MOLECULAR ANALYSIS OF T-CELL RECEPTOR REPERTOIRE IN BONE-MARROW TRANSPLANT RECIPIENTS - EVIDENCE FOR OLIGOCLONAL T-CELL EXPANSION IN GRAFT-VERSUS-HOST DISEASE LESIONS

We have analyzed the T-cell receptor (TCR) V beta repertoire using pol ymerase chain reaction (PCR) in a cohort of eight patients receiving a llogeneic bone marrow transplantation (BMT) from related and unrelated donors at the City of Hope, Results of PCR studies from graft-versus- host disease (GVHD) skin lesions show a bias in the usage of TCR V bet a families, whereas examination of peripheral blood (PB) withdrawn at the same time did not reveal a similar phenomenon, In one such family, TCR V beta 2 is predominantly expressed in 7 of 7 biopsy specimens ex amined, V beta 2 TCR expression from these patients was analyzed more extensively using a combination of individual TCR gene cloning, follow ed by sequence analysis, We found evidence of oligoclonal expansion of single V beta 2-bearing TCRs in GVHD lesions, and in the PB of some p atients after diagnosis of GVHD. In contrast, GVHD-negative biopsy sam ples showed no evidence for clonotypic TCR amplification, Sequence-spe cific TCR CDR3 region probes were derived from analysis of the predomi nant expressed TCR in GVHD lesions, and used to probe Southern blots o f amplified V beta 2 TCR mRNA from PB and tissue from BMT recipients a nd their respective donors. In most cases the probes are highly specif ic in detecting TCR expression from GVHD lesions alone, although in se veral instances expression could be detected in PB after GVHD diagnosi s. These data provide supporting evidence for the hypothesis that acut e GVHD is associated with expansion of T-cell clones expressing antige n-specific TCRs that may contribute to the disease pathology. (C) 1996 by The American Society of Hematology.