Urine-derived renal tubular epithelial cells resemble functional characteristics of professional antigen-presenting cells and can directly induce BKV-specific T cell responses

Abstract

Background: Reactivation of the BK virus (BKV) is a critical adverse event after kidney transplantation and can lead to graft loss. BKV-reactive T cell-mediated viral control can be facilitated by reducing immunosuppression. However, the exact mechanism underlying the T cell-mediated BKV clearance in the kidney transplant is not clear. Methods: Here, we used urine-derived renal tubular epithelial cells as a model system to investigate the immunomodulatory capacity of urine-derived renal tubular epithelial cells and their potential to induce T cell responses against BKV. Urinederived renal tubular epithelial cells were generated by culturing urine-derived cell pellets. To assess the inflammatory potential of urine-derived renal tubular epithelial cells, the cells were treated with Poly I:C or TNFα/IFNγ. To investigate urine-derived renal tubular epithelial cell-induced T cell responses, autologous T cells, isolated from blood were co-cultured with urine-derived renal tubular epithelial cells, in the presence of BKV protein-derived peptides and PolyI:C or TNFα/ IFNγ. BKV-reactive T cells, ytokine/chemokine secretion and expression of co-stimulatory molecules were evaluated using multiplex ssays and multi-parameter flow cytometry.