Background The significance of specific T cell receptor (TCR) Vβ subtypes and human leucocyte antigen (HLA) class II alleles for the development of allergy to lipocalin allergens such as the major dog allergen Can f 1 is not clear at present.
Objective To characterize the TCR Vβ usage in the Can f 1-specific T cell lines and the HLA class II genotypes of Can f 1-allergic and non-allergic subjects.
Methods T cell lines were induced with recombinant Can f 1 from the peripheral blood mononuclear cells of 12 non-atopic dog owners and 26 dog-allergic patients. Thirteen of the dog-allergic subjects were sensitized to Can f 1. Expression of the TCR Vβ subtypes on CD4+ T cells in the T cell lines was measured by flow cytometry. The subjects were HLA genotyped for DRB1, DQB1 and DPB1 loci.
Results Can f 1-specific T cell lines were obtained from 18 subjects, with either positive (n=8) or negative (n=10) skin prick tests (SPTs) to recombinant Can f 1. The frequency of TCR Vβ5.1+ T cells was significantly higher in the T cell lines of subjects with negative SPTs to the allergen. Moreover, DR4–DQ8 haplotype was over-represented among these subjects.
Conclusion The DR4–DQ8 haplotype and the TCR Vβ5.1+ CD4+ T cells may be protective against allergy to Can f 1.