NOVEL BIOLOGICAL FUNCTIONS OF INTERLEUKIN-4 - FORMATION OF TUBE-LIKE STRUCTURES BY VASCULAR ENDOTHELIAL-CELLS IN-VITRO AND ANGIOGENESIS IN-VIVO

The effect of interleukin-4 (IL-4) on angiogenesis was studied in vitr o and in vivo. Human recombinant IL-4 significantly stimulated the for mation of tube-like structures in collagen gels by bovine aortic endot helial cells as well as by human microvascular endothelial cells. Huma n recombinant IL-4 at 50-500 U/ml stimulated by about two- to threefol d the formation of tubes by bovine aortic endothelial cells; the rate was comparable to that of basic fibroblast growth factor. Tube formati on was almost completely inhibited by the addition of IL-4 receptor ne utralizing antibody. Administration of rat recombinant IL-4 led to neo vascularization when implanted in the rat cornea. Findings suggest tha t IL-4 may be a mediator of the immune system as well as an inducer of angiogenesis. (C) 1998 Academic Press.