Enhanced propagation of adult human renal epithelial progenitor cells to improve cell sourcing for tissue-engineered therapeutic devices for renal diseases.

Renal cell therapy employing cells derived from adult renal epithelial cell (REC) progenitors promises to reduce the morbidity of patients with renal insufficiency due to acute renal failure and end stage renal disease. To this end, tissue engineered devices addressing the neglected biologic component of renal replacement therapy are being developed. Because human donor tissue is limited, novel enhanced progenitor cell propagation (EP) techniques have been developed and applied to adult human kidney transplant discards from six donors. Changes include more efficient digestion and the amplification of progenitors prior to terminal epithelial differentiation promoted by contact inhibition and the addition of retinoic acid. Differentiated morphology in EP populations was demonstrated by the ability to form polarized epithelium with tight junctions, apical central cilia and expression of brush border membrane enzymes. Evaluation of lipopolysaccharide stimulated interleukin-8 secretion and γ-glutamyl transpeptisade activity in EP derived cells was used to confirm therapeutic equivalence to REC obtained using published techniques, which have previously shown efficacy in large animal models and clinical trials. Yield exceeded 10(16) cells/gram cortex from the only kidney obtained due to an anatomical defect, while the average yield from diseased kidneys ranged from 1.1 × 10(9) to 8.8 × 10(11) cells/gram cortex, representing an increase of more than 10 doublings over standard methods. Application of the EP protocol to REC expansion has solved the problem of cell sourcing as the limiting factor to the manufacture of cell based therapies targeting renal diseases and may provide a method for autologous device fabrication from core kidney biopsies.