title: Sequential analysis of anti-alpha Gal natural antibody-producing B cells in GalT knockout mice in cyclophosphamide-induced tolerance.
abstract: Previously, we have shown that cyclophosphamide (CP)-induced tolerance, marked by permanent acceptance of donor skin graft and establishment of donor mixed chimerism, was readily induced with treatment with donor spleen cells (SC), CP, busulfan (BU) and donor bone marrow cells (BMC). Here, we investigated the mechanism of anti-donor natural antibody (nAb) producing B-cell tolerance in our CP-induced tolerance systems in alpha1,3-galactosyltransferase-deficient knockout mice (GalT KO; GalT-/-, H-2(b/d)). After induction of tolerance using donor AKR SC and BMC, survival of donor heart and skin grafts and production of anti-Galalpha1-3Galbeta1-4GlcNAc (anti-alphaGal) Ab in recipient GalT KO mice were analyzed. In addition, the production of anti-alphaGal Ab and the presence of Gal-BSA binding B cells in GalT KO mice were analyzed by flow cytometry (FCM) after treatments with rabbit red blood cells (RRBC) and CP. Permanent acceptance of donor skin and heart grafts and abrogation of anti-alphaGal Ab were achieved in GalT KO mice treated with donor SC + CP/BU + BMC. However, in the GalT KO mice treated with donor SC and CP, donor skin grafts were acutely rejected, even though anti-alphaGal Ab was undetectable. Similarly, anti-alphaGal Ab was undetectable in GalT KO mice treated with RRBC and CP. Our data strongly indicated the following mechanisms: the clonal destruction in the early stage and the clonal anergy or ignorance in the late stage after conventional conditioning with RRBC and CP. In conclusion, our drug-induced tolerance protocols are effective to induce tolerance in recipients that produce anti-donor nAb.
authors.affiliation: Department of Cardiovascular Surgery, Kyushu University, Fukuoka, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Shimizu
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Tomita
authors.forename: Toshiro
authors.initials: T
authors.lastname: Iwai
authors.forename: Takashi
authors.initials: T
authors.lastname: Kajiwara
authors.forename: Shinji
authors.initials: S
authors.lastname: Okano
authors.forename: Kikuo
authors.initials: K
authors.lastname: Nomoto
authors.forename: Ryuji
authors.initials: R
authors.lastname: Tominaga
mesh_terms: D000818:Animals; D016175:B-Lymphocyte Subsets / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D016026:Bone Marrow Transplantation / Q000276:immunology; D002066:Busulfan / Q000008:administration & dosage / Q000494:pharmacology; D017635:Clonal Anergy / Q000187:drug effects*; D003520:Cyclophosphamide / Q000008:administration & dosage / Q000494:pharmacology*; D017707:Erythrocyte Transfusion; D005260:Female; D005700:Galactosyltransferases / Q000172:deficiency* / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D006085:Graft Survival / Q000235:genetics / Q000276:immunology; D016027:Heart Transplantation / Q000276:immunology; D007518:Isoantibodies / Q000096:biosynthesis*; D051379:Mice; D018345:Mice, Knockout; D016513:Mice, SCID; D011485:Protein Binding / Q000276:immunology; D011817:Rabbits; D016038:Skin Transplantation / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000637:transplantation; D019172:Transplantation Conditioning; D014312:Trisaccharides / Q000276:immunology* / Q000378:metabolism
chemical_list: D007518:Isoantibodies; D014312:Trisaccharides; C076569:alpha-galactosyl epitope; D003520:Cyclophosphamide; D005700:Galactosyltransferases; C487611:alpha 1,3 galactosyltransferase, mouse; D002066:Busulfan