The goal of this interagency agreement is to provide support of National Toxicology Program (NTP) hazard identification activities targeted toward the prevention of diseases or adverse effects caused by environmental exposure to chemical or physical agents. These cooperative studies continue to improve the risk assessment process by determining quantitatively what constitutes an adverse health effect on the immune system in humans. These studies evaluate unique cohorts of individuals from professions associated with immune-mediated occupational diseases including asthma, contact dermatitis, allergy to mold spores, chronic beryllium disease, allergic rhinitis, silicosis and latex allergy. These cohorts are being studied for a number of endpoints including, impact of genetic polymorphisms on inflammatory disease development and clinical outcomes, and identification of unique immunological biomarkers for disease. The NIOSH Laboratory for Occupational Genomics serves as a resource for obtaining samples from individuals with occupational and occupationally related diseases including chemical-induced contact dermatitis, musculoskeletal disease, chronic beryllium disease, pulmonary fibrosis, chronic obstructive pulmonary disease, HIV infection, occupationally related cancer, neurodegenerative disease, occupational asthma and rhinitis, and silicosis. A major emphasis has been placed on cytokine polymorphisms, especially within the MHC region, as a large number of occupational/environmental diseases are associated with chronic inflammatory responses and, thus, immune responses. Recruitment of subjects exposed to low- and high-molecular weight agents is still ongoing in occupational pulmonary clinics in Canada and Europe. We completed genotyping of MHC region variations (2,360 loci) using Illumina high density single nucleotide polymorphism (SNP) microarray platform. Preliminary analyses comparing LMW-exposed specific inhalation challenge positive and negative groups showed that over 100 SNPs are statistically significantly associated with occupational asthma. Genotyping of SNPs in immune/inflammatory and antioxidant genes will continue in FY09. The Chronic Beryllium Disease (CBD) project investigates the contribution of genetic variations in the MHC region to the development of Be sensitization and CBD. Data has been collected using high density analysis of SN microarray (2,360 loci). An additional project examining the role of genetics in response to vaccination involved 150 healthy children (at age of 1) who visit a university hospital for routine examination. Based on our previous results in adults, IL-1β SNPs have been genotyped, and serum antibody responses to hepatitis B, pneumococcal polysaccharides, diphtheria and tetanus and also serum total IgG (along with subtypes 1-4), IgM and IgA levels have been measured. Ongoing efforts will genotype an additional set of markers in inflammatory and immune genes. We are also investigating the contribution of genetic variability in the immune-inflammatory-antioxidant responses to the development and/or severity of irritant contact dermatitis (ICD) in health care workers. Subject recruitment, sample collection and follow-ups are completed for approximately 350 individuals and recruitment of additional subjects is ongoing. We are currently processing collected samples. An additional aspect of our dermatitis studies will investigate underlying genetic profiles in nickel-sensitized patients, in patients sensitized to weak allergens, and in patients with reactions to more than 3 allergens of the 70 tested on the standard screening series (polysensitized). Comparison will be made to individuals previously enrolled the study of irritant contact dermatitis in health care workers. Individuals who had no irritant contact dermatitis and no history of allergic skin disease based on questionnaire will be selected as controls. Diisocyanates are the leading cause of occupational asthma. To further current understanding of the pathobiology of respiratory disease induced by exposure to diisocyanates in the workplace we are using whole-genome techniques to identify major biological pathways that may serve as targets for biomarker development, disease diagnosis and/or treatment of disease. To fulfill this objective, we have initiated collaborations with extramural partners to investigate the mechanisms of occupational rhinitis in workers exposure to diisocyanates. Nasal mucosal tissue is being obtained from workers that are confirmed as specific inhalation challenge positive to diisocyanate challenge. Nasal cytology will be performed on one sample to examine the cellular inflammation that characterizes this disease. Whole-genome microarrays will then be performed on a second sample to investigate the underlying biology and identify potential targets for biomarker development. Similar studies in diverse worker populations are required to develop biomarkers that may be useful for disease surveillance and diagnosis in geographically and ethnically distinct populations. We are conducting parallel studies in a murine model of diisocyanate-induced rhinitis. Whole-genome microarray studies strongly support a role for allergic immune mechanisms and have identified antibody pathways and chemokine pathways as important mediators of this disease. In addition, we are investigating biomarkers for of toluene diisocyanate (TDI) exposure and asthma. At present, biomarkers for TDI exposure are chemical based, and instrument and labor intensive. They also do not distinguish between exposure to toluene diamine (starting material in the production of TDI) and TDI. We have developed 3 clones that produce monoclonal anti-TDI IgM from TDI vapor exposed mice. We have now conjugated 2,4-TDI and 2,6-TDI to the protein, KLH. Occupational rhinitis is a chronic inflammatory disease of the upper respiratory tract that is present in greater than 90% of workers with occupational asthma. A cohort of chronic rhinosinusitis patients is being evaluated for subjects with allergies to molds. One hundred and one patients have been analyzed by skin prick testing and Immunocap analysis. Serum sample have been analyzed for IgE to perennials, grass, weeds, trees and indoor molds. As there is currently a lack of information on dry fungal aerosol exposures, we are utilizing aerosols from several organisms to investigate the consequences of dry fungal aerosol exposures in a rodent model. Germination (viability) has been suggested to enhance the adverse health effects of fungal exposure. Methods for dry fungal aerosol delivery by pharyngeal insufflation in respitose have been developed. Currently, animals are being exposed to two species of Aspergillus, and the extent of lung inflammation and systemic antibody responses are being charcterized. A related project includes work to characterize the role of terrelysin as a marker of Aspergillus terreus exposure. Monoclonal antibodies have been developed to a hemolytic extract prepared from Aspergillus terreus. These antibodies are being characterized as to antigen recognition and their utility as immunodiagnostic reagents for exposure and biological effects. We have cloned and are producing recombinant terrelysin as a reagent for these assays. Mercaptobenzothiazole (MBT) and zinc dialkyldithiocarbamates (specifically, diethyldithiocarbamates, ZDEC) are commonly found in latex medical and non-medical gloves, as well as many other latex products. These compounds can be found in gloves at high levels and cause significant rates of allergic contact dermatitis. Studies into the chemical mechanisms of these latex allergens was completed and published in FY08. This work has resulted in a new project that will use both in vivo and in vitro methods to distinguish prohaptens from haptens. An analytical screening method developed for measurement of allergenic chemical accelerators(thiocarbamates, thiurams and mercaptobenzothiazole) in latex and nitrile gloves has passed the final ASTM round-robin testing and been submitted for balloting as an ASTM standard method. In addition, a new direct probe GC-MS chemical speciation method has been developed. Finally, ongoing studies are identifying and quantifying the reaction products of gas-phase compounds present in the indoor environment, especially dicarbonyls, and investigating immunotoxic and hypersensitivity effects of these reaction products in both in vitro and in vivo models. The Vitrocell in vitro model is currently being used to expose lung cells to the gas-phase alpha-terpineol/ozone reaction products. To screen for potential adverse health effects caused by VOC exposure, real-time PCR based pathway-focused gene expression profiling has been conducted on the RNA isolated from exposed cells.
