Matrix metalloproteinase-2 modulates inflammation via TLR2

描述（由申请人提供）：免疫疗法在治疗转移性癌症方面取得了一些成功。然而，尽管肿瘤内抗原特异性T细胞积累，但大多数患者的持久效果有限。肿瘤微环境（TME）通过主动阻断局部抗肿瘤免疫反应和促进免疫逃逸，在一定程度上负责这些失败。几种免疫调节因子和/或细胞在TME中被激发，包括金属蛋白酶，它们通过对肿瘤基质、脉管系统的影响和TGF和TNF等因子的激活来促进肿瘤的生长和侵袭。基质金属蛋白酶-2 （MMP-2）是一种明胶酶，在包括黑色素瘤在内的大多数癌症中过表达，其表达与传播增加和较差的生存/预后相关。我们最近发现酶活性的mmp -2条件树突状细胞（dc）通过抑制IL-12和上调OX40L表达的机制优先产生TH2细胞。值得注意的是，只有酶活性的MMP-2才能阻断IL-12的产生，而活性和非活性的MMP-2构象都能诱导OX40L的上调。引人注目的是，我们还在一些表现出mmp -2特异性反应的患者中检测到TILs。这些反应是th2样的，它们的存在被发现与生存率呈负相关。因此，MMP-2同时作为内源性TH2“调节剂”和肿瘤相关抗原，这可能在一定程度上解释了黑色素瘤中TH2不良反应的发生。我们之前描述了IL-12抑制的机制，这涉及到IIFN型受体的酶切，从而降低STAT-1磷酸化和IL-12p35转录。我们已经确定了MMP-2在dc和TME中失调的其他新的免疫机制：MMP-2直接触发dc和黑色素瘤细胞系中TLR-2介导的信号传导，分别诱导OX40L的表达和促炎细胞因子的产生。因此，在Aim1中，我们将首先确定与OX40L上调相关的TLR受体和信号通路。这一新发现的临床意义将在黑色素瘤的动物模型中进行测试（目的2）。最后，在Aim 3中，我们将评估MMP-2是否通过tlr介导的途径直接调节黑色素瘤的功能和生长。

DESCRIPTION (provided by applicant): Immune therapies have had some success in the treatment of metastatic cancers. However, durable effects are limited in most patients despite the accumulation of intra-tumoral antigen-specific T cells. The tumor microenvironment (TME) is partly responsible for these failures through active blockade of local antitumor immune responses and facilitation of immune escape. Several immune modulating factors and/or cells are elicited within the TME, including the metalloproteinases, which enhance tumor growth and invasion through effects upon the tumor stroma, vasculature, and activation of factors such as TGF¿ and TNF¿. Matrix metalloproteinase-2 (MMP-2), a gelatinase, is over-expressed in most cancers including melanoma, and its expression is associated with increased dissemination and poorer survival/prognosis. We recently found that enzymatically active MMP-2-conditioned dendritic cells (DCs) preferentially generate TH2 cells through mechanisms that inhibit IL-12 and up-regulate OX40L expression. Of note, only enzymatically active MMP-2 blocks IL-12 production, while both active and inactive conformations of MMP-2 induce up-regulation of OX40L. Strikingly, we also detected TILs in several patients that displayed MMP-2-specific responses. These responses were TH2-like and their presence was found to be inversely correlated with survival. MMP-2, therefore, acts simultaneously as an endogenous TH2 "conditioner" and tumor-associated antigen, which may explain, in part, the occurrence of unfavorable TH2 responses in melanoma. We previously characterized the mechanism responsible for IL-12 inhibition, which involves enzymatic cleavage of the type IIFN receptor, and consequent reduced STAT-1 phosphorylation and IL-12p35 transcription. We have since identified other novel immune mechanisms underlying MMP-2-dysregulation of DCs and the TME: MMP-2 directly triggers TLR-2 mediated signaling on both DCs and melanoma cell lines, inducing expression of OX40L and production of pro-inflammatory cytokines, respectively. In Aim1, therefore, we will first identify the relevant TLR receptors and signaling pathways involved in OX40L up-regulation. The clinical relevance of this novel finding will be tested in animal models of melanoma (Aim 2). Finally, in Aim 3, we will evaluate whether MMP-2 directly modulates melanoma function and growth via TLR-mediated pathways.