Division of Gastroenterology and Hepatology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
Hepatology. 2013 Jan;57(1):239-48. doi: 10.1002/hep.25579. Epub 2012 Jul 17.
Immunosuppression (IS) withdrawal from calcineurin inhibitors is only possible in ≈ 20% of liver transplant recipients. However, mammalian target of rapamycin inhibitors (e.g., sirolimus; SRL) appear to be more immunoregulatory and might promote a tolerant state for withdrawal. Our aim was to determine whether systemic (i.e., blood, marrow, and allograft) signatures of immunoregulation are promoted by conversion from tacrolimus (TAC) to SRL. We therefore performed the following serial assays before and after SRL conversion in liver transplant recipients to test for enhanced markers of immunoregulation: (1) flow-cytometry immunophenotyping of peripheral blood mononuclear cells (PBMCs) and bone marrow aspirates for regulatory T cells (Tregs) (e.g., CD4(+) CD25(+++) FOXP3(+) ) and regulatory dendritic cells (DCregs) (immunoglobulin-like transcript 3(+) /4(+) ); (2) liver biopsy immunohistochemical staining (e.g., FOXP3:CD3 and CD4:CD8 ratios) and immunophenotyping of biopsy-derived Tregs after growth in culture; (3) effects of pre- versus postconversion sera on Treg generation in mixed lymphocyte reactions; (4) peripheral blood nonspecific CD4 responses; and (5) peripheral blood gene transcripts and proteomic profiles. We successfully converted 20 nonimmune, nonviremic recipients (age, 57.2 ± 8.0; 3.5 ± 2.1 years post-liver transplantation) from TAC to SRL for renal dysfunction. Our results demonstrated significant increases in Tregs in PBMCs and marrow and DCregs in PBMCs (P < 0.01) after conversion. In biopsy staining, FOXP3:CD3 and CD4:CD8 ratios were significantly higher after conversion and a number of biopsy cultures developed new or higher FOXP3(+) cell growth. Nonspecific CD4 responses did not change. Both pre- and postconversion sera inhibited mixed lymphocyte reactions, although only TAC sera suppressed Treg generation. Finally, 289 novel genes and 22 proteins, several important in immunoregulatory pathways, were expressed after conversion.
TAC to SRL conversion increases systemic Tregs, DCregs, and immunoregulatory proteogenomic signatures in liver transplant recipients and may therefore facilitate IS minimization or withdrawal.
只有约 20%的肝移植受者能够从钙调神经磷酸酶抑制剂中撤免免疫抑制。然而，雷帕霉素哺乳动物靶标抑制剂（如西罗莫司；SRL）似乎具有更强的免疫调节作用，并可能促进撤免后的耐受状态。我们的目的是确定从他克莫司（TAC）转换为 SRL 是否会促进全身性（即血液、骨髓和移植物）免疫调节的特征。因此，我们在肝移植受者转换为 SRL 前后进行了以下系列检测，以测试增强的免疫调节标志物：（1）通过流式细胞术对外周血单个核细胞（PBMC）和骨髓抽吸物进行免疫表型分析，以检测调节性 T 细胞（Tregs）（例如，CD4(+) CD25(+++) FOXP3(+)）和调节性树突状细胞（DCregs）（免疫球蛋白样转录物 3(+) /4(+)）；（2）肝活检免疫组织化学染色（例如，FOXP3:CD3 和 CD4:CD8 比值）和在培养中生长后的活检衍生 Tregs 的免疫表型分析；（3）转换前后血清对混合淋巴细胞反应中 Treg 生成的影响；（4）外周血非特异性 CD4 反应；和（5）外周血基因转录物和蛋白质组学谱。我们成功地将 20 名非免疫、非病毒血症的受者（年龄 57.2 ± 8.0；肝移植后 3.5 ± 2.1 年）从 TAC 转换为 SRL 以治疗肾功能障碍。我们的结果表明，转换后 PBMC 和骨髓中的 Tregs 和 PBMC 中的 DCregs 显著增加（P < 0.01）。在活检染色中，转换后 FOXP3:CD3 和 CD4:CD8 比值显著升高，一些活检培养物出现新的或更高的 FOXP3(+)细胞生长。非特异性 CD4 反应没有变化。转换前后的血清均可抑制混合淋巴细胞反应，尽管只有 TAC 血清可抑制 Treg 的生成。最后，转换后表达了 289 个新基因和 22 种蛋白质，其中一些在免疫调节途径中很重要。
TAC 转换为 SRL 可增加肝移植受者的全身 Tregs、DCregs 和免疫调节蛋白质组学特征，从而可能促进免疫抑制的最小化或撤免。
