Effects of Immunotherapy on the Distribution and Clonality of TCR Vγ and Vδ Subfamily T Cells in Allergic Rhinitis Patients

The aim of this study was to investigate the changes in the peripheral specific IgE level, distribution of TCR Vg and Vd subfamily T cells and mRNA expressions of TCR Vg I-III following specific immunotherapy (SIT) with house-dust-mite extract in allergic rhinitis (AR) patients. Ten AR patients undergoing SIT with house-dust-mite extract for 1 year were recruited. Quantitative analysis of immunofluorescence was performed to detect the serum specific IgE (sIgE) level before and after SIT; RT-PCR-genescan analysis was employed to detect the mRNA expressions of TCR Vg (I-III) and Vd (1-8) in the peripheral mononuclear cells followed by analysis of T cell clonality. Real-time quantitative PCR was applied to detect the expressions of TCR Vg I-III genes. Ten healthy volunteers served as controls. For AR patients, SIT treatment could improve the symptoms, but the serum sIgE level was not markedly decreased. Before SIT, the expressions of TCR Vg I-III gene were similar between AR patients and controls (P>0.05) but markedly decreased after SIT in AR patients (P<0.05 in TCR VgI and VgII). The expressions of TCR Vd (1-8) before and after SIT were 5.3±0.82 and 4.9±0.57, respectively, and that in healthy controls was 5.2±1.40. Vd1, 2, 3 and 6 were the most common genes found in these patients. Significant difference in the TCR Vd6 subfamily T cells was found between the two groups. Polyclonal or biclonal proliferation was found in the T cells of patients before SIT and in healthy controls, but oligoclonal proliferation in only 1 subject before SIT. After SIT, the proportion of patients with oligoclonal proliferation of T cells (6/10) was markedly increased (P<0.05). SIT for 1 year could alter the expressions of TCR Vg I-III genes, the distribution of TCR Vg and Vd T cells and the ways in which T cells proliferate. The early improvement of symptoms following immunotherapy might not be related to the serum sIgE content in AR patients, but associated with the TCR gd T cells, especially the TCR V d6 T cells.