2004 Progress Report: Environmental Factors in the Etiology of Autism; Cell Activation/Signaling Core

EPA Grant Number: R829388C002
Subproject: this is subproject number 002 , established and managed by the Center Director under grant R829388
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: CECEHDPR - University of California at Davis Center for the Study of Environmental Factors in the Etiology of Autism
Center Director: Pessah, Isaac N.
Title: Environmental Factors in the Etiology of Autism; Cell Activation/Signaling Core
Investigators: Van de Water, Judith , Ashwood, Paul
Institution: University of California - Davis
EPA Project Officer: Hahn, Intaek
Project Period: September 30, 2001 through September 29, 2002
Project Period Covered by this Report: September 30, 2003 through September 29, 2004
RFA: Centers for Children's Environmental Health and Disease Prevention Research (2001) RFA Text |  Recipients Lists
Research Category: Health , Children's Health , Health Effects

Objective:

Profile serologic samples from autistic and matched control children collected from Research Projects I (Environmental Epidemiology), from Project II (Animal Models), and tissue culture experiments performed in Project III (Molecular/Cell Mechanisms).

  • To define the blood levels of key neurotrophins and neuropeptides by ELISA or recycling immunoaffinity chromatography
  • To ascertain what tissue-specific antibodies are found in sera of patients with autism using a variety of neuronal antigens by immunoblot. Using patient sera, also perform immunohistochemical analysis of brain tissue from autistic patients and controls. Similar studies will be performed during the generation of animal models in Project II.
  • Using our brain tissue from autistic patients solicited through the M.I.N.D. Institute’s collaboration with the Autism Tissue Program of the National Alliance for Autism Research, screen for the presence of differentially expressed antigens as recognized by patient sera. Also of importance is the determination of existing in situ deposits of antibody in the brain of patients (when available).
  • To develop a protein array derived from a brain cDNA library for screening with patient sera for any unknown antigens or receptors found bound by antibodies from patients with autism.

Progress Summary:

We are currently setting up a luminex bead-based system to profile the neurotrophins and neuropeptides in plasma. We continue to use protein extracts from different human brain regions as well as fetal and adult brain to perform Western blot analysis on sera from the mothers of and children with autism.Using extracts from the hypothalmus, we have analyzed 29 patients and 13 typically developing controls thus far and have observed 2 bands, B and M, that are present only patients and not controls. In addition, band B is present in 38% (11/29) of patients and only 7% (1/13) of controls. We continue to screen patients against the hypothalamus as well as several other regions of the brain.

Immunohistochemical analysis is also currently underway for each region of the brain for children with autism as well as TD controls. To date, our pediatric data suggests that while plasma from children with autism does not contain significant antibodies to fetal brain, several subjects to show reactivity against various regions of the brain. Preliminary data from the Western blot studies suggest that in hypothalmus, there is one band that appears in approximately 50% of patients and no controls.

We are also using sera from patients with autism and controls to examine brain sections from Rhesus macaques for antibodies to neural tissue. Thus far, we have seen staining of what appear to be the golgi II cells in the cerebellum in all ASD patients tested and none of the controls. We will continue to screen sera from patients to determine the frequency of reactivity in the cerebellum as well as other defined regions of the brain. Moreover, we will use co-localization techniques to definitively identify the target cells.

We have begun cytokine analysis of our stimulation assays using the newly developed multi-analyte bead system from luminex . This system allows us to measure several cytokines simultaneously for less cost per sample. The preliminary data is shown in Figures 4-6. Thus far, we have tested the response to PHA and tetanus toxoid as a recall antigen using PMBC from 16 patients with ASD and 15 typically developing controls. While there was no difference in the media or baseline levels of any cytokine tested, we did note a significant reduction in the PHA stimulation of GM-CSF (p=0.027) and IL-12 (p=0.006), and an elevation in IL-13 (p=0.04) in the ASD group. However, when the PBMC were challenged with a tetanus toxoid recall antigen, the patients with ASD produced significantly less IFN-, IL1-, IL-10, TNF-, IL-6, and IL-12 than the typically developing controls. This preliminary data suggests a difference in the response of patients with ASD to PHA and a vaccine recall antigen, tetanus toxoid. A reduction in the serologic response to tetanus has also been noted by our laboratory in an earlier study.

We were originally slated to use RAGE analysis to look at tyrosine kinase usage. However, we now have access to a luminex-based assay that will allow us to measure actual protein production in a minimal sample amount.

Journal Articles:

No journal articles submitted with this report: View all 5 publications for this subproject

Supplemental Keywords:

RFA, Health, Scientific Discipline, PHYSICAL ASPECTS, ENVIRONMENTAL MANAGEMENT, Health Risk Assessment, Chemistry, Risk Assessments, Susceptibility/Sensitive Population/Genetic Susceptibility, Disease & Cumulative Effects, Physical Processes, Children's Health, genetic susceptability, Biology, Risk Assessment, chemical exposure, neurotoxic, xenobiotics, biomarkers, epidemiology, gene-environment interaction, neurodevelopment, pesticides, exposure, halogenated aromatics, children, neurobehavioral, neurodevelopmental, neurotoxicity, etiology, susceptibility, human exposure, neurobehavioral effects, autism, biological markers, mechanisms, exposure assessment, neurological development, biomarker, synergistic interactions

Progress and Final Reports:

Original Abstract
  • Final

  • Main Center Abstract and Reports:

    R829388    CECEHDPR - University of California at Davis Center for the Study of Environmental Factors in the Etiology of Autism

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R829388C001 Environmental Factors in the Etiology of Autism; Analytic Biomakers (xenobiotic) Core
    R829388C002 Environmental Factors in the Etiology of Autism; Cell Activation/Signaling Core
    R829388C003 Environmental Factors in the Etiology of Autism; Molecular Biomakers Core
    R829388C004 Environmental Factors in the Etiology of Autism; Childhood Autism Risks from Genetics and the Environment (The CHARGE Study)
    R829388C005 Environmental Factors in the Etiology of Autism; Animal Models of Autism
    R829388C006 Environmental Factors in the Etiology of Autism; Molecular and Cellular Mechanisms of Autism