Mechanisms of Pesticide Neuro- and Immunotoxicity in Children

生活在农业社区的儿童暴露在杀虫剂和过敏原的混合物中，这可能会对免疫和神经毒性产生不利影响。我们的目标是阐明这些对呼吸系统疾病和神经发育不利影响的潜在机制。我们将：1)检测杀虫剂(毒死蜱和甘露醇)和屋尘螨变应原(Der Pl)单独和联合作用对Th1/Th2细胞因子产生的影响；2)确定农药和变应原暴露是否在体外对儿童和成人淋巴细胞中细胞因子的表达产生不同影响；3)建立一种新的基于机理的酶促成人淋巴细胞“神经病变靶标酯酶”(NTE)的检测方法，4) 确定人类从出生到成年期不同年龄NTE活性的个体发育变化；5)确定儿童和成人淋巴细胞中NTE对已知NTE抑制剂以及我们萨利纳斯山谷农业社区常见杀虫剂的敏感性。 该项目将利用我们从CHAMACOS孕妇和儿童队列中提取的大量生物样本库。我们将使用人类细胞的体外培养来检测单独和联合暴露于杀虫剂和过敏原对细胞因子反应的影响。细胞因子的剂量反应将由Taqman？实时定量聚合酶链式反应、细胞内细胞因子的流式细胞仪检测和酶联免疫吸附试验。利用这些方法，我们将阐明农药免疫毒性的机制，这可能与儿童呼吸系统疾病有关。 我们将在神经母细胞瘤细胞系和人类中检测NTE活性在神经毒性中的作用。 使用一种基于与细胞靶标(溶血磷脂)相互作用的新方法的淋巴细胞。该方法可能在评估农药中毒和化学战中的不良健康后果以及了解儿童农药暴露的神经行为影响机制方面具有重要的临床应用价值。 这些研究将有助于为今后有关允许儿童和孕妇接触杀虫剂的政策决定提供信息。

Children living in agricultural communities are exposed to mixtures of pesticides and allergens, which may have adverse immunologic and neurotoxic effects. We aim to elucidate the potential mechanisms for these adverse effects on respiratory disease and neurodevelopment. We will: 1) examine the in vitro effects of pesticides (chlorpyrifos and maneb) and house dust mite allergen (Der pl), alone and in combinations, on the production of Thl/Th2 cytokines; 2) determine whether pesticide and allergen exposures differentially affect cytokine expression in lymphocytes of children versus those of adults in vitro; 3) establish a new mechanism-based enzymatic assay for "neuropathy target esterase" (NTE) in human adult lymphocytes, 4) determine the ontogenetic changes in NTE activity in humans at different ages from birth to adulthood; 5) determine the sensitivities of NTE in children and adult lymphocytes to known NTE inhibitors, as well as to pesticides commonly found in our agricultural community in the Salinas Valley. This project will take advantage of our large repository of biological samples from the CHAMACOS cohort of pregnant women and children. We will use in vitro cultures of human cells to examine the effects of individual and combined exposures to pesticides and allergens on cytokine response. Cytokine dose responses will be determined by Taqman? realtime PCR, flow cytometric detection of intracellular cytokines, and ELISA. Using these methods, we will elucidate mechanisms of pesticide-induced immunotoxicity, which may be related to respiratory disease in children. We will examine the role of NTE activity in neurotoxity in a neuroblastoma cell line and in human lymphocytes using a new method based on interaction with a cellular target (lysophospholipids). This method may have important clinical uses in assessing adverse health outcomes in cases of pesticide poisonings and chemical warfare, and in understanding the mechanism of neurobehavioral effects of pesticide exposure in children. These studies will help to inform future policy decisions regarding allowable pesticide exposure to children and pregnant women.