Regulatory monocytes in CNS autoimmune disease

描述（由申请人提供）：醋酸格拉替默（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）相关。研究表明，GA还对抗原（Ag）呈递细胞（APC）发挥免疫调节活性，使其分泌抗炎的“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细胞活化。GA处理小鼠促进“II型”单核细胞的发育，其特征是IL-10和TGF-¿分泌增加，TNF和IL-12分泌减少，STAT1信号传导减少。II型单核细胞促进na - ve T （Th0）细胞分化为Th2和FoxP3+ Treg，不依赖于Ag特异性。II型单核细胞诱导的调节性T细胞的过继转移特异性针对非自身Ag改善的EAE，表明与髓磷脂Ag的交叉反应性，被认为是T细胞介导的GA免疫调节的先决条件，不是必需的。将II型单核细胞过继移植到EAE小鼠体内，可逆转瘫痪，抑制Th17细胞发育，促进Th2分化和Treg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模式，即调节性单核细胞的过继转移，如何用于体内研究APC-T细胞的相互作用。我们建议研究GA处理下单核细胞II型分化的途径，并表征II型单核细胞如何在体内诱导Th2细胞和Treg。我们假设，除了STAT1，其他信号通路，特别是STAT3和NF-？B，可能在II型单核细胞中发生改变。我们假设，II型单核细胞表达TGF-2对于这些细胞在体内诱导调节性T细胞是必要的。具体而言，我们建议：(1)评估II型单核细胞在体内的特性，并表征其诱导Treg和Th2细胞的需求。我们将确定II型单核细胞的存活以及它们在受体小鼠中诱导免疫调节的能力保持多久。通过过继转移缺乏il -10或缺乏TGF-¿-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天然Treg细胞。(2)分子途径(如NF-？B和MAPK)可能参与II型单核细胞分化将被检查。(3)在小鼠研究的同时，我们将评估开始GA治疗的MS患者中II型单核细胞的发育，并研究这些患者中可能发育的II型单核细胞是否参与调节性T细胞的诱导。我们提出的研究与MS治疗高度相关，因为它们可能为开发可能比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见解。

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.