A NOVEL MUTEIN OF TNF-ALPHA CONTAINING THE ARG-GLY-ASP SEQUENCE SHOWSREDUCED TOXICITY IN INTESTINE

The effects of human tumour necrosis factor-alpha (TNF alpha), or its mutein (F4168) having the cell adhesive Arg-Gly-Asp sequence at the N- terminus, on intestinal injury, were examined Histopathological examin ation revealed that an intravenous injection of TNF alpha resulted in marked haemorrhage or oedema in the caecum of rats, whereas F4168 show ed no such effects even at the same therapeutic dose. Moreover, the nu mber of neutrophils that adhered to endothelial cells or infiltrated t he mucosal tissue was much higher after TNF alpha injection compared w ith F4168 in vivo. The enhanced adhesion of neutrophils on to human um bilical vein endothelial cells also occurred when the latter were pre- stimulated with TNF alpha but not with F4168 in vitro. The expression of the cell adhesion molecules Including endothelial leukocyte adhesio n molecule-1 or intercellular adhesion molecule-1 on F4168- stimulated human umbilical vein endothelial cells was significantly lower than t hat stimulated with TNF alpha. These results suggest that the Arg-Gly- Asp sequence introduced into the TNF alpha molecule abrogates the side effect of this cytokine such as tissue injury or shock, and that F416 8 could be useful for systemic therapy.