Vβ spectratype analysis reveals heterogeneity of CD4+ T-cell responses to minor histocompatibility antigens involved in graft-versus-host disease:: Correlations with epithelial tissue infiltrate

Lethal graft-versus-host disease (GVHD) can be induced after hematopoietic stem cell transplantation between major histocompatibility complex-matched murine strains expressing multiple minor histocompatibility antigen (miHA) differences. In the C57BL/6By (B6) --> C.B10-H2(b)/LiMcdJ (BALB.B) irradiation model, both CD4(+) and CD8(+) donor T cells can mediate lethal GVHD, whereas in the B6 --> CXB-2/By (CXBE) model, in which the recipient expresses a subset of BALB.B miHA, only the CD8(+) T cells are lethal. Phenotypic analysis of CD4(+) T cells collected from the thoracic duct lymphocyte pool of recipient mice had indicated expansion of the donor T-cell receptor V beta6-9 families in BALB.B recipients, and only V beta7 and V beta9 populations in CXBE mice. CDR3-size spectratyping, used to further analyze these responses, revealed overlapping oligoclonal expansion of V beta4, V beta6-10, and V beta 12-14 families in both BALB.B and CXBE recipients injected with host-presensitized B6 T cells. In addition, the B6 --> BALB.B CD4(+) T-cell response appeared to involve the recognition of unique BALB.B-specific miHA, indicated by additional skewing of V beta2 and V beta 11 families. On the other hand, the B6 --> CXBE strain combination exhibited unique skewing of the V beta 16 and V beta 18 families. Immunohistochemical staining of lingual epithelial sections from BALB.B recipients of naive B6 CD4(+) T cells correlated with the involvement of several of the spectratype-skewed V beta families in GVHD lesions. Furthermore, magnetic cell separation techniques were used to positively select the spectratype-skewed V beta families from the donor B6 CD4(+) T cells; the former were found to have significant GVHD potential upon transplantation into lethally irradiated BALB.B recipients. In contrast, mice that received transplants from the unskewed V beta families all survived with minimal symptoms of GVHD. Taken together, these results demonstrate that the expansion of particular V beta families, as identified by spectratype analysis, correlates with the induction and pathogenesis of lethal GVHD.