Interleukin-4 is required for the induction of lung Th2 mucosal immunity.

Abstract

Aerosol antigen challenge of ovalbumin-sensitized mice induced an eosinophilic airway inflammation that was dependent on interleukin (IL)-5 and CD4+, but not CD8+, T lymphocytes. The involvement of the Th2 phenotype of CD4+ T cells was supported by demonstrating that FACS-sorted purified lung T cells from sensitized, but not control, mice produced IL-4, IL-5, and IL-10 after activation of the CD3/TCR complex. To determine the role of IL-4 in this process, we used mice in which the gene for IL-4 was deleted by homologous recombination. Antigen challenge of IL-4 gene-targeted mice resulted in a marked attenuation of eosinophilic inflammation and IL-5 secretion. To more fully understand the tim..