Investigating the therapeutic potential of anti-GITR antibodies

研究抗 GITR 抗体的治疗潜力

• 批准号: 2136410
• 金额: --
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2136410
• 关键词: Investigating; therapeutic; potential; anti; GITR

Re-activating anti-tumour immune responses, and avoiding unwanted autoimmunity, is a primary goal of anti-cancer immunotherapies. Antibodies that block checkpoint inhibitors, to prevent immune inhibition, have been clinically successful. Glucocorticoid-Induced TNFR-Related (GITR) is a cell surface co-stimulatory receptor that belongs to the same tumour necrosis factor (TNFR) superfamily as OX40 and 4-1BB. Constitutive expression of GITR is high on T regulatory cells (T-regs), but low on both naïve and memory effector T cells (T-effs). T-regs are an immune-suppressive cell type that, in multiple cancers, have been implicated in preventing the activation of anti-tumour responses (3). Because of high GITR expression on T-regs, depletion of these cells with therapeutic antibodies has been proposed as an anti-tumour therapy. Activated T-effs dramatically increase GITR surface expression. The stimulation of the GITR pathway increased T-eff proliferation and the expression of pro-inflammatory cytokines like IL-2 and IFNy. Furthermore, tumours with higher levels of GITRL expression had increased numbers of infiltrating CD4+ and CD8+ T cells and delayed growth. Considering the role GITR plays in modulating immune responses, antibodies directed against this surface protein are currently being investigated as anti-tumour immuno-therapeutics.The University of Southampton antibody and vaccine group (AVG) have developed a panel of anti-human GITR (anti-huGITR) antibodies. In this project, we will characterise the function of anti-huGITR antibodies in vitro and in vivo. Research question, aims and objectives Understand how anti-huGITR antibodies influence immune responses using a human GITR knock-in transgenic mouse model (huGITRKI) that expresses human GITR surface protein.Aim 1. Characterise human GITR protein expression and investigate how different anti-huGITR antibodies alter immune responses in vitro. Determine the kinetics of binding affinity as well as the binding epitopes of the anti-GITR antibodies. I. To determine the kinetics of GITR expression, human PBMCs and splenocytes from huGITRKI transgenic mice will be activated in vitro with various stimuli. Changes in surface protein are then measured using flow cytometry. II. Measure cellular proliferation of CD4+ and CD8+ T cells post activation and treatment with each anti-GITR antibody. III. Determine how GITR antibodies influence cell signalling. IV. Determine the kinetics and binding affinity of anti-GITR antibodies using surface plasma resonance.V. Determine the optimal binding epitope of each anti-GITR antibody.

重新激活抗肿瘤免疫反应，避免不必要的自身免疫，是抗癌免疫疗法的主要目标。阻断检查点抑制剂以防止免疫抑制的抗体已在临床上取得成功。糖皮质激素诱导的肿瘤坏死因子受体相关（GITR）是一种细胞表面共刺激受体，与OX 40和4-1BB属于相同的肿瘤坏死因子（TNFR）超家族。GITR的组成型表达在调节性T细胞（T-effs）上高，但在幼稚和记忆效应T细胞（T-effs）上低。T细胞是一种免疫抑制细胞类型，在多种癌症中，它参与阻止抗肿瘤反应的激活（3）。由于T-T细胞上的高GITR表达，已经提出用治疗性抗体耗尽这些细胞作为抗肿瘤疗法。活化的T-effs显著增加GITR表面表达。GITR途径的刺激增加了T-eff增殖和促炎细胞因子如IL-2和IFN γ的表达。此外，具有较高水平GITRL表达的肿瘤具有增加的浸润性CD 4+和CD 8 + T细胞数量和延迟的生长。考虑到GITR在调节免疫应答中所起的作用，针对这种表面蛋白的抗体目前正在被研究作为抗肿瘤免疫疗法。南安普顿大学抗体和疫苗组（AVG）已经开发了一组抗人GITR（抗huGITR）抗体。在本项目中，我们将在体外和体内验证抗huGITR抗体的功能。研究问题、目的和目标使用表达人GITR表面蛋白的人GITR敲入转基因小鼠模型（huGITRKI）了解抗huGITR抗体如何影响免疫应答。表征人GITR蛋白表达并研究不同抗huGITR抗体如何改变体外免疫应答。确定结合亲和力的动力学以及抗GITR抗体的结合表位。I.为了确定GITR表达的动力学，将在体外用各种刺激物活化来自huGITRKI转基因小鼠的人PBMC和脾细胞。然后使用流式细胞术测量表面蛋白的变化。二.在活化和用每种抗GITR抗体处理后测量CD 4+和CD 8 + T细胞的细胞增殖。三.确定GITR抗体如何影响细胞信号传导。四.使用表面等离子体共振确定抗GITR抗体的动力学和结合亲和力。V.确定每种抗GITR抗体的最佳结合表位。