Implication of HUCBC: a novel therapeutic strategy for Alzheimer's disease

描述（由申请人提供）：人脐带血细胞（HUCBC）是众所周知的特异性免疫调节剂，可平衡（即无完全免疫抑制、GVHD或排斥反应）外周和中枢免疫应答的改变。其他研究者已经证明它们促进成人骨髓（BM）祖细胞的动员。此外，我们最近证明，来自HUCBC输注PSAPP小鼠的血清显着抑制IFN-γ诱导的小胶质细胞CD 40表达？并显著增加了小胶质细胞A？吞噬活性，而没有不可接受的免疫损害。在确认中，这种作用被CD 40与CD 40 L蛋白的连接所抑制。重要的是，来自这些HUCBC输注小鼠的原代成年小胶质细胞也显示出增加的A？吞噬活性和强的A？IgG滴度。总之，这些数据表明，由HUCBC诱导的CD 40信号转导抑制和A？IgG产生增强介导的先天性和体液免疫微环境的平衡改变。与神经毒性先天性反应的下调和有益的体液反应的上调雅阁，A-淀粉样蛋白沉积和脑淀粉样血管病（CAA;对血管淀粉样蛋白沉积的炎症反应）在体内通过HUCBC输注减少，伴随着：（a）增加血清A？1-40，42，表明从CNS流出（B）降低可溶性CD 40 L血清水平，（c）降低小胶质细胞CD 40表达，最后，（d）CNS/血清抗炎（IL-10和TGF-21）水平升高，促炎细胞因子（IL-1和TNF-α）降低。最后，我们的初步数据表明，与对照原代BM来源的单核细胞/巨噬细胞（MO/X）相比，来自HUCBC输注的PSAPP小鼠的MO/X显示出增强的A？吞噬活性。这些数据沿着我们先前的发现，即将Tg 2576小鼠与CD 40 L缺失小鼠杂交或用CD 40 L抗体治疗PSAPP小鼠降低了A？负荷，使我们假设HUCBC输注可减轻A？/？。- 阿尔茨海默病（AD）小鼠中的淀粉样蛋白病理学，其通过由CD 40-CD 40 L破坏介导的先天和体液免疫的改变导致BM衍生的祖细胞MO/X的动员，增加抗炎细胞因子的产生，并增加大脑中淀粉样蛋白的清除。在这里，我们建议通过研究输注HUCBC的PSAPP小鼠中的CD 40信号转导来检验HUCBC介导的CD 40-CD 40 L相互作用的抑制减少淀粉样变性的假设。基于我们的初步数据，我们还计划通过单独和联合给予IL- 10、TGF-β 1和NGF-β来重建HUCBC输注的效果;我们发现这些关键因素对于HUCBC调节CD 40活性和淀粉样变性的能力是必不可少的，而不需要全身性免疫抑制、排斥反应或GVHD。此外，我们将测试HUCBC输注动员BM衍生的MO/X，导致转分化为巨噬细胞，巨噬细胞进入CNS并进一步分化为具有增强的A？吞噬能力的小胶质细胞的假设。我们的长期目标是将这种联合治疗纳入轻度至中度AD患者的I期人体试验。公共卫生相关性：在过去的几年中，我们已经表明，通过CD 40-CD 40 L系统的信号中断减少了APP（淀粉样前体蛋白）过度产生转基因小鼠大脑中的淀粉样蛋白沉积，同时改善认知缺陷。CD 40阻断通过减缓活化的小胶质细胞的成熟而起作用，从而维持吞噬细胞表型，同时降低CNS中潜在神经毒性细胞因子（IL-10和TNF-21）的产生，并增加治疗性抗炎细胞因子（IL-10和TGF-21）的产生。最重要的是，我们证明了这种吞噬小胶质细胞表型增强了淀粉样蛋白斑块从脑实质中的清除。不幸的是，CD 40阻断伴随着不可接受的免疫耗竭副作用，这使得该策略对于转移到临床环境不是最佳的。人脐带血细胞（HUCBC）是众所周知的特异性免疫调节剂，其赋予外周和中枢、先天和体液免疫应答的平衡改变而没有排斥或全身免疫抑制。作为支持，我们的初步数据显示，来自HUCBC输注小鼠的外周抗原呈递细胞（APC）中的CD 40表达及其信号传导功能不受影响，而CNS中的APC经历了吞噬活性增加、毒性细胞因子下调和抗炎细胞因子产生增加。因此，本申请提出通过研究输注HUCBC的PSAPP小鼠中的CD 40信号传导来研究HUCBC介导的CD 40-CD 40 L相互作用的抑制减少淀粉样变性的假设。此外，我们计划研究可溶性因子，包括IL-10，TGF-β 1和NGF-β（这些因子在输注HUCBC的小鼠中显著升高），它们调节CD 40-CD 40 L相互作用并降低淀粉样蛋白实质负荷，长期目标是开发用于人体试验的联合治疗。最后，将确定HUCBC输注到PSAPP小鼠中后骨髓来源的MO/X的贡献。总之，预期的结果将表明，HUCBC或HUCBC诱导的分离的可溶性因子将是AD的新的治疗策略。

DESCRIPTION (provided by applicant): Human umbilical cord blood cells (HUCBC) are well known specific immunomodutators that confer a balanced (i.e. without complete immunosuppression, GVHD, or rejection) alteration of both peripheral and central immune responses. Other investigators have demonstrated they promote mobilization of adult bone marrow (BM) progenitor cells. In addition we recently demonstrated sera derived from HUCBC-infused PSAPP mice significantly inhibited microglial CD40 expression induced by IFN-? and markedly increased microglial A¿ phagocytic activity without unacceptable immune compromise. In confirmation, this effect was inhibited by the ligation of CD40 with CD40L protein. Importantly, primary adult microglia from these HUCBC-infused mice also showed increased A¿ phagocytic activity, and a strong A¿ IgG titer. Together these data suggest a balanced alteration of both innate and humoral immune microenvironments mediated by an HUCBC induced suppression of CD40 signaling and enhancement of A¿ IgG production. In accord with this downregulation of neurotoxic innate responses and upregulation of salutary humoral responses, A¿ levels/¿- amyloid deposits and cerebral amyloid angiopathy (CAA; an inflammatory response to vascular amyloid deposits) are reduced by HUCBC infusion in vivo, with attendant: (a) increased serum levels of A¿1-40, 42, suggesting efflux from the CNS (b) decreased soluble CD40L serum levels, (c) decreased microglial CD40 expression, and finally, (d) elevated CNS/serum levels of anti-inflammatory (IL-10 and TGF-21) with decrease pro-inflammatory cytokines (IL-1¿ and TNF-a). Finally, our preliminary data suggests that, compared with control primary BM derived monocytes/macrophages (MO/X), MO/X