title: Molecular basis of cross-reactivity among allergen-specific human T cells: T-cell receptor V alpha gene usage and epitope structure.
abstract: Cross-reactivities between the major grass pollen allergens, at the level of T-cell recognition was examined employing several Lolium perenne I (Lol p I)-specific human T-cell clones. Nine of these Lol p I-specific T-cell clones exhibited cross-recognition of the recombinant Poa pratensis IX (Poa p IX) allergen, rKBG7.2, indicating that these two major antigens of a grass pollen share T-cell epitopes. Furthermore, proliferative responses of two other T-cell clones demonstrated that individual allergens of diverse grass pollens also possess common T-cell epitopes. Examination of the T-cell receptor (TcR) V alpha genes of these T-cell clones indicated that these cloned cells utilized distinct J alpha genes and that nine out of 10 clones possessed V alpha 13 gene. Furthermore, sequence comparisons of several allergenic molecules indicated that this cross-reactivity may be due to the presence of epitope(s) with structure(s) similar to the major T-cell epitope of Poa p IX allergens. Taken together, these results suggest for the first time that the major grass pollen allergens share cross-reacting T-cell epitope(s), and that this cross-reactivity is due to the structural homologies among allergens and restricted usage of TcR V alpha genes.
authors.affiliation: Department of Immunology, University of Manitoba, Winnipeg, Canada.
authors.forename: S S
authors.initials: SS
authors.lastname: Mohapatra
authors.forename: S
authors.initials: S
authors.lastname: Mohapatra
authors.forename: M
authors.initials: M
authors.lastname: Yang
authors.forename: A A
authors.initials: AA
authors.lastname: Ansari
authors.forename: P
authors.initials: P
authors.lastname: Parronchi
authors.forename: E
authors.initials: E
authors.lastname: Maggi
authors.forename: S
authors.initials: S
authors.lastname: Romagnani
mesh_terms: D000485:Allergens / Q000276:immunology*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002455:Cell Division / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D004247:DNA / Q000737:chemistry; D000939:Epitopes / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D006109:Poaceae / Q000276:immunology; D011058:Pollen / Q000276:immunology*; D016133:Polymerase Chain Reaction; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000485:Allergens; D000939:Epitopes; D016693:Receptors, Antigen, T-Cell, alpha-beta; D004247:DNA