Decreased immunogenicity of fetal kidneys: The role of passenger leukocytes

Renal Organogenesis from Transplanted Metanephric Primordia

“…A state of peripheral immune tolerance secondary to T cell 'ignorance' permits the survival of transplanted metanephroi. Most likely the ignorance results from the absence of APC originating from the donor in the embryonic renal tissue and the consequent absence of direct presentation of transplant antigen to host T cells (presentation by donor dendritic cells to host T cells) (20), as was shown previously for sub-renal capsular transplants (14).…”

“…Velasco and Hegre (14) transplanted metanephroi or liver tissue from E15, E17, E18, and E19 Fisher rat embryos (RT1 l v1) beneath the renal capsule of MHC (RT1) incompatible Wistar Furth adult rats (RT1 u ). All fetal hepatic grafts were rejected by 10 d posttransplantation.…”

“…It was speculated that the absence of APC in metanephroi obtained from E15 embryos together with their presence in liver tissue obtained concurrently could explain the differential fate of metanephroi transplanted with or without liver. Under the former conditions, but not the latter, direct presentation of donor antigens to host T cells could take place (14).…”

Therapeutic Promise of Embryonic Kidney Transplantation

“…The possibility of employing such a strategy in lieu of transplantation of developed kidneys has been the subject of investigation for at least two decades. Isograft, allograft and xenograft metanephroi have been transplanted successfully to a number of sites including the chorioallantoic membrane of developing birds [6], the anterior chamber of the eye [7]beneath the renal capsule [7, 8, 9, 10, 11, 12, 13, 14], and intra-peritoneally [9, 12, 15, 16, 17, 18, 19, 20, 21]. Some of the studies conducted during the past 20 years are listed in table 1.…”

Stem Cell Approaches for the Treatment of Renal Failure

“…Several mechanisms are thought to account for this observation (Hammerman, 2003), including absence of antigen-presenting cells within the metanephros prior to a certain stage in development (Foglia et al, 1986;Velasco and Hegre, 1989), reduced expression levels of major histo-STEM CELL APPROACHES FOR THE TREATMENT OF RENAL FAILURE compatibility class I and II antigens (Statter et al, 1989;Dekel et al, 1997), and altered expression levels of cytokines, chemokines, and cytolytic effector molecules relative to adult tissue (Dekel et al, 2000). Additionally, vascularization of transplanted metanephroi is accomplished, at least in part, by host blood vessels, resulting in the generation of a chimeric organ shielded to some degree from circulating immune-cell surveillance (Rogers and Hammerman, 2001b).…”