ABSTRACT

Interleukin 4 (IL-4) was identified in 1982 for its ability to induce the proliferation of murine B lymphocytes costimulated with anti-IgM [1] and for its capacity to induce lipopolysaccharide (LPS) activated B cells to produce IgG1 [2]. In 1986, a cDNA encoding human IL-4 was isolated [3], while in 1993 human IL-13 was isolated from T cell clones and activated T lymphocytes [4,5]. IL-4 and IL-13 belong to the cytokine superfamily including IL-3, IL-5 and granulocyte-macrophage colony stimulating factor (GM-CSF).