Clinical and experimental transplantation of isolated organ or tissue cells indications problems from the Polish perspective

Clinical cell transplantation remains as a clinical experiment. Morphologically intact and functional cells transplanted into their tissue of origin undergo rapid disintegration by attacking granulocytes and macrophages, leading to the so-called early graft dysfunction. When transplanted to sites remote from their origin, the process of elimination is even faster. Among millions of transplanted cells, only a few survive in an autologous or syngeneic recipient, not to mention an allogeneic combination. What is the mechanism of elimination of the majority of transplanted cells? Which cells survive and what is their genotype and phenotype? There are several problems that should be investigated: (1) the mechanism of anoikis, namely, detachment-induced apoptosis, (2) the reaction of the innate immune system to transplanted cells, (3) the microchimerism created by the transplanted cells, and (4) the "niche" for transplanted cells within the local cell chemical environment and signalling. Our experience with transplantation of hepatocytes illustrates current problems in isolated cell grafting. Proposals to increase the in vivo survival rate of transplanted syngeneic hepatocytes are essential to the vision of the future of cell transplantation.