Objective: To investigate the distribution and clonality of T cell receptor (TCR) Vγ and Vδ subfamily in peripheral blood of patients with allergic rhinitis before and after 1 year treatment with immunotherapy.
Methods: The specific IgE and the complementary determinant region 3 (CDR3) of TCR V γ (I-III) and Vδ(1-8) subfamily genes in mononuclear cells were amplified from 10 effective cases of allergic rhinitis before and after 1 year treatment with immunotherapy, to observe the distribution and utilization of TCR Vγ and Vδ repertoire. The positive PCR products were further labeled with RT-PCR and analyzed by gene scan technique to determine the CDR3 size and evaluate the clonality of the detectable TCR Vγ and Vδ T cells. Peripheral blood of 10 healthy adults served as controls.
Results: All symptoms were significantly improved after 1 year specific immunotherapy, but no changes were seen in specific IgE [(22.89 ± 9.60) kU/L before treatment, (19.62 ± 7.63) kU/L after treatment, Z = 1.051, P > 0.05]. No statistically significant differences of expression levels of the TCR Vγ I-III subfamily genes were found between patients with allergic rhinitis normal control group (t value were -0.679, -0.516, -0.808, all P > 0.05), but significantly decreased after 1 year treatment. There were statistically significant differences of expression levels of the TCR VγI-II subfamily genes before and after treatment (t value were -2.904, -2.217, all P < 0.05). 5.30 ± 0.82, 4.90 ± 0.57 and 5.20 ± 1.40 out of TCR Vδ (1-8) subfamilies were selectively expressed in T cells in patients with allergic rhinitis before and after 1 year treatment and normal control group, predominantly for TCR Vδ 1, 2, 3 and 6. The TCR Vδ 6 subfamily was found to have statistically significant differences in these groups (Fisher's Exact Test, P < 0.05). Compared with the normal control group and the allergic rhinitis group before treatment, a significant higher frequency of Vδ 6 oligoclonal was identified in T cells in patients with allergic rhinitis after 1 year treatment.
Conclusions: There was difference in the expression levels of the TCR Vγ I-III subfamily genes and distribution and clonality of TCR Vγ and Vδ subfamily T cells in peripheral blood of patients with allergic rhinitis before and after 1 year treatment. Specific immunotherapy can be effective in alleviation of the symptom in patients with allergic rhinitis during the early stage, possibly by inducing TCR γδ T cells, especially the TCR Vδ6 subfamily, and possibly no significant relativity between symptom and specific IgE.