Definitive separation of graft-versus-leukemia- and graft-versus-host-specific XXXX + T cells by virtue of their receptor beta loci sequences.

@entity11112 @entity1778 @entity404 @entity2902
Although graft-versus-host (GVH) disease (GVHD) is usually associated with graft versus @entity1778 (GVL), GVL can occur in the absence of clinical GVHD. There is evidence to suggest that GVL and GVH are mediated by different clones of T cells. The objective of this study was to identify the two types of T cells based on their receptor sequences. To this end we used irradiated nonleukemic cells from recipients as stimulator cells in a primary mixed leukocyte reaction (MLR). The activated @entity404 (+) donor T cells that expressed @entity2902 were purified by cell sorting. To prepare GVL-specific T cells, alloreactive T cells in the primary MLR were first depleted with an anti- @entity2902 immunotoxin. The remaining T cells had negligible alloreactivity in a secondary MLR. The allodepleted cells were then stimulated by using purified @entity1778 cells from the same individual as stimulator cells, and the @entity2902 (+)-activated cells were purified by cell sorting. The GVL- and GVH-specific T cells were analyzed for their T cell receptor (TCR) clonality by using anchored RT-PCR of all the @entity11112 locus complementarity-determining region 3 (CDR3) sequences. By comparing @entity11112 CDR3 sequences from transformed bacterial colonies, we were able to demonstrate that T cells mediating GVH were different from those mediating GVL in each of the eight HLA-mismatched and one HLA-matched donor/recipient pairs. By using the appropriate @entity11112 CDR3-specific primers and probes, the GVH- and GVL-specific clones were monitored in a recipient undergoing an allogeneic stem cell transplant from her HLA-matched related donor.
