Role of SHIP in NK Cell Biology

描述（由申请人提供）：在第二次续期中，我们建议进行三个新的研究领域，这些研究领域是前一个资助期间取得进展的直接结果。在Aims 1和2中，我们将进一步定义SHIP在NK效应功能中的作用，重点关注细胞因子的产生和NK对宿主的耐受性。在Aim 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SHIP1活性的小分子来确定这种新化合物是否可以增强NK细胞对癌症的控制。目的1：确定SHIP-/- NK细胞产生缺陷细胞因子的分子基础。在之前的资助期内，我们意外地观察到SHIP是NK1.1、NCR1/NKp46和NKG2D等主要NK激活受体有效诱导3-IFN所必需的。在这个目标中，我们将确定SHIP-缺陷在多大程度上损害NK细胞产生的3-IFN和其他细胞因子和趋化因子的产生。此外，我们将定义这种缺陷的分子基础。目的2：明确SHIP在NK细胞区自我耐受中的作用。在之前的资助期间，我们发现小鼠（Ly49）和人类（KIR） NK抑制受体对MHC I类配体的表达和表征都受到SHIP的限制，并且SHIP在这些受体的高亲和力MHC-I配体的背景下优先发挥这一作用。在人类KIR的情况下，我们提供的初步证据表明，需要SHIP来维持NK对宿主的耐受性。在这个目的中，我们将确定SHIP是否在NK对自身的耐受性中起作用，并且在MHC-I配体对NK抑制受体的亲和力不同的情况下起作用。目的3：测试SHIP抑制剂增强NK细胞根除癌症的潜力。在之前的资助期间，我们开发了首个SHIP酶活性的小分子抑制剂，其中一种对SHIP1具有选择性，并且在体内具有显着的活性。此外，我们证明了具有高亲和力MHC- i配体的MHC单倍型的SHIP-/- NK细胞对缺乏这种配体的异体肿瘤表现出超常的杀伤作用。SHIP也被认为可以限制NK细胞对肿瘤细胞的ADCC。因此，在这个目的中，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。这将在三种不同的情况下进行检查，每一种情况都有转化为临床治疗的重大潜力。

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.