Association of T-cell receptor Vβ haplotypes with dry skin in DS-Nh mice

Summary Background.  Although dry skin and T cell-dependent disease exacerbation are characteristic features of atopic dermatitis (AD), the involvement of T cells in the development of dry skin remains unclear. Aims.  We aimed to elucidate the role of T cells in the development of dry skin in DS-Nh mice as a model for AD, and to evaluate this skin condition pharmacologically. Methods.  We prepared DS-Nh mice harbouring a T-cell receptor (TCR)Vβa haplotype with a central deletion in the TCRBV gene segments, and mice harbouring a TCRVβb haplotype without any deletion. We analysed the TCRVβ chain usage and cytokine response to antimouse CD3 monoclonal antibodies in the splenocytes from the two mouse substrains. Transepidermal water loss (TEWL) was measured, and histochemical examination of these mice was carried out. Finally, a pharmacological analysis using loratadine was also performed to evaluate the features of spontaneous dry skin in DS-Nh mice as a model of AD. Results.  Although the deletion of TCRBV gene segments in the TCRVβa haplotype yielded different representations of each TCRVβ mRNA, this deletion did not evoke distinct cytokine profiles in the splenocytes compared with those of mice with the TCRVβb haplotype. Furthermore, our results indicated that the onset of dry skin occurred earlier in mice with TCRVβb than in those with TCRVβa. Pharmacologically, AD-like dry skin in DS-Nh with TCRVβb mice is susceptible to an H1 blocker. Conclusions.  A specific lymphocyte subpopulation bearing T-cell receptors may be responsible for loratadine-responsive dermatitis in DS-Nh mice.