title: Split tolerance to the MHC class I molecule H-2Dd in animals transgenic for its soluble analog.
abstract: To determine whether the function of MHC molecules in tolerance and education is related to cell surface expression, we have produced two strains of transgenic mice in the C57Bl/6 background that express soluble analogs of the H-2D(d) class I protein. The transgenes were stably integrated and genetically transmitted in a Mendelian fashion. Messenger RNA for the hybrid genes was detected in all tissues analyzed in a class I-like pattern of expression, with the highest levels in lymphoid tissues. All mice bearing the transgenes expressed relatively high levels (0.1 mg/ml) of the encoded protein in their serum as assessed by Western blotting and enzyme-linked immunosorbent assay (ELISA). Gel filtration chromatography showed that the soluble H-2D(d) protein exists as a heterodimer with beta2-microglobulin and as higher order multimers in serum. Lymphoid cells from the transgenic mice showed no cell surface expression of the soluble class I protein in indirect immunofluorescence assays. Splenocytes from two independently derived transgenic lines generated primary cytotoxic and proliferative responses directed against membrane H-2D(d) antigens. Mice of both strains rejected tail skin from donors that differed from the B6 background at the H-2D(d) locus only, but with delayed kinetics compared to nontransgenic littermate controls. Mice expressing the transgenic protein on immunization did not produce antibodies that recognized soluble H-2D(d) in ELISA, whereas B6 mice generated strong antibody responses to challenge with splenocytes bearing cell surface H-2D(d). Thus, transgenic mice expressing soluble H-2D(d) were partially tolerant to stimulation by membrane-bound H-2D(d). As with the activation of T-cells, the induction and maintenance of immunologic tolerance apparently displayed different requirements depending upon the T-cell subpopulation involved.
authors.affiliation: Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-1892, U.S.A.
authors.forename: R D
authors.initials: RD
authors.lastname: Hunziker
authors.forename: F
authors.initials: F
authors.lastname: Lynch
authors.forename: E M
authors.initials: EM
authors.lastname: Shevach
authors.forename: D H
authors.initials: DH
authors.lastname: Margulies
mesh_terms: D000818:Animals; D003602:Cytotoxicity, Immunologic; D005260:Female; D006084:Graft Rejection; D006183:H-2 Antigens / Q000097:blood / Q000737:chemistry / Q000235:genetics; D064532:Histocompatibility Antigen H-2D; D007108:Immune Tolerance / Q000235:genetics; D007518:Isoantibodies / Q000096:biosynthesis; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008822:Mice, Transgenic; D011247:Pregnancy; D011487:Protein Conformation; D016038:Skin Transplantation / Q000276:immunology; D013154:Spleen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology; D014184:Transplantation, Homologous
chemical_list: D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D007518:Isoantibodies