Abstract: This application relates to methods and compositions for inducing immune tolerance. Specifically, methods and uses of regulatory T cells (Treg) and associated compositions for the induction of immune tolerance are described. The methods and uses may be used to prevent transplant rejection, and in the treatment of diseases or conditions such as graft versus host disease, autoimmune disease and allergies. Also provided are transgenic mice that ubiquitously express FGL2 protein from which the Treg may be isolated.

Abstract: A cyclosporine metabolite having a molecular weight determined by mass spectrometry of about 1205 and having the following properties: (a) being immunologically distinct from cyclosporine metabolites OL-1, OL-17 and OL-8; (b) being more polar than OL-1 or OL-17 and less polar than OL-8 when eluated from a gradient high performance liquid chromatography; (c) being extractable from bile of test animals which have been administered cyclosporine A; and (d) being substantially free of other cyclosporine metabolites and cyclosporine A, and a physiologically acceptable salt or stereoisomer thereof.