XENOGENEIC CELL THERAPY - CURRENT PROGRESS AND FUTURE-DEVELOPMENTS INPORCINE CELL TRANSPLANTATION

The multitude of distinct cell types present in mature and developing tissues display unique physiologic characteristics. Cellular therapy i s a novel technology with the promise of utilizing this diversity to t reat a wide range of human degenerative diseases. Intractable diseases , disorders, and injuries are characterized by cell death or aberrant cellular function. Cell transplantation can replace diseased or lost t issue to provide restorative therapy for these conditions, The limited use of cell transplants as a basis for current therapy can, in part, be attributed to the lack of available human cells suitable for transp lantation. This has prevented further realization of the promise of ce ll transplantation as a platform technology. Accordingly, cell-based t herapies such as blood transfusions, for which the cells are readily a vailable, are a standard part of current medical practice. Despite num erous attempts to expand primary human cells in tissue culture, curren t technological limitations of this approach in regard to proliferativ e capacity and maintenance of the differentiated phenotype has prevent ed their use for transplantation. Further, use of human stem cells for the derivation of specific cell types for transplantation is an area of future application with great potential, but hurdles remain in rega rd to deriving and sufficiently expanding these multipotential cells. Thus, it appears that primary cells are at present a superior source f or transplantation. This review focuses on pigs as a source of a varie ty of primary cells to advance cell therapy to the clinic and implemen t achievement of its full potential. We outline the advantages and dis advantages of xenogeneic cell therapy while underscoring the utility o f transplantable porcine cells for the treatment of human disease. (C) 1998 Elsevier Science Inc.