Restricted usage of T-cell receptor Vγ–Vδ genes and expression of costimulatory molecules in Takayasu’s arteritis

To further investigate the immunological mechanisms involved in Takayasu’s arteritis, we analyzed the T-cell receptor (TCR) Vγ and Vδ gene usage by infiltrating γδ T-cells and the expression of costimulatory molecules B7-1, B7-2, CD40, CD27 ligand (CD27L), CD30L, OX40L in the arterial tissue of a patient with Takayasu’s arteritis. We found that the repertoires of TCR Vγ as well as Vδ gene transcripts of the infiltrating cells were restricted as compared with those of peripheral blood lymphocytes from a patient with Takayasu’s arteritis. This strongly suggests that γδ T-cells as well as αβ T-cells, as we previously reported, were specifically involved in the pathogenesis of Takayasu’s arteritis. We also found that B7-1, B7-2, CD40, CD27L, CD30L, and OX40L were expressed in the arterial tissue, suggesting the roles for these costimulatory molecules in T-cell-mediated vascular injury in Takayasu’s arteritis. Our findings strongly support the involvement of T-cell-mediated immunological mechanisms in the pathogenesis of Takayasu’s arteritis.