Targeting dendritic cells for selective modulation of GVHD

靶向树突状细胞选择性调节 GVHD

• 批准号: 8349468
• 负责人: Terry Fry
• 金额: $ 24.89万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8349468
• 关键词: Allogenic; Antibodies; Antigen Targeting; Antigen-Presenting Cells; Antigens; B-Lymphocytes; Biological Preservation; Blood; Bone Marrow; Bone Marrow Transplantation; CD19 gene; Cells; Characteristics; Clinic; Competence; Complication; Dendritic Cells; Development; Diabetes Mellitus; Disease Resistance; Donor Lymphocyte Infusion; Drug usage; Frequencies; Functional disorder; Genes; Goals; ITGAX gene; Immune; Immune response; Immune system; Immunologic Deficiency Syndromes; Immunologics; Immunosuppression; Immunosuppressive Agents; Immunotherapeutic agent; Infection; Interferon Type II; Interleukin-10; Laboratories; Malignant Neoplasms; Mediating; Modality; Modeling; Monoclonal Antibodies; Morbidity - disease rate; Mouse Strains; Muramidase; Mus; Myeloid Cells; Organ; Pathway interactions; Patients; Phagocytes; Pharmaceutical Preparations; Phenotype; Photopheresis; Play; Population; Population Biology; Production; Protocols documentation; Publishing; Reaction; Regimen; Relapse; Reporting; Risk; Role; S100A8 gene; S100A9 gene; STAT1 gene; Severities; Severity of illness; Signal Transduction; Staging; Systemic Therapy; T cell response; T-Cell Depletion; T-Lymphocyte; Tissues; Translating; Treatment Efficacy; Tumor Antigens; Vaccination; Vaccines; Withdrawal; Work; base; cancer cell; cytokine; exenatide; graft vs host disease; graft vs leukemia effect; in vitro testing; in vivo; inflammatory modulation; inhibitor/antagonist; interferon gamma receptor; interferon gamma receptors; leukemia; mortality; novel; pathogen; prevent; promoter; recombinase; reconstitution; research study; response; transcription factor; tumor

The experiments conducted under aim 1 have demonstrated that even relatively mild GVHD can diminish quantitative T cell immune responses to vaccination and functional immune responses to tumors expressing vaccine-targeted antigens. This work has been published (Capitini et al, Blood, 2009) and demonstrated the importance of preventing GVHD if BMT is to be optimized as a platform for immunotherapeutic approaches targeting malignancy. Under aim 2, we have established that inhibition of interferon gamma signaling can prevent the development of GVHD (Capitini et al, Blood 2009). Reduction in GVHD severity with disruption of interferon gamma signaling on T cells was not surprising given the known importance of this cytokine in GVHD but this approach results in immunodeficiency. The novel finding in these studies was that selective loss of interferon gamma receptor on bone marrow-derived non-T cells also prevented GVHD mediated by T cells with intact interferon gamma signaling and did so with preservation of qualitative and functional responses to vaccines. We have also established the extracorporeal photopheresis, a modality currently being used in the clinic to treat GVHD, also prevented GVHD with preserved vaccine response via modulation of IL-10 production in DC populations (Capitini et al, Biology of Blood and Marrow Transplantation, 2011). We next studied whether other components of the interferon gamma pathway could be targeted in donor bone marrow to prevent GVHD. Using bone marrow deficient in STAT1, a transcription factor necessary for interferon gamma signaling, we have confirmed that interference with this pathway in bone marrow-derived cells can prevent GVHD with preserved immune competence. To identify the relevant bone-marrow-derived cell population, we have selectively targeted STAT1 by generating mice with a floxed STAT1 gene (obtained from Dr. Lothar Hennighausen) that express the Cre recombinase under non-T cell promoters (CD11c (DC expression), lysozyme (on all phagocytic cells), and CD19 (B cell expression). In recipients of bone marrow from these donors, the STAT1 gene (and, thus, interferon gamma signaling) can be ablated in selective cell populations. Selective loss of STAT1 in all of these cell populations was not sufficient to prevent GVHD. Interestingly, further assessment of DC reconstitution in recipients of allogeneic STAT1 deficient bone marrow demonstrated expanded plasmacytoid DC (pDC) populations. Further more, we have confirmed that STAT1 remained intact in all of the Cre floxed STAT1 mouse strains generated thus far. We have obtained pDC-depleting antibodies (from Dr. Giorgio Trinchieri) to confirm that the expanded pDC populations are responsible for the GVHD protection observed in recipients of STAT1-deficinet bone marrow. Preliminary studies indicate that this is case. Based on these findings we have begun to analyze the characteristics of the expanded pDCs mediating GVHD resistance. Preliminary studies indicate that there is an increase in the frequency of CD9 negative pDCs, reported to be tolerogenic. In addition, expression of S100A8 and S100A9, genes associated with a suppressive phenotype in myeloid cells, is increased in pDCs from STAT1 deficient bone marrow recipients. Using S100A8/S100A9 deficient mice (obtained from Dr. Dimitri Gabrilovich through the Mackall laboratory) we have confirmed that loss of these genes in donor bone marrow increases the severity of GVHD. Aim 3 is in the initial stage. We have obtained selective Stat1 inhibitors and are beginning to test these in vitro. In addition, we used off-target inhibition of STAT1 by exenatide, a drug used in patients with diabetes, to demonstrate reduction of GVHD severity in our murine models.

