Osteopontin (Opn) is important for T helper type 1 (TH1) immunity and autoimmunity. However, the role of this cytokine in TH2-mediated allergic disease as well as its effects on primary versus secondary antigenic encounters remain unclear. Here we demonstrate that OPN is expressed in the lungs of asthmatic individuals and that Opn-s, the secreted form of Opn, exerts opposing effects on mouse TH2 effector responses and subsequent allergic airway disease: pro-inflammatory at primary systemic sensitization, and anti-inflammatory during secondary pulmonary antigenic challenge. These effects of Opn-s are mainly mediated by the regulation of TH2-suppressing plasmacytoid dendritic cells (DCs) during primary sensitization and TH2-promoting conventional DCs during secondary antigenic challenge. Therapeutic administration of recombinant Opn during pulmonary secondary antigenic challenge decreased established TH2 responses and protected mice from allergic disease. These effects on TH2 allergic responses suggest that Opn-s is an important therapeutic target and provide new insight into its role in immunity.

doi.org/10.1038/nm1580, hdl.handle.net/1765/36656
Nature Medicine
Erasmus MC: University Medical Center Rotterdam

Xanthou, G., Alissafi, T., Semitekolou, M., Simoes, D., Economidou, E., Gaga, M., … Panoutsakopoulou, V. (2007). Osteopontin has a crucial role in allergic airway disease through regulation of dendritic cell subsets. Nature Medicine, 13(5), 570–578. doi:10.1038/nm1580