IL-4 is a cytokine which can be expressed by a number of cell types including T(h)2 cells, mast cells and a population of CD4+ NK1.1+ NK T cells. Although phenotypic markers exist for identifying each of these cell types, there is at present no known cell surface marker common to all IL-4-producing cells. Using gene targeting in embryonic stem cells, we have modified the IL-4 locus by knock-in of a transmembrane domain to generate mice that express a membrane-bound form of IL-4 (mIL-4). Flow cytometry using an IL-4-specific mAb allowed the detection of IL-4-secreting T(h)2 cells, mast cells and NK T cells from mIL-4 mice. Furthermore, the analysis of immune responses in mIL-4 mice following immunization with anti-CD3 and anti-lgD has allowed us to identify distinct subpopulations of IL-4-producing NK T cells. Thus, the expression of IL-4 in a membrane-bound form provides a novel method for the identification and characterization of IL-4-producing cells.
ASJC Scopus subject areas
- Immunology and Allergy