根据目标 1 进行的实验表明，即使是相对轻微的 GVHD 也可以减少对疫苗接种的定量 T 细胞免疫反应以及对表达疫苗靶向抗原的肿瘤的功能性免疫反应。这项工作已发表（Capitini 等人，Blood，2009），并证明了如果要将 BMT 优化为针对恶性肿瘤的免疫治疗方法的平台，则预防 GVHD 的重要性。 根据目标 2，我们已经确定抑制干扰素 γ 信号传导可以预防 GVHD 的发生（Capitini 等人，Blood 2009）。鉴于已知干扰素γ在 GVHD 中的重要性，通过破坏 T 细胞上的干扰素 γ 信号传导来降低 GVHD 严重程度并不令人意外，但这种方法会导致免疫缺陷。这些研究的新发现是，骨髓来源的非 T 细胞上干扰素 γ 受体的选择性丧失也可以阻止具有完整干扰素 γ 信号传导的 T 细胞介导的 GVHD，并保留对疫苗的定性和功能反应。我们还建立了体外光采术，这是一种目前在临床上用于治疗 GVHD 的方法，也通过调节 DC 群体中 IL-10 的产生来预防 GVHD，同时保留疫苗反应（Capitini 等人，Biology of Blood and Marrow Transplantation，2011）。接下来我们研究了干扰素γ途径的其他成分是否可以靶向供体骨髓以预防GVHD。利用缺乏 STAT1（干扰素 γ 信号转导必需的转录因子）的骨髓，我们已经证实，干扰骨髓来源细胞中的这一通路可以预防 GVHD，同时保留免疫能力。为了鉴定相关的骨髓来源细胞群，我们通过生成具有 floxed STAT1 基因（从 Lothar Hennighausen 博士获得）的小鼠来选择性地靶向 STAT1，这些小鼠在非 T 细胞启动子（CD11c（DC 表达）、溶菌酶（在所有吞噬细胞上）和 CD19（B 细胞表达）下表达 Cre 重组酶。在来自这些捐赠者的骨髓的接受者中， STAT1 基因（以及干扰素γ信号传导）可以在选择性细胞群中被消除。所有这些细胞群中 STAT1 的选择性缺失不足以预防 GVHD。有趣的是，对同种异体 STAT1 缺陷骨髓受体的 DC 重建的进一步评估表明，浆细胞样 DC (pDC) 群体有所扩大。此外，我们已经确认 STAT1 在所有 迄今为止生成的 Cre floxed STAT1 小鼠品系。我们已经获得了 pDC 消耗抗体（来自 Giorgio Trinchieri 博士），以确认扩大的 pDC 群体是在 STAT1 缺陷骨髓受者中观察到的 GVHD 保护的原因。初步研究表明情况确实如此。基于这些发现，我们开始分析扩增的 pDC 的特征 介导 GVHD 抵抗。初步研究表明，据报告具有耐受性的 CD9 阴性 pDC 的频率有所增加。此外，S100A8和S100A9（与骨髓细胞抑制表型相关的基因）的表达在来自STAT1缺陷的骨髓受体的pDC中增加。使用 S100A8/S100A9 缺陷小鼠（从 Dr. Dimitri Gabrilovich（通过 Mackall 实验室）我们已经证实，供体骨髓中这些基因的丢失会增加 GVHD 的严重程度。 目标3正处于初始阶段。我们已经获得了选择性 Stat1 抑制剂，并开始对其进行体外测试。此外，我们使用艾塞那肽（一种用于糖尿病患者的药物）对 STAT1 的脱靶抑制来证明 GVHD 的降低 我们的小鼠模型中的严重程度。