Fetal kidneys modulate the allogeneic immune response by a synergistic effe
ct: first, fetal kidney tissue tropism is abrogated by the initial relative
lack of adhesion molecules. Second, the reduced expression of major histoc
ompatibility complex (MHC) determinants is less effective in inducing the a
lloantigen-primed T cell response, which in turn induces the downregulation
of Th 1 cytokines, beta chemokines, and Fas ligand, but spares protective
Th2 cytokines, and leads to minimal induction of MHC and adhesion molecules
on immature renal parenchymal elements. Thus, at the onset and during this
altered rejection process, cellular recruitment to the fetal renal site is
less prominent than to the adult renal tissue, and effector cells in the f
etal graft are less activated.