Matrix metalloproteinase-2 modulates inflammation via TLR2

描述(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，尽管肿瘤内积累了抗原特异性T细胞，但对大多数患者的持久疗效有限。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，对这些失败负有部分责任。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，它通过影响肿瘤间质、血管和激活因子如转化生长因子和肿瘤坏死因子来促进肿瘤的生长和侵袭。基质金属蛋白酶-2(MMP2)是一种明胶酶，在包括黑色素瘤在内的大多数肿瘤中都有过度表达，其表达与肿瘤的侵袭转移和不良的生存及预后有关。我们最近发现，酶激活的基质金属蛋白酶-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，只有酶活性的基质金属蛋白酶-2抑制IL-12的产生，而活性和非活性的基质金属蛋白酶-2构象都能诱导OX40L的上调。值得注意的是，我们还在几个患者中检测到了TIL，这些患者表现出对基质金属蛋白酶-2的特异性反应。这些反应是TH2样的，它们的存在被发现与存活率呈负相关。因此，基质金属蛋白酶-2同时起到内源性TH2“调节剂”和肿瘤相关抗原的作用，这可能在一定程度上解释了黑色素瘤中出现不利的TH2反应。我们以前描述了IL-12抑制的机制，这涉及到IIFN受体的酶裂解，从而减少STAT-1的磷酸化和IL-12p35的转录。自那以后，我们发现了树突状细胞和TME调节MMP2失调的其他新的免疫机制：MMP2直接在DCs和黑色素瘤细胞系上触发TLR-2介导的信号转导，分别诱导OX40L的表达和促炎细胞因子的产生。因此，在Aim1中，我们将首先确定参与OX40L上调的相关TLR受体和信号通路。这一新发现的临床相关性将在黑色素瘤动物模型中进行测试(目标2)。最后，在目标3中，我们将评估基质金属蛋白酶-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.