Shimizu Ichiro, Tomita Yukihiro, Iwai Toshiro, Kajiwara Takashi, Okano Shinji, Nomoto Kikuo, Tominaga Ryuji
Department of Cardiovascular Surgery, Kyushu University, Fukuoka, Japan.
Scand J Immunol. 2006 Jun;63(6):435-43. doi: 10.1111/j.1365-3083.2006.001763.x.
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.
此前，我们已经表明，环磷酰胺（CP）诱导的耐受性，其特征为永久接受供体皮肤移植并建立供体混合嵌合体，通过供体脾细胞（SC）、CP、白消安（BU）和供体骨髓细胞（BMC）治疗很容易诱导产生。在此，我们在α1,3-半乳糖基转移酶缺陷型敲除小鼠（GalT KO；GalT-/-，H-2(b/d)）的CP诱导耐受性系统中，研究了产生抗供体天然抗体（nAb）的B细胞耐受性机制。使用供体AKR SC和BMC诱导耐受性后，分析受体GalT KO小鼠中供体心脏和皮肤移植的存活情况以及抗Galα1-3Galβ1-4GlcNAc（抗αGal）抗体的产生。此外，在用兔红细胞（RRBC）和CP处理后，通过流式细胞术（FCM）分析GalT KO小鼠中抗αGal抗体的产生以及Gal-BSA结合B细胞的存在情况。用供体SC + CP/BU + BMC处理的GalT KO小鼠实现了对供体皮肤和心脏移植的永久接受以及抗αGal抗体的消除。然而，在用供体SC和CP处理的GalT KO小鼠中，尽管未检测到抗αGal抗体，但供体皮肤移植仍被急性排斥。同样，在用RRBC和CP处理的GalT KO小鼠中未检测到抗αGal抗体。我们的数据强烈表明了以下机制：在用RRBC和CP进行传统预处理后，早期的克隆破坏以及后期的克隆无能或忽视。总之，我们的药物诱导耐受性方案对于在产生抗供体nAb的受体中诱导耐受性是有效的。
