title: Identification and validation of shrimp-tropomyosin specific CD4 T cell epitopes.
abstract: BACKGROUND
  Shellfish allergy is an immune-mediated adverse reaction to allergenic shellfish and is responsible for significant morbidity and mortality. CD4 T cell responses play an important role in the pathophysiological mechanisms of sensitization and in production of IgE.
  
  
  OBJECTIVE
  We sought to identify and validate CD4 T cell shrimp tropomyosin-derived epitopes and characterize CD4 T cell responses in subjects with a clinical history of shellfish allergy.
  
  
  METHODS
  Using an in vitro MHC-peptide binding assay, we screened 91 overlapping peptides and identified 28 epitopes with moderate and strong binding capacities; 3 additional peptides were included based on MHC binding prediction score. These peptides were then examined in proliferation and cytokine release assays with T cells from allergic subjects.
  
  
  RESULTS
  17 epitopes restricted to DRB(∗)01:01, DRB1(∗)03:01, DRB1(∗)04:01, DRB1(∗)09:01, DQB1(∗)02:01, DQB1(∗)03:02 and DQB1(∗)05:01 alleles were identified and validated by both the MHC binding and the functional assays. Two peptides showed specificities to more than one MHC class II allele. We demonstrated that these peptides exert functional responses in an epitope specific manner, eliciting predominantly IL-6 and IL-13.
  
  
  CONCLUSIONS
  The identified epitopes are specific to common MHC class II alleles in the general population. Our study provides important data for the design of peptide-based immunotherapy of shrimp-allergic patients.
authors.affiliation: ARUP Institute for Clinical and Experimental Pathology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84108, United States. Electronic address: eugene.v.ravkov@aruplab.com.
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Ravkov
authors.forename: Igor Y
authors.initials: IY
authors.lastname: Pavlov
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Martins
authors.forename: Gerald J
authors.initials: GJ
authors.lastname: Gleich
authors.forename: Lori A
authors.initials: LA
authors.lastname: Wagner
authors.forename: Harry R
authors.initials: HR
authors.lastname: Hill
authors.forename: Julio C
authors.initials: JC
authors.lastname: Delgado
mesh_terms: D000485:Allergens / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D016022:Case-Control Studies; D016207:Cytokines / Q000096:biosynthesis; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D005512:Food Hypersensitivity / Q000276:immunology / Q000378:metabolism; D006680:HLA Antigens / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D033561:Penaeidae / Q000276:immunology*; D011485:Protein Binding; D014335:Tropomyosin / Q000276:immunology*
chemical_list: D000485:Allergens; D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D006680:HLA Antigens; C408902:MHC binding peptide; D009842:Oligopeptides; D014335:Tropomyosin
keywords: MFI; mean fluorescence intensity