Tju103和CTLA4-Ig诱导MHC半相合小鼠骨髓移植耐受比较

目的：观察Tju103和CTLA4—Ig各自对MHC半相合小鼠骨髓移植免疫耐受的诱导。方法：半相合供鼠T细胞与受鼠抗原、Tju103(或CTLA4—Ig)共育后与骨髓细胞混合移植，观测移植后受情况。结果：A．单纯照射组：全部小鼠于照射后11d内死于造血衰竭；B．白血病CTX治疗组：全部小鼠于接种白血病细胞后16—23d死于白血病；C．单纯移植组：全部小鼠于移植后21d内死于移植物抗宿主病(GVHD)；D．CsA预防组：5只小鼠于移植后8—22d死亡，1只死于白血病，各有2只死于GVHD和感染，5只活过30d；E．Tju103处理组：4只小鼠于移植后9～26d死亡，2只死于GVHD，各有1只死于白血病和感染，6只活过30d；F．CTLA4—Ig处理组：2只小鼠于移植后17—26d死亡GVHD，8只活过30d。结论：Tju103和CTLA4—Ig均明显延长生存期，降低GVHD发生和严重程度，CTLA4—Ig保留有抗感染和移植抗白血病(GVL)作用，而Tju103没有。     

A gut microbiota score predicting acute graft‐versus‐host disease following myeloablative allogeneic hematopoietic stem cell transplantation

Although studies have reported that intestinal microbiota are associated with acute graft‐versus‐host disease (aGVHD), they lacked a satisfactory method for predicting aGVHD. We collected stool and blood samples at day 15 posttransplant from 150 patients from two centers who underwent myeloablative conditioning allogeneic hematopoietic stem cell transplantation (allo‐HSCT). Stool microbiota were detected by 16S ribosomal RNA gene sequencing; inflammatory factors and T lymphocytes were detected by multiplex immunoassays and flow cytometry, respectively. A gut microbiota score (GMS) from a LASSO (least absolute shrinkage and selection operator) model was developed and validated to predict aGVHD. In the discovery cohort, the GMS could predict II‐IV aGVHD (area under the receiver operating characteristic [ROC] curve [AUC] = 0.904, P < .0001). Furthermore, the validation model was consistent with the discovery set (AUC = 0.887, P < .0001). Regulatory T/T‐helper 17 (Treg/Th17) cells ratio in the low GMS subgroup was higher compared with the high GMS (P = .012), and the validation set is consistent with the discovery set (P = .003). In addition, high cytokine levels were associated with high GMS. In conclusion, the GMS at neutrophil engraftment could predict aGVHD, and it was a potential and novel method. The GMS was associated with the inflammatory factor and Treg/Th17 balance.     

Alloreactive CD4+ T lymphocytes can exert cytotoxicity to chronic myeloid leukaemia cells processing and presenting exogenous antigen

Existing evidence supports that CD4⁺ T lymphocytes play a role in the graft-versus-leukaemia (GVL) reaction after allogeneic bone marrow transplantation (BMT) for chronic myeloid leukaemia (CML), not only as initiators of the immune response but also as effectors of GVL. In BMT between HLA-identical pairs this CD4-mediated GVL would require CML cells to process and present antigens through MHC class II molecules. To investigate whether CML cells are capable of processing and presenting antigens, and suitable targets for CD4⁺ T-cell-mediated cytotoxicity, we generated HLA-DR1-restricted CD4⁺ cytotoxic T-cell clones that specifically recognized tuberculous purified protein derivative (PPD). We have shown that CML cells and B lymphoblastoid cell line (B-LCL) cells but not PHA-blasts from patients with CML processed exogenous antigen, PPD, and induced proliferative and cytotoxic CD4⁺ T-cell responses. Antigen presentation was blocked by antibodies to HLA-DR but not to MHC class I and by treatment with chloroquine and brefeldin. This indicates that CML cells use a classic MHC class II antigen processing pathway to present PPD antigens to CD4⁺ T cells. Cytotoxicity to CML was shown by antibody blocking studies to be mediated mainly through fas antigen. These findings indicate that donor CD4⁺ T cells alone are sufficient to mediate GVL effects following allogeneic BMT for CML.     

Allogeneic immune replacement as cancer immunotherapy

The graft-versus-leukaemia (GVL) reaction that occurs after allogeneic haematopoietic cell transplantation (HCT) can cure patients with a variety of haematological malignancies. A heightened appreciation of the GVL effect has resulted in the development of reduced intensity transplant approaches, where antitumour effects occur predominantly as a consequence of the transplanted donor immune system. The recent success of these transplants in patients with acute and chronic leukaemias has led to trials investigating for graft-versus-tumour (GVT) effects in patients with treatment-refractory metastatic solid tumours. This review discusses evidence that immune replacement following allogeneic HCT is a potent form of cancer immunotherapy for patients with haematological and non-haematological malignancies.     

