Co-activation of macrophages and T cells contribute to chronic GVHD in human IL-6 transgenic humanised mouse model.

BACKGROUND: Graft-versus host disease (GVHD) is a complication of stem cell transplantation associated with significant morbidity and mortality. Non-specific immune-suppression, the mainstay of treatment, may result in immune-surveillance dysfunction and disease recurrence. METHODS: We created humanised mice model for chronic GVHD (cGVHD) by injecting cord blood (CB)-derived human CD34 FINDINGS: In cGVHD humanised mice, we found activation of T cells in the spleen, lung, liver, and skin, activation of macrophages in lung and liver, and loss of appendages in skin, obstruction of bronchioles in lung and portal fibrosis in liver recapitulating cGVHD. Acute GVHD humanised mice showed activation of T cells with skewed TCR repertoire without significant macrophage activation. INTERPRETATION: Using humanised mouse models, we demonstrated distinct immune mechanisms contributing acute and chronic GVHD. In cGVHD model, co-activation of human HSPC-derived macrophages and T cells educated in the recipient thymus contributed to delayed onset, multi-organ disease. In acute GVHD model, mature human T cells contained in the graft resulted in rapid disease progression. These humanised mouse models may facilitate future development of new molecular medicine targeting GVHD

HLA ClassⅠ 遺伝子導入NOD/SCID/IL-2RgKO（HLA ClassⅠTgNSG）マウスを用いた 異種移植モデルによるWT1抗原に対するヒト免疫応答の評価

Final publication is available at http://www.bloodjournal.org/京都大学0048新制・課程博士博士(医学)甲第19614号医博第4121号新制||医||1015(附属図書館)32650京都大学大学院医学研究科医学専攻(主査)教授 髙折 晃史, 教授 山田 亮, 教授 三森 経世学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDFA

Generation of functional human T-cell subsets with HLA-restricted immune responses in HLA class I expressing NOD/SCID/IL2rγnull humanized mice

Whereas humanized mouse models have contributed significantly to human immunology research, human T cells developing in mouse thymic environment fail to demonstrate HLA-restricted function. To achieve HLA-restricted human immune response, we created an immune-compromised non-obese diabetic/SCID/IL2rgnull strain (NSG) with homozygous expression of HLA class I heavy chain and light chain (NSG-HLA-A2/HHD). Transplantation of purified Lin−CD34+CD38− human hematopoietic stem cells into NSG-HLA-A2/HHD newborns resulted in the development of human CD4+ and CD8+ TCRαβ+ T cells and CD4−CD8− and CD8+ TCRγδ+ cells in recipient bone marrow and spleen. Human cytotoxic T lymphocytes (CTLs) become functionally mature, as evidenced by the production of granzyme corresponding to phenotypic transition from naïve to effector memory CTLs. In these recipients, human Th17 cells developed along with Th1 and Th2 cells. Epstein–Barr virus (EBV) infection in the humanized NSG-HLA-A2/HHD recipients resulted in the formation of lymphoproliferative lesions consisting mainly of human B cells with scattered human T cells. Human CTLs developing in the recipients recognized EBV-derived peptides in an HLA-restricted manner and exerted HLA-restricted cytotoxicity against EBV-infected human B cells. The HLA-expressing humanized mouse with functional HLA-restricted T cells and consistent representation of rare T-cell subsets overcomes a major constraint in human immunology, and serves as a useful model for investigation of human immune responses against pathogens and for the development of therapeutic strategies against human diseases

Induction of WT1-specific human CD8+ T cells from human HSCs in HLA class I Tg NOD/SCID/IL2rgKO mice.

Induction of specific immune response against therapy-resistant tumor cells can potentially improve clinical outcomes in malignancies. To optimize immunotherapy in the clinic, we aimed to create an in vivo model enabling us to analyze human cytotoxic T-lymphocyte (CTL) responses against human malignancies. To this end, we developed NOD/SCID/IL2rgKO (NSG) mice expressing the HLA class I molecules HLA-A*0201 and A*2402. In the bone marrow (BM) and spleen of HLA class I transgenic (Tg) NSG mice transplanted with cord blood hematopoietic stem cells (HSCs), we found human memory CD8(+) T cells and antigen-presenting cells. To evaluate antigen-specific human CTL responses, we immunized HLA class I Tg NSG mice using polyinosinic:polycytidylic acid mixed Wilms tumor 1 (WT1) peptides, with or without WT1 peptide-loaded autologous dendritic cells. After immunization, the frequencies of HLA-restricted WT1-specific CTLs increased significantly in the spleen. Next, we transplanted the WT1-specific T-cell receptor (WT1-TCR) gene-transduced human HSCs into HLA class I Tg NSG newborn mice. WT1 tetramer-positive CD8(+) T cells differentiated from WT1-TCR-transduced HSCs in the recipients\u27 BM, spleen, and thymus. Upon stimulation with WT1 peptide in vitro, these CTLs produced interferon-γ and showed lytic activity against leukemia cells in an antigen-specific, HLA-restricted manner. HLA class I Tg NSG xenografts may serve as a preclinical model to develop effective immunotherapy against human malignancies. Blood 2016 Feb 11; 127(6):722-34

Central nervous system infection following allogeneic hematopoietic stem cell transplantation

Objective/background: Here, we described the clinical characteristics and outcomes of central nervous system (CNS) infections occurring after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a single institution over the previous 6 years. Methods: Charts of 353 consecutive allogeneic transplant recipients were retrospectively reviewed for CNS infection. Results: A total of 17 cases of CNS infection were identified at a median of 38 days (range, 10–1028 days) after allo-HSCT. Causative pathogens were human herpesvirus-6 (n = 6), enterococcus (n = 2), staphylococcus (n = 2), streptococcus (n = 2), varicella zoster virus (n = 1), cytomegalovirus (n = 1), John Cunningham virus (n = 1), adenovirus (n = 1), and Toxoplasma gondii (n = 1). The cumulative incidence of CNS infection was 4.1% at 1 year and 5.5% at 5 years. Conclusion: Multivariate analysis revealed that high-risk disease status was a risk factor for developing CNS infection (p = .02), and that overall survival at 3 years after allo-HSCT was 33% in patients with CNS infection and 53% in those without CNS infection (p = .04). Keywords: Allogeneic hematopoietic stem cell transplantation, Central nervous system infections, Human herpesvirus