Unraveling Graft-versus-Host Disease and Graft-versus-Leukemia Responses Using TCR Vβ Spectratype Analysis in a Murine Bone Marrow Transplantation Model

Abstract

The optimum use of allogeneic blood and marrow transplantation (BMT) as a curative therapy for hematological malignancies lies in the successful separation of mature donor T cells that are host-reactive and induce graft-versus-host disease (GVHD) from those that are tumor-reactive and mediate graft-versus-leukemia (GVL) effects. To study whether this separation was possible in an MHC-matched murine BMT model (B10.BR→CBA) with a CBA-derived myeloid leukemia line, MMC6, we used TCR Vβ CDR3-size spectratype analysis to first show that the Vβ13 family was highly skewed in the B10.BR anti-MMC6 CD8+ T cell response but not in the alloresponse against recipient cells alone. Transplantation of CD8+Vβ13+ T cells at the dose equivalent of their constituency in 1×107 CD8+ T cells, a dose that had been shown to mediate lethal GVHD in recipient mice, induced a slight GVL response with no concomitant GVHD. Increasing doses of CD8+Vβ13+ T cells led to more significant GVL responses, but also increased GVHD symptoms and associated mortality. Subsequent spectratype analysis of GVHD target tissues revealed involvement of gut-infiltrating CD8+Vβ13+ T cells accounting for the observed in vivo effects. When BMT recipients were given MMC6 presensitized CD8+Vβ13+ T cells, they displayed a significant GVL response with minimal GVHD. Spectratype analysis of tumor-presensitized, gut-infiltrating CD8+Vβ13+ T cells showed preferential usage of tumor-reactive CDR3-size lengths, and these cells expressed increased effector memory phenotype (CD44+CD62L-/lo). Thus, Vβ spectratyping can identify T cells involved in anti-host and anti-tumor reactivity and tumor-presensitization can aid in the separation of GVHD and GVL responses.

Inhibition of the Immunoproteasome Subunit LMP7 with ONX 0914 Ameliorates Graft-versus-Host Disease in an MHC-Matched Minor Histocompatibility Antigen–Disparate Murine Model

“…In region D the decrease was of 26.16%, whereas the entire MFI shifted 41.93%. CD8 þ T cells [22], we studied specifically the response of CD8 þ B10.BR T cells in MLCs against ONX 0914 or PR-825etreated CBA splenocytes and confirmed that only LMP7-specific inhibition led to a decreased production of IFN-g by this population (Figure 4). …”

“…Although to the best of our knowledge there has been no study demonstrating the LMP7-dependency of the OVA257e264 epitope, we decided to use splenocytes from transgenic B6-SIINFEKL mice because this peptide is known to generate CD8 þ T responsesdthe population largely responsible for GVHD in the B10.BR/ CBA model [22]. Interestingly, we found that the percentage decrease of SIINFEKL expression peaked at 24 hours after a 1-hour exposure to ONX 0914 and that this decrease was less prominent by 48 hours (Figure 7).…”

Strategies for the Identification of T Cell–Recognized Tumor Antigens in Hematological Malignancies for Improved Graft-versus-Tumor Responses after Allogeneic Blood and Marrow Transplantation

“…The adoptive transfer of miHA-specific CTLs selected on the basis of recognition of recipient hematopoietic cells but not skin fibroblasts has also unexpectedly been associated with GVHD. Likewise, in a murine model of BMT, infusion of tumor-specific CTLs identified by CDR3-size spectratype analysis was shown to induce a significant GVT response, but the same tumor-reactive Vβ family, which initially showed no hematopoietic alloreactivity was ultimately the causal entity of gut pathology in recipient mice, when administered at higher dosages [68]. Taken together, the results from these clinical trials and murine models suggest that responses to target tissue–related miHA are complex and may vary not only amongst different individuals but also between tissue types.…”

Establishment of a Murine Graft-versus-Myeloma Model Using Allogeneic Stem Cell Transplantation

“…The Vβ13 family was shown to be highly skewed in the B10.BR CD8 T-cell response against a myeloid leukemia cell line (MMC6), but not in the alloresponse against CBA recipient mice. Transplantation of low doses of CD8 + Vβ13 + T cells, isolated by magnetic cell separation, induced a slight GvT response with no concomitant acute GvHD development [24]. In the B6→Balb.b (MHC-matched) GvHD response, several Vβ families have been found to be skewed within CD4 T cells.…”