Growing organs for transplantation from embryonic precursor tissues

Abstract

The use of pig fetal precursor tissues can answer the shortage of organs for transplantation. Our data pinpoint a window of time in pig fetal kidney, pancreas, liver, spleen, and lung organogenesis that may be optimal for transplantation into mature recipients. Window transplants are defined by their remarkable ability to grow, differentiate, and undergo vascularization, achieving successful organogenesis of a functional organ. The transplanted tissue shows no evidence of transdifferentiation or tumorigenicity and displays reduced immunogenicity compared to its adult counterparts. Interestingly, this window might vary between different tissues. Perhaps the most advanced candidate for clinical translation is the pig embryonic pancreatic application shown recently to be capable of complete reversal of diabetes in nonhuman primates. This later achievement was largely based on studies in immune deficient mice, in which E42 pig pancreatic tissue has been identified as the tissue of choice, based on its long-term growth potential, functionality, response to glucose challenge, endocrine/exocrine ratio, vasculature pattern, and reduced immunogenicity compared to adult tissue.