Bone Marrow Transplantation for Hematologicai Diseases in Hokkaido--June 1985 to December 1991

Bone marrow transplantation (BMT) was started in Hokkaido in1985. In the present report we have reviewed the clinical outcomeof patients treated with BMT for hematologicai diseases in Hokkaido.Fifty-eight allogeneic and 19 autologous transplants were registeredby December 1991. The underlying diseases consisted of 47 leukemias,14 lymphomas, 10 aplastic anemias and six myelodysplastic syndromes.Among the allogeneic BMT cases, 55 were human leuhocyte antigen(HLA) identical and three were mismatched. Among the autologousBMT patiets, two recieved their marrow purged with 4-hydroperoxycyclophosphamideand five, with monoclonal antibodies and complements. The conditioningregimens used for malignancies were chiefly cyclophosphamide(CY) plus total body irradiation, or busulfan plus CY. In manycases, cytokines were used for rapid recovery of decreased leukocytes.Engraftment was observed in 50 out of 52 evaluated allogeneicand 18 out of 19 autologous transplants. Ten allogeneic patientssuffered from severe acute graft-versus-host diseases (GVHD),and extensive chronic GVHD appeared in 16 patients. Relapseswere observed in four cases of allogeneic BMT and six of autologous.BMT. The major complications were interstitial pneumonitis (IP)and severe infections. Long-term, survival rates were almost60% in both allogeneic and autologous transplants. Mild acuteGVHD and limited chronic GVHD increased the survival rates.The results indicated that substantial problems such as GVHD,IP and relapses must be controlled in the near future for animproved outcome to be made possible.     

Retrospective Comparison of CD34-selected Allogeneic Peripheral Blood Stem Cell Transplantation Followed by CD8-depleted Donor Lymphocyte Infusions with Unmanipulated Bone Marrow Transplantation

We have previously reported the feasibility of allogeneic CD34-selected PBSC transplantation followed by pre-emptive CD8-depleted DLI (study group). In this report, we retrospectively compare the clinical outcome of the 24 patients included in this study with an historical group of 35 patients receiving unmanipulated marrow (BMT group). Patients in the study group had significantly faster neutrophil and platelet recovery and were discharged earlier than BMT patients. The actuarial 150-day (after DLI) probability of developing grade II-IV acute GVHD was 28% for the study group versus 62% for the BMT group (p=0.002). The actuarial 2-year probability of developing chronic GVHD was similar (37 versus 36% (NS)) but chronic GVHD was significantly delayed in the study group (p=0.003). The actuarial 2-year probability of relapse was 30% in the study group versus 33% in the BMT group (NS). The actuarial 2-year probability of survival was 45% in the study group versus 43% in the BMT group (NS). We conclude that allogeneic transplantation of CD34-selected PBSC followed by pre-emptive CD8-depleted DLI is feasible with rapid engraftment and minimizes the risk of severe GVHD. Large prospective trials are required to confirm these results.     

异基因外周血造血干细胞移植后GVHD及GVL的临床观察

目的：对骨髓移植后GVHD及GVL共存的现象进行探讨。方法：对1例异基因外周血造血干细胞移植后GVHD的治疗及白血病复发再缓解过程进行临床观察。结果：该患者移植8个月后并发严重慢性GVHD,长期服用免疫抑制剂治疗GVHD的同时,抑制了GVL效应导致疾病复发。结论：掌握GVHD和复发之间的平衡是决定骨髓移植患者预后的重要因素。     

Comprehensive analysis of the immunomodulatory effects of rapamycin on human T cells in graft-versus-host disease prophylaxis

Graft-versus-host disease (GVHD) is a major cause of toxicity after allogeneic hematopoietic cell transplantation (allo-HCT). While rapamycin (RAPA) is commonly used in GVHD prophylaxis in combination with a calcineurin inhibitor (CNI), the understanding of its mechanism of action on human T cells is still incomplete. Here, we performed an extensive analysis of RAPA effects on human T cells in a humanized mouse model of GVHD, in ex-vivo T cell cultures and in patients given RAPA plus tacrolimus as GVHD prophylaxis after nonmyeloablative allo-HCT. We demonstrate that RAPA mitigates GVHD by decreasing T cell engraftment and differentiation, inhibiting CD8⁺ T cell activation and increasing the long-term IL-2 secretion, thereby supporting regulatory T cell (Treg) proliferation. In contrast, graft-versus-leukemia effects were not abrogated, as RAPA-treated T cells had increased resistance to apoptosis and retained their effector function and proliferative capacity upon re-stimulation. Importantly, we found that RAPA impact on Treg and CD8⁺ T cells was closely dependent upon IL-2 signaling and that therapeutic options interfering with IL-2, such as calcineurin inhibitors, antagonize the IL-2-dependent promotion of Treg mediated by RAPA. Our results suggest that RAPA immunological efficacy could be improved in combination with drugs having possible synergistic effects such as the hypomethylating agent 5-azacytidine.     

Reconstructing immunity after allogeneic transplantation

Immunologic Research - A major goal of our research is to reduce the graft-vs-host disease (GVHD) activity of allogeneic donor T cells in bone marrow transplantation (BMT), while preserving...