Role and therapeutic modulation of the RANK-RANKL molecule system in the NK cell immune surveillance of malignant hematopoietic diseases

RANK-RANKL分子系统在恶性造血疾病NK细胞免疫监视中的作用和治疗调节

• 批准号: 205985315
• 负责人: Professor Dr. Helmut Rainer Salih
• 金额: --
• 依托单位: Klinische Kooperationseinheit Translationale Immunologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/205985315?language=en
• 关键词: Role; therapeutic; modulation; RANK; RANKL

NK cells play an important role in the immunosurveillane of tumors and, due to their ability to potently mediate antibody-dependent cellular cytotoxicity (ADCC), largely contribute to the clinical efficacy of therapeutic antibodies like Rituximab. Accordingly, multiple strategies presently aim to increase the potential of antibodies to induce ADCC of NK cells against tumor cells. Both the direct anti-tumor reactivity and ADCC of NK cells are influenced by the various ligands for receptors expressed by NK cells, and neutralization of inhibitory molecules thus serves well to increase constitutive and therapeutically-induced NK cell anti-tumor immunity. In the last funding period we demonstrated that the TNFR family member RANK (mainly known for its role in bone metabolism) is expressed by NK cells while its counterpart RANKL is expressed by malignant hematopoietic cells. We found that RANKL is capable to transduce signals into the ligand-expressing malignant cells (reverse signaling) which lead to release of cytokines that act as autocrine/paracrine growth and survival factors in the malignant diseases. In addition, the factors released upon RANKL signaling impaired the anti-tumor reactivity of NK cells and induced RANK expression on NK cells, The latter was further found to transduce signals into NK cells that impair their anti-tumor reactivity thereby facilitating immune escape of the RANKL-expressing malignant cells. Based on these findings we developed Fc-engineered RANK-Ig fusion proteins that are capable to neutralize the detrimental function of RANKL on anti-tumor immunity while at the same time potently stimulating NK cell ADCC by targeting of the malignant cells.In the second funding period we aim to elucidate the signaling pathways that mediate the induction of cytokine release and metabolic activity in malignant hematopoietic cells following RANKL signaling. Moreover, we aim to determine the molecular mechanisms by which RANK mediates the observed differential inhibition of NK cell cytotoxicity and cytokine production. Based on our findings regarding the differential susceptibility of human and murine NK cells for ADCC-induction observed in syngeneic mouse tumor models, the focus of the upcoming studies is to establish suitable humanized mouse models to further preclinically characterize our Fc-engineered RANK-Ig fusion proteins. Such models are envisaged to finally validate our strategy to dually reinforce NK reactivity against malignant hematopoietic cells by neutralizing the inhibitory effects of RANKL and simultaneously targeting the RANKL-expressing malignant cells for NK cells ADCC. After the preclinical validation, we envisage our constructs to be produced in an University-owned production unit according to GMP guidelines with the aim to enable rapid clinical testing in cancer patients.

NK细胞在肿瘤的免疫监视中起着重要作用，由于它们能够有效地介导抗体依赖性细胞毒性（ADCC），在很大程度上有助于利妥昔单抗等治疗性抗体的临床疗效。因此，目前有多种策略旨在增加抗体的潜力，以诱导NK细胞对肿瘤细胞的ADCC。NK细胞的直接抗肿瘤反应性和ADCC都受到NK细胞表达的受体的各种配体的影响，因此抑制分子的中和可以很好地增强NK细胞的组成性和治疗性抗肿瘤免疫。在上一个资助期，我们证明TNFR家族成员RANK（主要以其在骨代谢中的作用而闻名）由NK细胞表达，而其对应的RANKL由恶性造血细胞表达。我们发现RANKL能够将信号转导到表达配体的恶性细胞中（反向信号传导），从而导致细胞因子的释放，这些细胞因子在恶性疾病中充当自分泌/旁分泌生长和生存因子。此外，RANKL信号所释放的因子可使NK细胞的抗肿瘤反应性受损，并诱导NK细胞上RANK的表达，进而发现NK细胞通过转导信号削弱其抗肿瘤反应性，从而促进表达RANKL的恶性细胞的免疫逃逸。基于这些发现，我们开发了fc工程的RANK-Ig融合蛋白，该蛋白能够中和RANKL对抗肿瘤免疫的有害功能，同时通过靶向恶性细胞有效地刺激NK细胞ADCC。在第二个资助期，我们的目标是阐明RANKL信号传导介导恶性造血细胞中细胞因子释放和代谢活性诱导的信号通路。此外，我们旨在确定RANK介导NK细胞毒性和细胞因子产生差异抑制的分子机制。基于我们在同基因小鼠肿瘤模型中观察到的人和小鼠NK细胞对adcc诱导的不同易感性的发现，未来研究的重点是建立合适的人源化小鼠模型，以进一步表征我们的fc工程RANK-Ig融合蛋白的临床前特征。设想这些模型最终验证我们的策略，通过中和RANKL的抑制作用，同时靶向表达RANKL的恶性细胞对NK细胞ADCC双重增强NK对恶性造血细胞的反应性。在临床前验证之后，我们设想我们的结构将根据GMP指南在大学拥有的生产单位生产，目的是在癌症患者中进行快速临床试验。