Organ culture of gastrointestinal mucosa--a technique for the study of the human gastrointestinal tract.

Organ culture developed about 50 years ago, mainly for the study of morphogenesis in embryological tissue. Fell and co-workers in Cambridge studied many embryological events in vitro (Fell, 1940), and organ culture came to be defined as that type of culture where complete rudiments or fragments of organs were cultivated with a minimum of outgrowth and enlarged as a whole (Fell, 1953; Parker, 1961). Organ culture thus provided a means of preserving normal histological structure in vitro and of supporting normal embryological development. Trowell successfully applied the technique to adult animal tissue, reporting his definitive method of organ culture in 1959. He successfully maintained pieces of several adult rat organs in vitro for up to 10 days. He did not attempt to culture gastrointestinal tissue, stating that he thought the problem of infection would be too great (Trowell, 1961). It was not until 1969 that Browning and Trier reported a method for maintaining adult human intestinal mucosal biopsies in vitro for a 24-hr period using Trowell's technique. Since then several groups of workers have used the technique to study human gastrointestinal mucosa. It seems an ideal tool with which to study diseases of the gastrointestinal mucosa such as coeliac disease or ulcerative colitis. Using such a technique of culture, studies can be performed with control over various factors affecting the tissue. Although care should be exercised in extrapolating conclusions from in vitro experiments to the in vivo situation, such cultures are useful for the study of disease where there is no animal model or naturally occurring animal disease with which to compare it. Katz and Grand (1979) summarized the potential of organ culture of gastrointestinal tissue by stating "it is clear that intestinal organ culture offers an opportunity to characterize specific cellular abnormalities induced by various types of mucosal injury, to study the effects ofoffending antigens on intestinal structure and function, and to identify abnormalities in local immune function induced by such in vitro exposure". It is hoped to show in this review that some of this potential has been realised, particularly in relation to the study of coeliac disease.