Distribution and Clonality of the V alpha and V beta T-Cell Receptor Repertoire of Regulatory T Cells in Leukemia Patients With and Without Graft Versus Host Disease

摘要

Graft versus host disease (GVHD) is the main complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Recent data indicated that regulatory T (Treg) cells might relate to GVHD, and such functions might be mediated by certain T-cell receptor (TCR) subfamily of Treg cells. Thus, we analyzed the distribution and clonality of the TCR V alpha and V beta repertoire of Treg cells from leukemia patients with and without GVHD after allo-HSCT. Numerous TCR V alpha subfamilies, including V alpha 1, V alpha 9, V alpha 13, V alpha 16-19, and V alpha 24-29, were absent in Treg cells after allo-HSCT. The usage numbers for the TCR V alpha and V beta subfamilies in Treg cells from patients without GVHD appeared more widely. The expression frequencies of V alpha 10 or V alpha 20 between both groups were significantly different. Moreover, the expression frequency of TCR V beta 2 subfamily in patients without GVHD was significantly higher than that in patients with GVHD. Oligoclonally expanded TCR V alpha and V beta Treg cells were identified in a few samples in both groups. Restricted utilization of the V alpha and V beta subfamilies and the absence of some important TCR rearrangements in Treg cells may be related to GVHD due to a lower regulating function of Treg subfamilies.