Role of SHIP in NK Cell Biology

描述（由申请人提供）：在第二次更新中，我们建议继续进行三个新的调查领域，这些领域是上一个供资期间取得进展的直接后果。在目标1和2中，我们将进一步定义SHIP在NK效应子功能中的作用，重点是细胞因子产生和NK对宿主的耐受性。在目标3中，我们将利用我们最近鉴定的第一个可以选择性靶向体内SHIP 1活性的小分子，以确定这种新型化合物是否可以增强NK细胞的癌症控制。具体目标是：目标1：确定SHIP-/- NK细胞产生缺陷性细胞因子的分子基础。在之前的资助期间，我们意外地观察到SHIP是主要NK活化受体如NK1.1、NCR 1/NKp 46和NKG 2D有效诱导3-IFN所必需的。在这个目标中，我们将确定如何广泛的SHIP-缺陷损害生产的3-IFN和其他细胞因子和趋化因子产生的NK细胞。此外，我们将定义这种缺陷的分子基础。目的2：通过NK细胞区室来确定SHIP在自身耐受中的作用。在之前的资助期间，我们发现鼠（Ly 49）和人（KIR）NK抑制受体对MHC I类配体的表达和代表性受到SHIP的限制，并且SHIP优先在这些受体的高亲和力MHC-I配体的背景下发挥这种作用。在人类KIR的情况下，我们提供了初步的证据，SHIP是需要保持NK耐受宿主。在这个目标中，我们将确定SHIP是否在NK对自身的耐受性中起作用，并且在对NK抑制性受体的亲和力不同的MHC-I配体的背景下起作用。目的3：测试SHIP抑制剂增强NK细胞根除癌症的潜力。在上一个资助期间，我们开发了第一个SHIP酶活性的小分子抑制剂，其中一种对SHIP 1具有选择性，并且在体内具有显著的活性。此外，我们证明了来自具有高亲和力MHC-I配体的MHC单倍型的SHIP-/- NK细胞表现出对缺乏该配体的同种异体肿瘤的超常杀伤。SHIP还已知通过NK细胞限制针对肿瘤细胞的ADCC。因此，在这个目标中，我们将确定化学抑制SHIP是否可以提高NK细胞在体内根除癌症的能力。这将在三个不同的背景下进行检查，每个背景下都有很大的潜力转化为临床治疗。

DESCRIPTION (provided by applicant): In this second renewal we propose to pursue three new areas of investigation that are a direct consequence of advances made during the previous funding period. In Aims 1 and 2 we will further define the role that SHIP plays in NK effector function with a focus on cytokine production and NK tolerance to host. In Aim 3 we will capitalize on our recent identification of the first small molecules that can selectively target SHIP1 activity in vivo to determine if this novel compound can enhance cancer control by NK cells. The specific aims are: Aim 1: Determine the molecular basis for defective cytokine production by SHIP-/- NK cells. During the previous funding period we made the unexpected observation that SHIP is required for effective induction of 3-IFN by major NK activating receptors like NK1.1, NCR1/NKp46 and NKG2D. In this aim we will determine how broadly SHIP- deficiency impairs production of 3-IFN and other cytokines and chemokines produced by NK cells. In addition, we will define the molecular basis of this defect. Aim 2: Define the role of SHIP in self tolerance by the NK cell compartment. During the previous funding period we found that the expression and representation of both murine (Ly49) and human (KIR) NK inhibitory receptors for MHC class I ligands is limited by SHIP and that SHIP preferentially plays this role in the context of high affinity MHC-I ligands for these receptors. In the case of human KIR, we provide preliminary evidence that SHIP is required to maintain NK tolerance to the host. In this aim we will determine if SHIP plays a role in NK tolerance to self and does so in the context of MHC-I ligands that vary in their affinity for NK inhibitory receptors. Aim 3: Test the potential of SHIP inhibitors to enhance NK cell eradication of cancer. During the previous funding period we developed the first small molecule inhibitors of SHIP enzyme activity, one of which is selective for SHIP1 and has significant activity in vivo. In addition, we demonstrated that SHIP-/- NK cells from an MHC haplotype with a high affinity MHC-I ligand demonstrate supernormal killing of allogeneic tumors that lack this ligand. SHIP is also known to limit ADCC against tumor cells by NK cells. Thus, in this aim we will determine if chemical inhibition of SHIP can improve the ability of NK cells to eradicate cancer in vivo. This will be examined in three different contexts each of which has significant potential for translation to clinical therapy.