Immunotoxic effects of lead on cytokine expression

描述（由申请人提供）：铅 (Pb) 改变的机制 免疫反应是多因素的，MHC 和非 MHC 基因都可能 涉及，因为似乎对 T 细胞、B 细胞有独立的影响 和巨噬细胞，这些效应似乎涉及不同的细胞因子和 信号/转录因子。该项目的长期目标是 确定 Pb 改变淋巴细胞发育的亚细胞机制 （对记忆细胞来说是幼稚的）以及记忆 T 细胞的激活和反应性 这可能会影响免疫力，导致反应低下或过度。这个 该提案检验了重金属铅可以改变免疫状态的假设 通过生化和分子调节导致优先 开发 2 型反应的环境，并依赖于 防御传染病所需的特定类型的免疫反应 剂、癌症或自我反应反应的调节，这种“倾斜”可能 增加与 lype-2 免疫减弱和 lype-2 免疫增强相关的病理 回应。化学、物理和/或情绪压力之间的协同作用可以 增强免疫反应向]型或2型反应的倾斜； 适当的防御需要短期的不平衡，但长期的不平衡是必要的 不平衡会加剧病理。因此，环境因素如 Pb 可能 改变平衡足以增加发病率。突变体（基因过度表达 或缺陷）H-2d小鼠将被用来评估特定的参与 基因中的“倾斜”现象。需要解决的具体问题是：如何 Pb 改变 IFNγ 的动力学产生；巨噬细胞如何反应，例如 ILl 0、ILl 2 或 ILl 8 的产生发生改变，并且细胞硫醇是否 涉及修改； T细胞能否实现Pb“倾斜” 仅特定于 OVA 或 T 细胞是否具有自身反应性（或金属相关性） 无论是 B 细胞还是特定类型的 T 细胞，都需要 需要特定的细胞因子亚群（例如 NK 样 T 细胞） 环境； IL-4 反应性涉及哪些分子机制 T 细胞；以及哪些细胞负责诱导 2 型环境 由铅。将通过流式细胞术和免疫荧光分析细胞类型 显微镜。细胞因子和信号传导因子的存在将通过以下方式进行评估： ELISA、微阵列分析（或 RNAse 保护）和蛋白质印迹分析。铅头 ATSDR 有毒物质清单及其诱发或改变的潜力 与免疫反应相关的疾病的发生率需要更好 明白了。这种细胞和分子方法应该确定其机制 Pb 具有免疫调节作用，有助于评估其健康危害和 暴露风险的分子基础。

DESCRIPTION (provided by applicant): The mechanisms by which lead (Pb) alters immune reactivities are multifactorial, both MHC and non-MHC genes are likely involved, in that there appear to be independent effects on T cells, B cells and macrophages, and these effects appear to involve different cytokines and signaling/transcription factors. The long-term goal of this project is to determine the sub cellular mechanisms by which Pb alters lymphocyte development (naive to memory cells) and the activation and reactivity of memory T cells which could influence immunity causing hypo- or hyper-responsiveness. This proposal tests the hypothesis that the heavy metal Pb can alter immune status by biochemical and molecular modulations resulting in a preferential environment for development of type-2 responses, and dependent on the particular type of immune response needed for defense against an infectious agent, cancer or regulation of self-reactive response, this "skewing" may increase pathologies associated with lessened type-] and enhanced lype-2 immune responses. Synergies between chemical, physical and/or emotional stresses can enhance the skewing of immune reactivities toward type-] or type-2 responses; short-term imbalance is needed for appropriate defenses, but long-term imbalance exacerbates pathologies. Thus, an environmental agent such as Pb may alter the balance enough to increase morbidity. Mutant (genetic over-expressing or deficient) H-2d mice will be employed to assess the involvement of specific genes in the "skewing" phenomenon. Specific questions to be addressed are: how Pb alters kinetic production of IFN?gamma; how macrophage reactivities, such as production of ILl 0, ILl 2 or ILl 8, are altered, and whether cellular thiol modifications are involved; whether Pb "skewing" can be achieved with T cells specific only to OVA or whether T cells with self-reactivity (or metal-related specificities) are needed, whether B cells or a particular type of T cell subset (e.g., NK-like T cells) are required and within what particular cytokine environment; what molecular mechanisms are involved with the IL-4 reactivities of T cells; and what cells are responsible for the type-2 environment induced by Pb. Cell types will be assayed by flow cytometry and immunofluorescence microscopy. The presence of cytokines and signaling factors will be assessed by ELISA, microarray analysis (or RNAse protection) and western analyses. Pb heads the ATSDR list of toxic substances and its potential to induce or modify incidence of diseases associated with immune reactivities needs to be better understood. This cellular and molecular approach should identify the mechanisms by which Pb is immunomodulatory and assist evaluation of its health hazard and the molecular basis for the risks in exposure.