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Although bortezomib and rituximab have synergistic activity in patients with lymphoma and both can attenuate graft-versus-host disease (GVHD), the drugs have not been used together in patients undergoing allogeneic stem cell transplantation (alloSCT). In this phase I/II trial, we assessed the safety and activity of bortezomib added to the rituximab (R) plus BEAM (carmustine, etoposide, cytarabine, melphalan) regimen in patients with relapsed lymphoma undergoing alloSCT. Primary GVHD prophylaxis consisted of tacrolimus and methotrexate. Bortezomib (1 to 1.3 mg/m 2 per dose) was administered i.v. on days -13, -6, -1, and +2. We performed inverse probability weighting analysis to compare GVHD and survival results with an historical control group that received R-BEAM without bortezomib. Thirty-nine patients were assessable for toxic effects and response. The median age was 54 years. The most common diagnosis was diffuse large B cell lymphoma (41%). Twenty-two patients (56%) and 17 patients (44%) received their transplants from matched related and matched unrelated donors, respectively. The maximum tolerated bortezomib dose was 1 mg/m 2 . The weighted cumulative incidences of grades II to IV and III or IV acute GVHD were 50% and 34%, respectively; these incidences and survival rates were not significantly different from those of the control group. Median survival was not reached in patients age ≤ 50 years and with a long follow-up time of 60.7 months. The R-BEAM regimen has a survival benefit in lymphoma patients age ≤ 50 years undergoing alloSCT. The addition of bortezomib has no impact on survival or incidence of GVHD., (Copyright © 2019 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation is mediated by the activation of recipient dendritic cells and subsequent proliferation of donor T cells. The complement system was recently shown to modulate adaptive immunity through an interaction of the complement system and lymphocytes. Complement proteins participate in the activation of dendritic cells, antigen presentation to T cells, and proliferation of T cells. Our studies with a murine model of bone marrow transplantation demonstrate that complement system regulates alloimmune responses in GVHD. Mice deficient in the central component of the complement system (C3(-/-)) had significantly lower GVHD-related mortality and morbidity compared with wild-type recipient mice. The numbers of donor-derived T cells, including IFN-γ(+), IL-17(+), and IL-17(+)IFN-γ(+) subsets, were decreased in secondary lymphoid organs of C3(-/-) recipients. Furthermore, the number of recipient CD8α(+)CD11c(+) cells in lymphoid organs was reduced. We conclude that C3 regulates Th1/17 differentiation in bone marrow transplantation, and define a novel function of the complement system in GVHD., (Copyright © 2012 American Society for Blood and Marrow Transplantation. All rights reserved.)

Allogeneic bone marrow transplantation (BMT) is an effective therapy for hematologic malignancies. However graft-versus-host disease (GVHD) is a major limiting factor for a successful patient outcome. GVHD is a result of alloimmune responses of donor T lymphocytes attacking the recipient's cells and tissues. Chemokine receptor CCR5 plays a role in solid organ allograft rejection and mediates murine GVHD pathogenesis. Herein, we report that infiltrating lymphocytes in the skin of human acute GVHD (aGVHD) samples are predominantly CCR5(+) T cells. In addition, we characterized the features of the CCR5 expression on alloreactive T lymphocytes. We found that the CCR5(+) population exhibits the characteristics of the activated effector T cell phenotype. CCR5 expression is upregulated upon allogenic stimulation, and CCR5(+) cells are proliferating with coexpression of T cell activation markers. Furthermore, the activated T cells producing inflammatory cytokine tumor necrosis factor (TNF)alpha, interleukin (IL)-2, or interferon (IFN)-gamma, are positive for CCR5. Thus, CCR5 is a marker for GVHD effector cells and CCR5(+) T cells are active participants in the pathogenesis of human aGVHD., (Copyright (c) 2010 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Graft-versus-host disease (GVHD) following bone marrow transplantation (BMT) is mediated by alloreactive donor T lymphocytes. Migration and activation of donor-derived T lymphocytes play critical roles in the development of GVHD. Leukocyte function-associated antigen-1 (LFA-1) regulates T cell adhesion and activation. We previously demonstrated that the I-domain, the ligand-binding site of LFA-1, changes from the low-affinity state to the high-affinity state on LFA-1 activation. Therapeutic antagonists, such as statins, inhibit LFA-1 activation and immune responses by modulating the affinity state of the LFA-1 I-domain. In the present study, we report that lovastatin blocked mouse T cell adhesion, proliferation, and cytokine production in vitro. Furthermore, blocking LFA-1 in the low-affinity state with lovastatin reduced the mortality and morbidity associated with GVHD in a murine BMT model. Specifically, lovastatin prevented T lymphocytes from homing to lymph nodes and Peyer's patches during the GVHD initiation phase and after donor lymphocyte infusion (DLI) after the establishment of GVHD. In addition, treatment with lovastatin impaired donor-derived T cell proliferation in vivo. Taken together, these results indicate the important role of lovastatin in the treatment of GVHD.

Myeloid forms of leukemia would seem to be an ideal disease for investigators wishing to develop targeted immunotherapy because the leukemia is derived from antigen-presenting cells and because clinical data have demonstrated that there is potent T-cell immunity to chronic myeloid leukemia when donor lymphocyte infusions are used to treat relapse after transplantation. However, clinical vaccine studies have had to wait for the identification of specific antigens, some of which have recently been identified, and for a more complete understanding of basic tumor immunology. Here we review relevant fundamental T-cell biology, the nature of some important leukemia-associated antigens, and the preliminary results from recent clinical vaccine trials for leukemia. Although these studies are still early, they offer evidence that effective immunity to leukemia is possible after vaccination, thus setting the stage for future combined therapies.