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细胞的积累，但在大多数患者中的持久效果是有限的。肿瘤微环境（TME）通过主动阻断局部抗肿瘤免疫应答和促进免疫逃逸，部分负责这些失败。在TME内引发几种免疫调节因子和/或细胞，包括金属蛋白酶，其通过对肿瘤基质、脉管系统的作用以及诸如TGF β和TNF β的因子的活化来增强肿瘤生长和侵袭。 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度表达，其表达与播散增加和生存/预后较差相关。我们最近发现，酶活性MMP-2条件树突状细胞（DC）优先产生TH 2细胞通过抑制IL-12和上调OX 40 L表达的机制。值得注意的是，只有酶活性MMP-2阻断IL-12的产生，而MMP-2的活性和非活性构象都诱导OX 40 L的上调。引人注目的是，我们还在几个显示MMP-2特异性反应的患者中检测到TILs。这些反应是TH 2样的，并且发现它们的存在与存活率呈负相关。因此，MMP-2同时作为内源性TH 2“调节剂”和肿瘤相关抗原，这可以部分解释黑色素瘤中不利的TH 2应答的发生。我们先前表征了负责IL-12抑制的机制，其涉及IIFN型受体的酶促裂解，以及随后降低的STAT-1磷酸化和IL-12 p35转录。此后，我们已经确定了其他新的免疫机制，这些机制是MMP-2-DCs和TME失调的基础：MMP-2直接触发DCs和黑素瘤细胞系上TLR-2介导的信号传导，分别诱导OX 40 L的表达和促炎细胞因子的产生。因此，在Aim 1中，我们将首先确定参与OX 40 L上调的相关TLR受体和信号通路。将在黑色素瘤动物模型中测试这一新发现的临床相关性（目的2）。最后，在目标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.