title: Bulk purification of a naturally occurring soluble form of RT1-A class I major histocompatibility complex antigens from DA rat liver, and studies of specific immunosuppression.
abstract: We describe the bulk purification of a water-soluble form of RT1-A class I MHC antigens from aqueous extracts of DA liver. Using a combination of monoclonal antibody affinity, lentil lectin affinity, and gel permeation chromatography, we were able to obtain large quantities of pure water-soluble RT1-A antigens. Typically, from 40 DA livers, 0.5 mg of pure antigen with antigen activity equivalent to 7 X 10(9) nucleated DA spleen cells was obtained. The water-soluble RT1-A molecule had a discrete heavy chain of 40 kD, linked noncovalently to beta 2 microglobulin. The heavy chain of the water-soluble RT1-A molecule was 5 kD smaller than the membrane-bound form of RT1-A from DA liver membranes. The smaller molecule probably represents a secreted form of RT1-A class I molecules that lack the transmembrane domain (exon 5). Large quantities of this water-soluble RT1-A class I antigen from the DA strain, given intravenously to PVG recipients of DA cardiac allografts by a variety of protocols, did not have any effect on graft survival. The fairly ready availability of milligram quantities of pure class I transplantation antigens should be of considerable value for studies in transplantation.
authors.forename: S C
authors.initials: SC
authors.lastname: Spencer
authors.forename: J W
authors.initials: JW
authors.lastname: Fabre
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002846:Chromatography, Affinity; D006085:Graft Survival; D016027:Heart Transplantation; D006649:Histocompatibility Antigens / Q000008:administration & dosage / Q000276:immunology / Q000302:isolation & purification*; D007108:Immune Tolerance; D008099:Liver / Q000276:immunology*; D051381:Rats; D011919:Rats, Inbred Strains / Q000276:immunology; D012995:Solubility; D014867:Water
chemical_list: D000911:Antibodies, Monoclonal; D006649:Histocompatibility Antigens; C038353:histocompatibility antigens RT, rat; D014867:Water