Positive and Negative Regulation of Natural Killer Cells After BMT

描述（由申请人提供）：造血干细胞移植（HSCT）越来越多地用于癌症治疗，并已显示对几种癌症提供显著的移植物抗肿瘤效应。然而，重要的问题限制了HSCT的疗效，包括肿瘤复发、移植物排斥、移植物抗宿主病（GVHD）和严重的免疫缺陷期，使患者极易受到机会性感染。自然杀伤（NK）细胞代表先天免疫反应的关键组成部分，并越来越多地用作HSCT的治疗手段。然而，NK细胞及其调节的日益复杂性沿着对HSCT后NK细胞发育/恢复的相对缺乏的知识，严重阻碍了NK细胞作为免疫途径的临床应用。NK亚群的存在，并可能显着不同的功能，由于差异许可。我们将建立在令人兴奋的初步数据表明，小鼠NK细胞亚群对HSCT的结果有显着的相反和差异的影响，使用几个临床前模型评估病毒耐药性，肿瘤复发和供体移植/GVHD后同源或同种异体HSCT的影响。为此，我们提出了3个具体目标：具体目标1将建立在我们的数据基础上，这些数据表明Ly 49 G2代表了NK细胞的全球活化/发育标志物，因为它在HSCT后或一般活化时占主导地位，并且不依赖于MHC。这一目标将研究的机制，这和其他子集的扩展，并确定其功能作用，使用耐小鼠巨细胞病毒（MCMV）同源HSCT。由于初步数据表明，在HSCT后确实可以观察到Ly 49 A+、Ly 49 G2+和Ly 49 C/I+亚群的NK细胞许可，而在静息小鼠中则没有观察到病毒耐药性，因此我们假设HSCT后的环境代表了理解NK细胞亚群相互作用的独特手段，并且Ly 49家族在功能/许可方面是多样的。具体目标2将建立在我们令人兴奋的初步数据，表明宿主NK细胞亚群似乎能够相互调节，与许可和执行“辅助”或“抑制”功能有关的供体造血移植后异基因HSCT一致。这将表征这些亚组，其表现为许可或未许可，并寻求扩大其在同种异体HSCT中的体内有益作用。这一目标还将确定对HSCT后结局的长期影响，包括骨髓和淋巴重建和GVHD。具体目标3将建立在来自先前目标的数据和新数据的基础上，以确定供体转移的NK细胞“辅助”或“抑制/效应”亚群在同种或同种异体HSCT后的抗肿瘤作用方面的作用机制。该目的将寻求通过施用免疫调节剂（IL-15和TGF-2的中和）来增强这些作用。最后，我们将确定使用亚组的过继NK细胞治疗对癌症干细胞（CSC）群体的影响，这些群体可能代表NK细胞治疗（使用亚组）的关键靶点。这些目标不仅有助于表征小鼠NK细胞亚群的功能，而且还有助于开发临床上利用人NK细胞或其亚群进行治疗的方法，特别是在HSCT和癌症的背景下，因为人亚群变得更好地定义。

DESCRIPTION (provided by applicant): Hematopoietic stem cell transplantation (HSCT) is increasingly used in cancer therapy and has been shown to provide significant graft-versus-tumor effects for several cancers. However, significant issues limit the efficacy of HSCT including relapse for the tumor, graft rejection, graft-versus-host disease (GVHD) and a profound period of immune deficiency leaving the patient highly susceptible to opportunistic infections. Natural killer (NK) cells represent critical components of the innate immune response and are being increasingly used as a therapeutic arm in HSCT. However, the increasing complexity of NK cells and their regulation along with the relatively sparse knowledge on NK cell development/recovery after HSCT seriously hampers clinical application of NK cells as an immunotherapeutic approach. NK subsets exist and may differ markedly in their function due to differential licensing. We will build on exciting preliminary data demonstrating that mouse NK cell subsets have markedly opposing and differential effects on HSCT outcome using several preclinical models assessing effects on viral resistance, tumor relapse and donor engraftment/GVHD after congenic or allogeneic HSCT. To do this we propose 3 SPECIFIC AIMS: Specific Aim 1 will build on our data demonstrating that Ly49G2 represents a global activation/development marker of NK cells as it is predominant after HSCT or with general activation and is independent of MHC. This aim will examine the mechanisms underlying the expansion of this and other subsets and determine their functional roles using resistance to mouse cytomegalovirus (MCMV) following congenic HSCT. As preliminary data indicate that NK cell licensing with Ly49A+, Ly49G2+, and Ly49C/I+ subsets can indeed be observed post-HSCT and not in resting mice with regard to viral resistance, we hypothesize that the environment post-HSCT represents a unique means to understand NK cell subset interactions and that the Ly49 family is diverse with regard to function/licensing. Specific Aim 2 will build on our exciting preliminary data demonstrating that host NK cell subsets appear capable of regulating each other consistent with licensing and performing "helper" or "suppressor" functions with regard to donor hematopoietic engraftment after allogeneic HSCT. This will characterize these subsets which appear to behave as licensed or unlicensed and seek to expand on their beneficial effects in vivo in allogeneic HSCT. This aim will also determine long-term effects on outcome after HSCT including myeloid and lymphoid reconstitution and GVHD. Specific Aim 3 will build on the data from the previous aims and new data to determine the mechanisms underlying the effects of donor transferred NK cell "helper" or "suppressor/effector" subsets with regard to anti-tumor effects after congenic or allogeneic HSCT. This aim will seek to augment these effects with administration of immunomodulating agents (IL-15 and neutralization of TGF-2). Finally, we will determine the effects of the adoptive NK cell therapy using subsets against cancer stem cell (CSC) populations which may represent critical targets for NK cell therapy (using subsets). These aims will not only aid in the characterization of mouse NK cell subsets with regard to function but will also help in developing means to clinically exploit human NK cells or their subsets therapeutically, particularly in the context of HSCT and cancer as human subsets become better defined.