TISSUE & CELL 1987 19 (4) 463-467 @ 1987 Longman Group UK Ltd M. E. SCHELLING”, J. R. HAWKER, Jr. and H. J. GRANGER IMMUNOCHEMICAL COMPARISON OF PEPTIDE ANGIOGENIC FACTORS Keywords: Angiogenic peptides, heparin-binding growth factors, endothelial mitogens, angiogenesis ABSTRACT. A panel of 40 monoclonal antibodies was constructed in response to cationic endothelial cell growth factor (c-ECGF), the cationic peptide mitogen isolated from endothelial mitogen. The monoclonal antibodies were assayed by dot blot for immunoreactivity to various other peptide angiogenic factors. The panel of monoclonal antibodies to c-ECGF exhibited complete cross-reactivity with pituitary fibroblast growth factor and sarcoma-derived growth factor. A group of 28 monodonal antibodies was found to exhibit reactivity to anionic endothelial mitogen (a-ECGF), brain tibroblast growth factor, endothelial cell growth factor, and retina-derived growth factor. None of the monoclonal antibodies was found to react with epidennal growth factor or platelet-derived growth factor. These data provide an immunological basis for grouping heparin-binding endothelial cell growth factors into anionic and cationic groups. Introduction Angiogenesis, or neovascularization, is involved in wound healing, pathophysiologi- cal processes such as diabetic retinopathy, and as a control point in tumor growth. The angiogenic process consists of two compon- ent processes: endothelial cell proliferation and migration. Various peptide angiogenic factors have been found to elicit the prolifera- tion and migration of endothelial cells. Anionic and cationic peptide angiogenic fac- tors have been isolated from hypothalamus (Klagsbrun and Shing, 1985; Maciag zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONML et al., 1984), pituitary (Gospodarowicz, 1975), brain (Gospodarowicz et al., 1975; Thomas et al., 1984; Conn and Hatcher, 1984; Gimenez- Gallego et al., 1985; Lobb and Fett, 1984), and eyes (Courty et al., 1985; D’Amore and Klagsbrun, 1984). Angiogenic peptides have also been isolated from tumors (Shing et al., 1984; Fett et al., 1985), cartilage (Sullivan and Klagsbrun, 1985), and macrophages (Baird et al., 1985). Many peptide ‘To whom offprint requests should be sent. Address: Microcirculation Research Institute, Department of Medical Physiology, Texas A&M University College of Medicine, College Station, Texas 77843, U.S.A. 463 endothelial cell mitogens share the property of heparin binding (Lobb et al., 1986) and potentiation of the proliferation response in the presence of heparin (Thornton et al., 1983; Schreiber et al., 1985). The interrelationships between the various angiogenic peptides are gradually being elucidated. Lobb et al. (1986) suggested the division of heparin-binding growth factors into two classes based on differential affinity for heparin. Class 1 contains anionic peptides of molecular weight 15-17 kD, including acidic brain fibroblast growth factor and retina-derived growth factor. Class 2 pep- tides are cationic mitogens of molecular weight 18-20 kD. Pituitary fibroblast growth factor, cartilage-derived growth factor, and certain tumor-derived growth factors are included in class 2 on the basis of similar chromatographic and electrophoretic pro- perties, and similar amino acid compositions. Schreiber et al. (1985) observed that acidic fibroblast growth factor and bovine eye- derived growth factor II were recognized by two-anionic endothelial cell growth factor (a-ECGF) monoclonal antibodies and com- peted with iodinated a-ECGF for binding to bovine aortic endothelial cells and human umbilical vein endothelial cells.