsilon RI expression on lung cDCs depends on an unexpected activity of a CD49d(+) subset of polymorphonuclear neutrophils (PMNs) that are found in the lungs of wild-type C57BL6 but not mice deficient in type I IFNR. Expression of Fc epsilon RI depends in part on a CD11b-dependent interaction between PMNs and cDCs. This study demonstrates a PMN-cDC interaction in the lung that is necessary for the ability of viral infection to induce atopic disease. The Journal of Immunology, 2010, 185: 4983-4987.