Using human skin grafted mice to identify biomarkers of exposure and study effects of radiation on skin

摘要/摘要 在发生大规模辐射或核事件时，当务之急是区别对待暴露在 来自忧心忡忡的个体，并识别处于辐射诱导组织损伤风险的个体。人类 它们对辐射诱导的组织损伤的敏感性不同，控制辐射敏感性的因素并不完全 了解，而且没有生物标记物来识别处于辐射诱导组织损伤风险中的个人。这个 皮肤是一种免疫活性屏障组织，会受到所有类型的外部辐射事件的影响。 皮肤在视觉上是可观察的，非侵入性测试可以接触到，并且很容易取样，因此它适合于 各种测试方式。我们建议对免疫完好的活体人体皮肤移植物进行照射和研究。 在免疫缺陷的NSG小鼠身上识别检测辐射暴露和预测辐射的生物标记物 导致组织损伤。在目标1中，我们将研究辐射对成人皮肤移植物的影响。 NSG小鼠。我们将研究DNA损伤修复蛋白，活性氧物种，上皮屏障功能和 成人皮肤移植物受0、0.5、1.0、2.0和5.0Gy射线照射后基因表达的变化。我们会 确定暴露后24小时内检测到辐射暴露的生物标志物(第一阶段)，保持可检测到 长期和/或与后来的组织损伤相关(第二阶段)，我们将在 30名人体供皮者的单独验证队列(第三阶段)。在目标2中，我们将研究辐射的影响 在人类新生儿包皮移植物上，含有抗原提呈细胞但缺乏T细胞的组织，作为模型 对儿科和免疫受损人群都是如此。我们将测试AIM 1中确定的生物标记物 能够在24小时内检测到辐射暴露，并预测新生儿包皮的组织损伤。如果 必要时，我们将确定新的生物标记物，用于儿科和免疫低下人群。在《目标3》中， 我们将开发快速护理点测试，以检测我们在AIMS 1和2中识别的生物标志物。皮肤是一种 可获得的组织，可作为预测其他组织辐射损伤风险的替代研究 网站。通过研究不同人类捐赠者群体中免疫完好的皮肤，我们将确定 对i)人类有用的生物标志物，ii)对辐射具有不同敏感性的多样化的异种繁殖种群， 和iii)儿科和免疫受损人群。预测后续疾病的生物标志物的鉴定 皮肤中的组织损伤将识别对辐射敏感的个体。我们的护理点测试有可能 快速筛查潜在接触人群并确定有组织损伤风险的个人和 将需要进一步的医疗护理。

Summary/Abstract In the event of a large scale radiologic or nuclear event, the immediate needs are to discriminate exposed individuals from the worried well and identify individuals at risk for radiation-induced tissue damage. Humans vary in their sensitivity to radiation-induced tissue injury, the factors that control radiation sensitivity are not fully understood, and there are no biomarkers to identify individuals at risk for radiation-induced tissue damage. The skin is an immunologically active barrier tissue that will be impacted by all types of external radiation events. Skin is visually observable, accessible to non-invasive testing and easily sampled, making it amenable to a variety of testing modalities. We propose to irradiate and study living, immunologically intact human skin grafts on immunodeficient NSG mice to identify biomarkers that detect exposure to radiation and predict radiation induced tissue damage. In Aim 1, we will study the effects of irradiation on adult human skin grafts carried by NSG mice. We will study DNA damage repair proteins, reactive oxygen species, epithelial barrier function and gene expression changes in adult human skin grafts exposed to 0, 0.5, 1.0, 2.0 or 5.0 Gy irradiation. We will identify biomarkers that detect radiation exposure within 24 hours of exposure (Phase I), remain detectable longer term and/or correlate with later tissue injury (Phase II) and we will validate these biomarkers in a separate validation cohort of 30 human skin donors (Phase III). In Aim 2, we will study the effects of irradiation on human neonatal foreskin grafts, a tissue that contains antigen presenting cells but lacks T cells, as a model for both pediatric and immunocompromised populations. We will test biomarkers identified in Aim 1 for their ability to detect radiation exposure within 24 hours and to predict tissue injury in neonatal foreskin. If necessary, we will identify new biomarkers for use in pediatric and immunocompromised populations. In Aim 3, we will develop rapid point-of-care tests to detect the biomarkers we identify in Aims 1 and 2. The skin is an accessible tissue that can be studied as a proxy to predict the risk of radiation-induced injury at other tissue sites. By studying immunologically intact skin from a diverse population of human donors, we will identify biomarkers that are useful in i) humans, ii) a diverse, outbred population with differing sensitivities to radiation, and iii) pediatric and immunocompromised populations. Identification of biomarkers that predict subsequent tissue damage in skin will identify radiation sensitive individuals. Our point-of-care tests have the potential to rapidly screen potentially exposed populations and identify individuals who are at risk for tissue damage and will require further medical attention.