Gamma Interferon Induced Organ Regeneration

Introduction

Injury in the adult human is typically followed by the healing response which includes the laying down of a disordered collagen matrix [1-4]. This scar or fibrotic response has been postulated to be one of the impediments to regeneration of the damaged organ [1-4].

The adult salamander is the most well studied model of vertebrate organ and tissue regeneration in the adult [1-4]. An adult salamander can grow exact replacements for severed limbs and other lost body parts.

The early stages of tissue injury in the salamander and the adult human are similar. However, while a scar forms in humans at the site of tissue organ injury, scarring does not occur in the salamander. Instead, the salamander reactivates an embryonic development program to repair or replace the large body part (tissue or organ) [1-4].

Gamma interferon has been postulated to be a useful inhibitor of fibrosis [5]. However, to date gamma interferon has not shown activity in human fibrotic disease. In fact, in one study where gamma interferon was administered subcutaneously, it failed in a trial of pulmonary fibrosis [6]. I postulate this failure was due to the lack of local suprapharmacologic dosing of gamma interferon.