Tracking human contact allergens: from mass spectrometric identification of peptide-bound reactive small chemicals to chemical-specific naive human T-cell priming.
Modification of proteins by reactive small chemicals is a key step in the activation of chemical-specific T cells in allergic contact dermatitis (ACD). However, an integrated approach to characterize both the precise nature of chemically modified proteins and the chemical-specific T cells is currently lacking. Here, we analyze the molecular conditions for adduct formation of the strong human contact sensitizer 2,4-dinitrochlorobenzene (DNCB) and its water-soluble form, 2,4-dinitrobenzenesulfonic acid (DNBS), with both an all amino acid-containing model peptide (± Cys) and the protein human serum albumin (HSA). Mass spectrometric detection and quantification revealed thiol-dependent peptide adduct formation at all pH values found in human skin layers. Highest modification rates were obtained with DNBS. Accordingly, DNBS- but not DNCB-modified human immature dendritic cells (iDC) induced in vitro primary human T-cell responses as did 2,4,6-trinitrobenzenesulfonic acid-modified iDC as measured by dinitrophenyl (DNP)- and trinitrophenyl (TNP)-specific T-cell proliferation and interferon gamma (IFN-γ) production in CD4(+) and CD8(+) T-cell subsets. Moreover, DNP-modified HSA protein effectively induced primary T-cell responses when processed by iDC. Thus, an integrated approach that combines efficient skin-related in chemico coupling analyses with an in vitro T-cell priming assay can be used to predict in vivo reactions of chemical contact allergens with extracellular and cellular proteins. This strategy supports the development of chemical-specific in vitro assays that are urgently required in predictive hazard identification and risk assessment of allergenic and nonallergenic chemicals.
Dietz
Lisa
L
Laboratory of Immunology & Proteomics, Department of Dermatology and University Medical Center Mannheim, University of Heidelberg, 68167 Mannheim, Germany.
Esser
Philipp R
PR
Schmucker
Sonja S
SS
Goette
Irina
I
Richter
Anne
A
Schnölzer
Martina
M
Martin
Stefan F
SF
Thierse
Hermann-Josef
HJ
D000485:Allergens / Q000737:chemistry / Q000378:metabolism*; D001557:Benzenesulfonates / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D003877:Dermatitis, Contact; D004137:Dinitrochlorobenzene / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D010446:Peptide Fragments / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*
D000485:Allergens; D001557:Benzenesulfonates; D004137:Dinitrochlorobenzene; D010446:Peptide Fragments; C001073:2,4-dinitrobenzenesulfonic acid