Mechanisms of Pesticide Neuro- and Immunotoxicity in Children

生活在农业社区的儿童暴露于杀虫剂和过敏原的混合物，这可能会产生不良的免疫和神经毒性影响。我们的目的是阐明这些对呼吸系统疾病和神经发育的不良影响的潜在机制。我们将：1）研究杀虫剂的体外效应（毒死蜱和代森锰）和屋尘螨变应原（Der pl）单独和组合对Th 1/Th 2细胞因子产生的影响; 2）确定杀虫剂和变应原暴露是否在体外对儿童淋巴细胞中的细胞因子表达与成人淋巴细胞中的细胞因子表达有差异; 3）建立了一种新的基于机制的成人淋巴细胞中“神经病靶标酯酶”（NTE）的酶促测定法，4） 确定从出生到成年的不同年龄段的人类NTE活性的个体发生变化; 5）确定儿童和成人淋巴细胞对已知NTE抑制剂的NTE敏感性，以及对萨利纳斯山谷农业社区中常见的农药的敏感性。 该项目将利用我们从CHAMACOS孕妇和儿童队列中获得的大量生物样本库。我们将使用体外培养的人类细胞，以检查个人和联合暴露于农药和过敏原对细胞因子反应的影响。细胞因子剂量反应将通过Taqman？实时PCR、细胞内细胞因子的流式细胞术检测和ELISA。利用这些方法，我们将阐明农药诱导的免疫毒性的机制，这可能与儿童呼吸系统疾病。 我们将研究NTE活性在神经母细胞瘤细胞系和人类神经毒性中的作用。 使用基于与细胞靶点（溶血磷脂）相互作用的新方法检测淋巴细胞。这种方法可能有重要的临床用途，在评估农药中毒和化学战的情况下，不良的健康后果，并在了解农药暴露的儿童神经行为影响的机制。 这些研究将有助于为今后关于儿童和孕妇允许接触农药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.