from HUCBC-infused PSAPP mice show enhanced A¿ phagocytic activity. These data along with our previous findings that crossing Tg2576 mice with CD40L null mice or treating PSAPP mice with CD40L antibody reduced A¿ loads, lead us to hypothesize that HUCBC infusion confers a mitigation of A¿/¿-amyloid pathology in Alzheimer's disease (AD) mice by alterations in innate and humoral immunity mediated by CD40-CD40L disruption resulting in mobilization of BM-derived progenitor MO/X, increased anti-inflammatory cytokine production, and increased amyloid clearance from the brain. Here we propose to test the hypothesis that HUCBC mediated dampening of the CD40-CD40L interaction reduces amyloidosis by investigating CD40 signaling in HUCBC infused PSAPP mice. Based on our preliminary data, we additionally plan to reconstitute the effects of HUCBC infusion by administering IL- 10, TGF-¿1 and NGF-¿ alone and in combinations; key factors we found to be essential for HUCBC ability to modulate CD40 activity and amyloidosis without systemic immunosuppression, rejection, or GVHD. Also, we will test the hypothesis that HUCBC infusion mobilizes BM-derived MO/X, leading to transdifferentiation into macrophages which enter the CNS and further differentiate into microglia with enhanced A¿ phagocytic capacity. It is our long-term goal to move this combination treatment into phase I human trials for patients with mild to moderate AD. PUBLIC HEALTH RELEVANCE: In the past years, we have shown that disruption of signaling through the CD40-CD40L system reduces amyloid deposition in the brains of APP (amyloid precursor protein) overproducing transgenic mice while ameliorating cognitive deficits. The CD40 blockade acts by slowing maturation of activated microglia thereby maintaining a phagocytic phenotype with concurrent decreased production of potentially neurotoxic cytokines (IL-¿2 and TNF-¿), and increased production of therapeutic anti-inflammatory cytokines (IL-10 and TGF-21) in the CNS. Most importantly this we demonstrated this phagocytic microglial phenotype enhances clearance of amyloid plaques from the brain parenchyma. Unfortunately CD40 blockade carries with it unacceptable immune-depleting side effects which makes this strategy less than optimal for transfer to the clinical setting. Human umbilical cord blood cells (HUCBC) are well known specific immunomodutators that confer a balanced alteration of peripheral and central, innate and humoral immune responses without rejection or systemic immunosuppression. In support, our preliminary data showed that CD40 expression and its signaling functions in peripheral antigen presenting cells (APCs) from HUCBC-infused mice are not affected, while those in the CNS experience increased phagocytic activity, down regulation of toxic cytokines, and increased generation of anti-inflammatory cytokines. Thus, this application proposes to investigate the hypothesis that HUCBC mediated dampening of the CD40-CD40L interaction reduces amyloidosis by investigating CD40 signaling in HUCBC infused PSAPP mice. Furthermore, we plan to investigate the soluble factors, including IL-10, TGF-¿1 and NGF-¿ (these factors significantly elevated in HUCBC-infused mice), which modulate the CD40-CD40L interaction and reduced amyloid parenchymal load in this context with the long term goal of developing a combination treatment for use in human trials. Finally, the contribution of bone marrow-derived MO/X after HUCBC infusion into PSAPP mice will be determined. In summary, the expected results will suggest that HUCBC or, isolated soluble factors that HUCBC induce, would be a novel therapeutic strategy for AD.