The Therapeutic Effects of Human Embryonic Stem Cells-derived Immunity-and-matrix Regulatory Cells on Membranous Nephropathy

Abstract Background Primary membranous nephropathy (MN) is a kidney-specific autoimmune disease. Human embryonic stem cells-derived immunity-and-matrix regulatory cells (hESC-IMRCs) have immunoregulatory functions. We hypothesized that hESC-IMRCs might have therapeutic effects on MN and be a potential treatment in clinical practice. Methods Rats of Heymann nephritis were set up by immunization with sheep anti-rat Fx1A serum. hESC-IMRCs were intravenously administrated upon the detection of proteinuria, with 6×106 cells (high-dose) or 3×106 cells (low-dose) in 1 ml every other day. Splenocytes and IMRCs were co-cultured at different times and ratios. Cell types and cytokines were detected by flow cytometry and enzyme-linked immunosorbent assay. Results Proteinuria of rats with Heymann nephritis was reduced remarkably to a level comparable to negative controls, in both low-dose (45.6 vs. 282.3 mg/d, P<0.001) and high-dose (35.2 vs. 282.3 mg/d, P<0.001) hESC-IMRC treatment groups. IgG and C3 deposit, glomerular basement membrane thickness (613.6 vs. 1014.3 nm, P=0.003) and foot process effacement (271.0 vs. 496.4 nm, P<0.001) was alleviated in the kidneys. The proportions of CD4+CD25+ T cells in circulation (7.2 vs. 3.4%, P=0.002) and in spleen (14.9 vs. 10.0%, P<0.001) were increased, the circulating level of IL-10 was increased (42.1 vs. 27.4 pg/ml, P<0.001), and the circulating level of complement C3 was decreased (464.2 vs. 872.7 ng/ml, P=0.010), after hESC-IMRC interventions. IL-10 increased remarkably in the co-culture supernatant of lymphocytes and IMRCs at 48 hours with ratio 10:1. Conclusions The intravenously delivered hESC-IMRCs alleviated proteinuria and kidney injuries of Heymann nephritis, by their immunosuppressive functions through regulatory T cells and IL-10. These pre-clinical results indicate that IMRCs worth careful consideration for human trials in the treatment of MN.