Combination immunotherapy for neuroblastoma: model of innate tumor immunity

描述(申请人提供)：神经母细胞瘤(NB)是儿童最常见的颅外实体瘤。虽然密集的诱导化疗和积极的手术提高了年轻患者的缓解率，但在老年患者和40%的化疗耐药的NB患者中，结果并不令人印象深刻。确诊时18个月大的儿童转移性神经母细胞瘤的长期无复发存活率仅为20%。这些令人失望的结果是寻求新的治疗方法的令人信服的理由。一种成功的替代方法是用3F8进行免疫治疗，3F8是一种小鼠抗GD2糖脂抗原的单抗，普遍存在于NB细胞中。虽然3F8给药对缓解期的NB患者有明显的生存益处，但对于软组织耐药的NB患者或进展性疾病患者则无效。这可能部分是因为它依赖于抗体依赖的细胞介导的细胞毒作用(ADCC)，后者主要由自然杀伤(NK)细胞介导，而严重预治疗的患者会耗尽自然杀伤细胞(NK细胞)。从健康的同种异体来源过继转移NK细胞可能会恢复和增强这些低风险患者的3F8效应。自然杀伤(NK)细胞是通过多种途径具有抗肿瘤活性的淋巴细胞，包括通过与CD16Fc受体结合的ADCC。然而，NK细胞对细胞毒反应的能力是由其细胞表面受体决定的，特别是针对Sel-MHC I类分子的抑制性和激活性KIR。为了最大限度地发挥过继转移的NK细胞的作用，应该选择最有可能产生NK同种异体反应和获得最高功能NK反应的供者。这可以通过根据供者和患者的人类白细胞抗原和KIR基因型来选择供者，并通过使用可以反映体内肿瘤MHC环境的体外系统来评估NK功能来实现。在该提案的第一个目的中，我们建议上调肿瘤上的MHC-I类分子选择性地抑制正常反应的NK细胞群，使正常功能低下的、无证的NK细胞群介导患者的ADCC。在抗体治疗过程中阐述的炎性细胞因子也可能增强未经许可的NK活性。未经许可的NK人群的活跃性可能很大，在选择NK捐赠者进行收养转移时应该考虑到这一点。这项建议为高危神经母细胞瘤的治疗提供了一种新的免疫治疗方法。3F8单抗与来自适当选择的供者的过继转移的NK细胞相结合，将增加ADCC、抗体效力和肿瘤根除。由于这些免疫学方法从未在实体瘤或儿科人群中进行联合研究，因此有必要进行一项第一阶段研究，以检查3F8联合不断增加的NK细胞剂量的安全性，这是该提案的第二个目标。介绍了NK和3F8治疗的潜在毒性、毒性监测计划、剂量递增计划、预期结果和停药规则。供体-受体KIR/HLA免疫遗传学和供体FCR基因多态性与NK激活和体外杀伤NB靶细胞功能相关。安全和可行性的论证 将过继转移的NK细胞与单抗相结合，不仅将为预后不良的NB患者带来更有效的治疗方法，而且将广泛适用于目前使用单抗治疗的其他癌症群体，如淋巴瘤和乳腺癌。将供者-受者KIR/HLA效应与结果相关联将阐明供者优先排序算法，并为未来的NK免疫治疗研究提供预后价值。 与公共健康相关：自然杀伤(NK)细胞是人体免疫系统的重要组成部分，保护个人免受癌症侵袭。这项建议旨在帮助医生使用NK细胞和免疫系统来治疗患有神经母细胞瘤的儿童，神经母细胞瘤是一种儿童癌症。这项研究的发现将为其他可能被NK细胞杀死的癌症提供信息。

DESCRIPTION (provided by applicant): Neuroblastoma (NB) is the most common extracranial solid tumor of childhood. While intensive induction chemotherapy and aggressive surgery have improved remission rates in young patients, results have been less impressive in older patients and in the 40% of patients with chemo resistant NB. Metastatic NB in children > 18 months of age at diagnosis carries a long-term relapse-free survival of only ~20%. These disappointing results are compelling reasons for pursuing novel therapeutic approaches. One successful alternative approach has been immunotherapy with 3F8, a murine IgG3 monoclonal antibody to the GD2 glycolipid antigen ubiquitously present on NB cells. While 3F8 administration confers a clear survival benefit to NB patients in remission, it is not effective for patients with resistantsoft tissue NB or patients with progressive disease. This may be due in part to its dependence on antibody- dependent cell-mediated cytotoxicity (ADCC), the latter mediated largely by natural killer (NK) cells, which are depleted in heavily pre-treated patients. Adoptive transfer of NK cell from a healthy allogeneic source may restore and enhance 3F8 effects in these poor-risk patients. Natural killer (NK) cells are lymphocytes that have the capacity for antitumor activity via multiple pathways, including ADCC through engagement of the CD16 Fc receptor. The capacity of an NK cell for cytotoxic response, however, is dictated by its cell surface receptors, specifically the inhibitory and activating killer-Ig like receptors (KIR) that are specific for sel-MHC class I molecules. To maximize the effects of adoptively transferred NK cells, one should select donors from whom there is the greatest likelihood of engendering NK alloreactivity and of achieving highest functional NK response. This can be accomplished by selecting donors based on the HLA and KIR genotypes of the donor and the patient and by evaluating NK function using an in vitro system that may reflect the tumor MHC environment in vivo. In the first aim of the proposal, we propose that up regulation of MHC class I molecules on the tumor selectively inhibits normally responsive NK populations, leaving the normally hypofunctional, "unlicensed" NK population to mediate ADCC in patients. Inflammatory cytokines elaborated during antibody therapy may also enhance unlicensed NK activity. The activity of the unlicensed NK population can be significant and should be considered when selecting an NK donor for adoptive transfer. This proposal presents a novel immunotherapeutic approach for the treatment of high-risk neuroblastoma. Combination of 3F8 monoclonal antibody with adoptively transferred NK cells from appropriately selected donors should increase ADCC, antibody efficacy, and tumor eradication. Because these immunologic approaches have never been studied in combination for a solid tumor or in the pediatric population, a phase I study to examine the safety of 3F8 combined with escalating doses of NK cells is necessary and represents the second aim of the proposal. Potential toxicities of NK and 3F8 therapies, a toxicity monitoring plan, dose escalation plan, the expected outcome and stopping rules are presented. Donor-recipient KIR/HLA immunogenetics and donor FcR polymorphism will be correlated with NK activation and cytotoxic function against NB target cells in vitro. Demonstration of safety and feasibility of combining adoptively transferred NK cells with monoclonal antibody will not only result in a more potent therapeutic approach for poor-prognosis NB patients, but will be broadly applicable to other cancer populations such as lymphoma and breast carcinoma currently treated with monoclonal antibodies. Correlating donor-recipient KIR/HLA effects with outcome will clarify donor prioritization algorithms and provide prognostic value for future NK immunotherapy studies. PUBLIC HEALTH RELEVANCE: Natural killer (NK) cells are a vital component of the body's immune system, protecting the individual from developing cancer. This proposal is designed to help physicians use NK cells and the immune system as treatment for children with neuroblastoma, a childhood cancer. Findings from this study will be informative for other cancers that may also be killed by NK cells.