[Interleukin-4: from B-lymphocyte to fibroblast].

Interleukin-4 (IL-4) has been characterized in 1982 by its ability to induce the proliferation of anti-IgM stimulated B-lymphocytes and IgG1 secretion by these same cells after activation by lipopolysaccharide. It's activity on B-cells explain that it received the former names of B-Cell Growth Factor-1 (BCGF-1) or B-Cell Stimulatory Factor-1 (BSF-1). More recent works have shown that IL-4 exerts pleiotropic effects on a large number of cells. Particularly, it is able to activate the production of extracellular matrix components by fibroblasts. The aim of the present paper is to review main data about this cytokine, with a particular emphasis on its role on the regulation of connective tissue cell activities and on its possible implication in pathophysiological events such as fibrosis, wound healing, and tumor invasion.