Oxidized lipids and UV immunosuppression

描述（由申请人提供）： 项目概要：我们研究的主要目的是从机制上描述紫外线B辐射（UVB）诱导的全身免疫抑制。UVB的免疫抑制作用与这种环境刺激诱发皮肤癌的能力有关。此外，UVB辐射治疗在临床上用于治疗炎症性皮肤病，在很大程度上是由于其免疫抑制作用。 计划中的研究计划利用我们实验室和其他实验室先前研究的结果，表明UVB介导的全身免疫抑制涉及表皮细胞响应UVB产生的新型甘油磷酸胆碱衍生脂质。这些化合物，其中一些尚未进行结构表征，作为血小板活化因子（PAF）受体的激动剂。越来越多的证据表明，这些PAF-R激动剂通过细胞类型和细胞因子（包括肥大细胞、环氧合酶-2产生的类花生酸、白细胞介素-10和组胺）的复杂相互作用发挥免疫抑制作用。 两个具体的目标是计划使用一个完善的接触性超敏反应的小鼠模型，从机械上表征UVB介导的全身免疫抑制的复杂途径。第一个目标将使用质谱法对UVB在小鼠皮肤中产生的PAF-R激动剂进行结构表征和定量。将使用PAF酶促合成缺陷的小鼠和全身性抗氧化剂的使用来评估酶促以及通过甘油磷酸胆碱的非酶促自由基介导的氧化产生的这些新型PAF-R配体的量。第二个目标将使用新的小鼠移植研究肥大细胞和调节性T细胞的作用的特点。完成计划中的研究，以表征参与UVB介导的全身性免疫抑制的细胞类型和介质，应导致这一重要的过程密切参与皮肤癌的理解增强。 公共卫生相关性： 项目叙述：我们研究的主要目标是从机制上描述参与紫外线B辐射（UVB）介导的全身免疫抑制的细胞类型和介质。UVB的免疫抑制作用与这种环境刺激诱发皮肤癌的能力有关。这些皮肤癌和癌前光化性角化病引起的慢性阳光照射是最常见的形式的肿瘤性疾病发现的退伍军人。虽然通常与死亡率增加无关，但光化性肿瘤构成了卫生保健资源的巨大负担并增加了发病率。此外，UVB辐射治疗在临床上用于治疗炎症性皮肤病，在很大程度上是由于其免疫抑制作用。这些研究应能增进对这一重要进程的了解。

DESCRIPTION (provided by applicant): PROJECT SUMMARY: The primary goal of our research is to mechanistically characterize systemic immunosuppression induced by ultraviolet B radiation (UVB). The immunosuppressive effects of UVB are involved in the ability of this environmental stimulus to induce skin cancers. Moreover, UVB radiation treatments are used clinically to treat inflammatory skin disorders, in great part to its immunosuppressive effects. The planned research plans to take advantage of results of previous studies both in our laboratory and others indicating that UVB-mediated systemic immunosuppression involves novel glycerophosphocholine-derived lipids produced by epidermal cells in response to UVB. These compounds, some of which have not been structurally characterized, act as agonists for the Platelet-activating Factor (PAF) receptor. Accumulating evidence suggests that these PAF-R agonists exert immunosuppressive effects via a complex interplay of cell types and cytokines including mast cells, cyclooxygenase-2-produced eicosanoids, interleukin-10 and histamine. Two specific aims are planned to mechanistically characterize the complex pathway of UVB-mediated systemic immunosuppression using a well-established murine model of contact hypersensitivity. The first aim will use mass spectrometry to structurally characterize and quantitate PAF-R agonists produced by UVB in murine skin. The amounts of these novel PAF-R ligands produced enzymatically as well as through non- enzymatic free radical-mediated oxidation of glycerophosphosphocholines will be assessed using a mouse defective in PAF enzymatic synthesis and use of systemic antioxidants. The second aim will characterize the roles of mast cells and regulatory T cells using novel murine transplantation studies. Completion of the planned studies to characterize the cell types and mediators involved in UVB-mediated systemic immunosuppression should result in an enhanced understanding of this important process intimately involved in skin cancer. PUBLIC HEALTH RELEVANCE: PROJECT NARRATIVE: The primary goal of our research is to mechanistically characterize the cell types and mediators involved in ultraviolet B radiation (UVB)-mediated systemic immunosuppression. The immunosuppressive effects of UVB are involved in the ability of this environmental stimulus to induce skin cancers. These skin cancers and pre- cancerous actinic keratoses induced by chronic sun exposure are the most common form of neoplastic disorders found in veterans. Though usually not associated with increased mortality, actinic neoplasias constitute an enormous burden of health care resources and increased morbidity. Moreover, UVB radiation treatments are used clinically to treat inflammatory skin disorders, in great part to its immunosuppressive effects. These studies should result in an enhanced understanding of this important process.