Hybrid spheroids of urine-derived renal epithelial cells: Structural and functional characterization

Urine-derived Renal Epithelial Cells (URECs) are voided in urine after acute kidney damage and in response to ischemia reperfusion events. We previously investigated the phenotype and immunomodulatory properties of URECs derived from kidney transplanted patients. Here, we establish a 3D model combining URECs with Wharton's Jelly Mesenchymal Stromal Cells (WJ-MSCs), to evaluate structure, cell distribution and viability of the spheroids. Immunomodulatory properties were analysed by coculturing spheroids with Peripheral Blood Mononuclear Cells (PBMCs); CD4⁺ and CD8⁺ T cells proliferation, and the percentage of regulatory T cells (Treg) and Granzyme B⁺ cells were evaluated. Spheroids were obtained combining URECs and WJ-MSCs, with URECs located in the core of the aggregate and WJ-MSCs in the outer layer. In a PBMC co-culture system, hybrid spheroids reduced CD4⁺ and CD8⁺ T cells proliferation, and the Granzyme B⁺ cells percentage, while increasing Tregs. Our data demonstrate the stability and immunomodulatory capacity of URECs:WJ-MSCs spheroids, providing a basis to investigate immunomodulatory pathways and unexplored effects of this novel 3D cell model.