Experimental immuno‐alteration

Publisher Website
Google Scholar
Abstract
In the past few years, remarkable advances have been made in preventing rejection of islet allografts and xenografts (rat to mouse) by 6 procedures which do not involve continuous immunosuppressive therapy of recipient rodents. Four methods alter or destroy passenger lymphoid cells in the islets prior to transplantation. These include in vitro culture of donor rat islets at low temperature and a single injection of anti‐lymphocyte serum in the recipients, culture of rat or mouse islet aggregates in 95% O2, and pretreatment of mouse islets with Ia antibody and complement or with a monoclonal antidendritic cell antibody and complement. Two methods induce partial tolerance in recipients by preimmunization with donor blood treated either with Ia antibody and complement or ultraviolet irradiation. These preimmunization procedures permit the use of untreated donor islets.Two methods have been developed for the mass isolation of canine islets. Initial studies indicate that low‐temperature culture of donor canine islets and a single injection of anti‐lymphocyte serum will prevent rejection of canine islet allografts. The technical problems remaining for human islet allografts are selection of the optimum method of preventing islet allograft rejection based on studies in the dog, adaptation of the mass islet isolation techniques to the human pancreas, and selection of a safe and optimum site for transplantation.