With a known antigen and an accessible target organ, chronic beryllium disease (CBD) serves as an important organ-specific, immune-mediated disease. CBD results from beryllium exposure and is associated with the accumulation of beryllium-specific, Thi-type cytokine-secreting CD4* T cells in the lung. Previous studies have helped identify the genetic and functional importance of the T cell antigen receptor (TCR) and HLA-DP2 in CBD immunopathogenesis. Despite the advances in our understanding of the immunopathogenesis of beryllium-induced disease, how beryllium binds to the major histocompatibility complex class 11 (MHCII) molecule and is subsequently recognized by beryllium-specific 004* T cells remains unknown. Recently, the crystallization of HLA-DP2 by our group has revealed a potential beryllium binding site to glutamic acid residues at amino acid positions in the p-chain and the peptide backbone. Data suggest that beryllium directly binds to HLA-DP2 and that particular peptides are required to complete the apTCR ligand. The central goal of this revision of Project 1 is to characterize the beryllium antigen responsible for CD4* T cell activation. A series of experiments has been designed to identify the HLA-DP2 peptide epitopes required to complete the apTCR ligand and activate beryllium-specific CD4* T cells. Using established methods and cell model systems, specific experiments will: 1) Define the sequence and motif of peptides that bind to HLA-DP2 and determine the binding affinities of those peptides, 2) Delineate which of the identified HLA-DP2 binding peptides in the presence of beryllium salt allow recognition of beryllium by antigen-specific TCRs, 3) Identify and characterize the TCRs expressed by the subset of T cells found in the bronchoalveolar lavage (BAL) of patients with CBD that respond to the different peptide sets identified, and 4) Determine whether HLA-DP2/peptide/beryllium complexes can be used to identify and characterize beryllium-reactive CD4+T cells in the blood and BAL of CBD patients, as a potential biomarker of disease and disease progression. This translational study is multidisciplinary, assembling immunologists, biochemists, HLA structural biologists, and physician-scientists to define the precise nature of the MHCII/Beryllium/Peptide/TCR relationship in CBD. Project 1 integrates with Project 2 by providing functional basis for genetic epidemiologic discoveries, and with Project 3 by testing immune biomarker outcome measures in parallel. The results will improve the understanding of metal antigen structure/function and result in data to support the use of peptide tetramers as clinical biomarkers.

Public Health Relevance

This project will explain how a metal can interact with proteins to trigger an abnormal immune response in humans;identify how human T lymphocytes recognize an antigen composed of metal plus native peptides; pioneer the use of peptide multimers as clinical biomarkers that can trace the pathogenic T lymphocytes that produce granulomatous disease in a human, immune-mediated, environmentally-induced disorder.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Program Projects (P01)
Project #
5P01ES011810-09
Application #
8382595
Study Section
Special Emphasis Panel (ZES1-TN-J)
Project Start
2012-05-01
Project End
2014-04-30
Budget Start
2012-05-01
Budget End
2013-04-30
Support Year
9
Fiscal Year
2012
Total Cost
$315,320
Indirect Cost
$108,153
Name
University of Colorado Denver
Department
Type
DUNS #
041096314
City
Aurora
State
CO
Country
United States
Zip Code
80045
Falta, M T; Tinega, A N; Mack, D G et al. (2016) Metal-specific CD4+ T-cell responses induced by beryllium exposure in HLA-DP2 transgenic mice. Mucosal Immunol 9:218-28
Fontenot, Andrew P; Falta, Michael T; Kappler, John W et al. (2016) Beryllium-Induced Hypersensitivity: Genetic Susceptibility and Neoantigen Generation. J Immunol 196:22-7
Tooker, Brian C; Ozawa, Katherine; Newman, Lee S (2016) CpG promoter methylation status is not a prognostic indicator of gene expression in beryllium challenge. J Immunotoxicol 13:417-27
Li, Li; Hamzeh, Nabeel; Gillespie, May et al. (2015) Beryllium increases the CD14(dim)CD16+ subset in the lung of chronic beryllium disease. PLoS One 10:e0117276
Tooker, Brian C; Brindley, Stephen M; Chiarappa-Zucca, Marina L et al. (2015) Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway. J Immunotoxicol 12:181-7
McKee, A S; Mack, D G; Crawford, F et al. (2015) MyD88 dependence of beryllium-induced dendritic cell trafficking and CD4⁺ T-cell priming. Mucosal Immunol 8:1237-47
Clayton, Gina M; Wang, Yang; Crawford, Frances et al. (2014) Structural basis of chronic beryllium disease: linking allergic hypersensitivity and autoimmunity. Cell 158:132-42
Li, L; Huang, Z; Gillespie, M et al. (2014) p38 Mitogen-Activated Protein Kinase in beryllium-induced dendritic cell activation. Hum Immunol 75:1155-62
Mack, Douglas G; Falta, Michael T; McKee, Amy S et al. (2014) Regulatory T cells modulate granulomatous inflammation in an HLA-DP2 transgenic murine model of beryllium-induced disease. Proc Natl Acad Sci U S A 111:8553-8
Bowerman, Natalie A; Falta, Michael T; Mack, Douglas G et al. (2014) Identification of multiple public TCR repertoires in chronic beryllium disease. J Immunol 192:4571-80

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