T-Cell-Dependent Accumulation of Eosinophils in the Lung and Its Inhibition by Monoclonal Anti-Interleukin-5

Abstract

The transnasal administration of an extract of the parasite Ascaris suum to C57BL/6 mice for 3 weeks produced marked eosinophilia in the bronchoalveolar lavage (BAL) fluid. The oral administration of ciclosporin significantly suppressed the pulmonary eosinophilia. Athymic C57BL/6-nu/nu mice failed to develop pulmonary eosinophilia. These data indicate that the pulmonary eosinophilia caused by this parasite extract is T-cell-dependent. Genetically mast-cell-deficient (WB x C57BL/6) F1-W/Wv (W/Wv) mice developed marked eosinophilia in the BAL, which shows that mast cells are not necessary in the formation of lung eosinophilia in this model. Monoclonal antimurine interleukin-5 injected intraperitoneally clearly inhibited the infiltration of eosinophils in the lung, suggesting that T-cell-derived interleukin-5 is essential.