Regulatory monocytes in CNS autoimmune disease

描述(由申请人提供)：用醋酸格来特雷(GA，共聚物-1，Copaxone(R))治疗多发性硬化症(MS)患者与诱导GA反应性Th2和CD4+CD25+调节性T细胞(Treg)有关。研究表明，GA还对抗原(Ag)提呈细胞(APC)发挥免疫调节作用，使它们分泌抗炎的“II型”细胞因子。我们研究了GA处理如何改变单核细胞活性，以及这些APC如何影响T细胞激活。赤霉素A处理小鼠可促进“II型”单核细胞的发育，表现为IL-10和TGF-β的分泌增加，TNF和IL-12的分泌减少，STAT1信号转导减少。II型单核细胞可促进T细胞分化为Th2和FoxP3+Treg，而不依赖于抗原的特异性。过继转移II型单核细胞诱导的针对非自身抗原的调节性T细胞可改善EAE，表明与髓鞘抗原的交叉反应是GA介导T细胞免疫调节的先决条件，不是必需的。过继将II型单核细胞转移到EAE小鼠体内可逆转瘫痪，抑制Th17细胞的发育，促进Th2分化和Treg的扩增。这些发现表明，APC是GA介导的免疫调节的主要靶点。我们还建立了这种新的范式，即调节性单核细胞的过继转移，可以用于研究APC-T细胞在体内的相互作用。我们建议研究GA诱导单核细胞分化为II型的途径(S)，并在体内研究II型单核细胞如何诱导Th2型细胞和Treg。我们推测，在II型单核细胞中，除了STAT1外，其他信号通路，特别是STAT3和NF-βB也可能发生改变。我们推测，II型单核细胞表达转化生长因子-2是这些细胞在体内诱导调节性T细胞所必需的。具体地说，我们建议：(1)评估体内II型单核细胞的特性，并表征它们诱导Treg和Th2细胞的需求。我们将确定II型单核细胞的存活率，以及它们在受体小鼠中保持多久诱导免疫调节的能力。通过过继转移缺乏IL-10或缺乏转化生长因子的“II型单核细胞”，我们将确定这些细胞因子对单核细胞诱导调节性T细胞的相对贡献。我们将评估II型单核细胞是否诱导适应性或自然Treg细胞。(2)对可能参与II型单核细胞分化的分子途径(如核因子-β和MAPK)进行研究。(3)在我们的小鼠研究的同时，我们将评估启动GA治疗的MS患者的II型单核细胞发育，并探讨这些患者的II型单核细胞是否可能参与调节性T细胞的诱导。我们建议的研究与MS治疗高度相关，因为它们可能为开发比GA更有效地促进II型APC分化和T细胞免疫调节的试剂提供洞察力。与公共卫生相关：最近的研究表明，已被批准用于多发性硬化症(MS)的治疗方法--醋酸格列塔美酯(GA，Copolmer-1，Copaxone(R))可诱导负责T细胞免疫调节的抗炎“II型”抗原提呈细胞(APC)，这使人们对GA在多发性硬化症治疗中的作用有了新的理解。在这项研究计划中，我们将阐明在小鼠和GA治疗的患者中诱导II型抗炎单核细胞的机制，并确定这些调节性APC如何影响T细胞调节。这些研究应该有助于开发比GA更有效地促进II型APC分化和T细胞免疫调节的试剂。

DESCRIPTION (provided by applicant): Treatment of multiple sclerosis (MS) patients with glatiramer acetate (GA, Copolymer-1, Copaxone(r)) has been associated with induction of GA-reactive Th2 and CD4+CD25+ regulatory T cells (Treg). Research indicates that GA also exerts immunomodulatory activity on antigen (Ag) presenting cells (APC), causing them to secrete an anti-inflammatory "type II" cytokines. We investigated how GA treatment alters monocyte activity and how these APC influence T cell activation. GA treatment of mice promoted development of "type II" monocytes, which were characterized by increased secretion of IL-10 and TGF-¿, reduced secretion of TNF and IL-12, and reduced STAT1 signaling. Type II monocytes promoted differentiation of na¿ve T (Th0) cells into Th2 and FoxP3+ Treg independent of Ag specificity. Adoptive transfer of type II monocyte-induced regulatory T cells specific for a non-self Ag ameliorated EAE, indicating that cross-reactivity with myelin Ag, considered a prerequisite for T cell-mediated immune modulation by GA, is not required. Adoptive transfer of type II monocytes into mice with EAE reversed paralysis, suppressed Th17 cell development and promoted both Th2 differentiation and expansion of Treg. These findings indicate that APC are a primary target for GA- mediated immune modulation. We have also established how this novel paradigm, adoptive transfer of regulatory monocytes, can be used to study APC-T cell interaction in vivo. We propose to investigate the pathway(s) involved in type II differentiation of monocytes by GA treatment and to characterize how type II monocytes lead to induction of Th2 cells and Treg in vivo. We hypothesize that, in addition to STAT1, other signaling pathways, in particular STAT3 and NF-?B, may be altered in type II monocytes. We hypothesize that expression of TGF-2 by type II monocytes is necessary for these cells to induce regulatory T cells in vivo. Specifically, we propose, (1) to evaluate properties of type II monocytes in vivo and characterize their requirements for induction of Treg and Th2 cells. We will determine type II monocytes survival and how long they retain their capability to induce immune modulation in recipient mice. By adoptive transfer of IL-10-deficient or TGF-¿-deficient "type II monocytes" we will establish the relative contribution of these cytokines for induction of regulatory T cells by monocytes. We will evaluate whether type II monocytes induce adaptive or natural Treg cells. (2) Molecular pathways (e.g. NF-?B and MAPK) that may be involved in type II monocyte differentiation will be examined. (3) In parallel with our murine studies, we will evaluate type II monocyte development in MS patients that initiate GA treatment and address whether type II monocytes 5hat may develop in these patients participate in the induction of regulatory T cells. Our proposed studies are highly relevant to MS therapy as they may provide insight leading to the development of reagents that may promote type II APC differentiation and T cell immune modulation more effectively than GA. PUBLIC HEALTH RELEVANCE: Recent research has demonstrated that glatiramer acetate (GA, Copolymer-1, Copaxone(r)), an approved therapy for multiple sclerosis (MS), induces anti-inflammatory "type II" antigen presenting cells (APC) that are responsible for T cell immune modulation, providing a new understanding how GA functions in MS treatment. In this research program, we will elucidate the mechanisms responsible for induction of type II anti-inflammatory monocytes in mice and in GA-treated patients and determine how these regulatory APC influence T cell regulation. These studies should provide insight leading to the development of reagents that may promote type II APC differentiation and T cell immune modulation more effectively than GA.