Non-Invasive Quantification of Vaccine-Mediated Antigen Delivery to

疫苗介导的抗原递送的无创定量

• 批准号: 7984054
• 负责人: HYAM Isaac LEVITSKY
• 金额: $ 21.5万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-25 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7984054
• 关键词: APC Vaccine; Adjuvant; Antigen-Presenting Cells; Antigens; B-Lymphocytes; Cancer Model; Cancer Vaccines; Cells; Computer software; Contrast Media; Evaluation; Generations; Immune response; Immunity; In Situ; Label; Magnetic Resonance Imaging; Malignant neoplasm of lung; Measures; Mediating; Methods; Modeling; Molecular; Monitor; Monoclonal Antibodies; Mus; Nanotechnology; Peptides; Phenotype; Process; Property; Resolution; Signal Transduction; Site; Staging; System; T-Lymphocyte; Techniques; Technology; Therapeutic; Tumor Antigens; Vaccination; Vaccine Adjuvant; Vaccine Antigen; Vaccines; arm; base; cellular imaging; clinical application; in vivo; iron oxide; lymph nodes; mouse model; pre-clinical; therapeutic protein; trafficking; tumor; vaccine-induced immunity

A major parameter limiting immune responses to vaccination is the number of activated antigen presenting cells (APCs) that capture antigen from the vaccine site and migrate to draining lymph nodes (LNs), the site where T and B cell priming occurs. Currently, a quantitative non-invasive technique for monitoring in vivo antigen capture and dehvery is laclting. The use of cellular magnetic resonance imaging (MRI) is a promising approach for this purpose; however, cellular imaging currently requires ex vivo pre-labeling of cells with contrast agents followed by reintroduction of cells into the subject being monitored. Using mouse models, we have developed an in vivo labehng method which relies upon the capture of vaccine antigen-associated superparamagnetic iron oxide (SPIO) by endogenous antigen presenting cells, in situ, in order to quantify AFC delivery to LNs. In this system, MRI is capable of monitoring the trafficking of magnetically labeled APCs in vivo that are responsible for inducing tumor-specific immune responses. Analysis of lymph node MR images using dedicated software enables signal quantification through the generation of pixel intensity histograms. Excellent correlation is observed between in vivo and ex vivo quantification of vaccine antigen-loaded APCs, with resolution sufficient to detect increased APC trafficking elicited by an adjuvant. Furthermore, APCs that capture SPIO (and antigen) and traffic to LN can subsequently be magnetically recovered ex vivo, allowing for detailed cellular and molecular studies of the upstream parameters that influence the afferent arm of vaccine-induced immunity. Using murine vaccine models targeting lung cancer, we now propose to examine the correlation between the extent of APC trafficking as measured by MRI and the quantity and quality of the downstream immune response. This information will be used to evaluate candidate vaccine adjuvants for their ability to augment this critical step In generating systemic immunity. We will also extend this technology to additional vaccine platforms setting the stage for clinical application.

限制免疫应答的一个主要参数是活化的抗原提呈细胞（APCs）的数量，这些细胞从疫苗部位捕获抗原并迁移到引流淋巴结（LNs），即T和B细胞启动的部位。目前，一种用于监测体内抗原捕获和递送的定量非侵入性技术是哺乳。使用细胞磁共振成像（MRI）是一种很有前途的方法；然而，细胞成像目前需要用造影剂对细胞进行离体预标记，然后将细胞重新引入被监测的受试者体内。利用小鼠模型，我们开发了一种体内标记方法，该方法依赖于内源性抗原呈递细胞原位捕获疫苗抗原相关的超顺磁性氧化铁（SPIO），以量化AFC向LNs的递送。在该系统中，MRI能够监测体内磁标记apc的运输，这些apc负责诱导肿瘤特异性免疫反应。使用专用软件分析淋巴结MR图像，通过生成像素强度直方图实现信号量化。在疫苗抗原负载APC的体内和体外定量之间观察到极好的相关性，其分辨率足以检测由佐剂引起的APC贩运增加。此外，捕获SPIO（和抗原）并传输到LN的apc随后可以在体外磁回收，从而允许对影响疫苗诱导免疫传入臂的上游参数进行详细的细胞和分子研究。