Suicide gene therapy of graft-versus-host disease induced by central memory human T lymphocytes

Abstract

In allogeneic hematopoietic cell transplantation (allo-HCT), the immune recognition of host antigens by donor T lymphocytes leads to a beneficial graft-versus-leukemia (GvL) effect as well as to life-threatening graft-versus-host disease (GvHD). Genetic modification of T lymphocytes with a retroviral vector (RV) expressing the herpes simplex virus-thymidine kinase (TK) suicide gene confers selective sensitivity to the prodrug ganciclovir (GCV). In patients, the infusion of TK ؉ lymphocytes and the subsequent administration of GCV resulted in a time-wise modulation of antihost reactivity for a GvL effect, while controlling GvHD. Because activation required for genetic modification with RV may reduce antihost reactivity, we investigated the requirements for maximizing the potency of human TK ؉ lymphocytes. Whereas T-cell receptor triggering alone led to effector memory (EM)TK IntroductionAllogeneic hematopoietic cell transplantation (allo-HCT) is the curative option for many hematologic malignancies. Moreover, it is being investigated to treat solid tumors. In allo-HCT, the recognition of host antigens by donor T lymphocytes evokes a graft-versusleukemia (GvL) effect. 1 This is associated with the risk of graft-versus-host disease (GvHD). T-cell depletion prevents GvHD but increases the probability of leukemia relapse. Suicide gene therapy offers a pragmatic solution to the "T-cell dilemma" of allo-HCT. 2 A suicide gene codifies for a protein able to convert, at a cellular level, a nontoxic prodrug into a toxic product. Suicide gene modification of donor lymphocytes aims at exploiting allo-HCT for a GvL effect, while providing a selective "switch" to GvHD. 3 The thymidine kinase of herpes simplex virus (TK) is a cell cycledependent suicide gene, that is, it catalyzes the generation of triphosphate ganciclovir (GCV), which is toxic to proliferating cells. 4 In HLA-identical allo-HCT, delayed infusions of TK ϩ lymphocytes were effective against relapsing leukemia, lymphoma, multiple myeloma, and Epstein-Barr virus (EBV)-related lymphoproliferative disorders. 5 When administered at the time of transplantation, TK ϩ lymphocytes facilitated the engraftment of hematopoietic cells. 6,7 In patients developing GvHD, GCV administration eliminated circulating TK ϩ cells and controlled the disease. [5][6][7] Despite these encouraging results, dissemination of the TK technology has been limited by the difficulty in defining optimal conditions for cell manipulation. Current protocols for genetic modification of T lymphocytes with retroviral vectors (RVs) may reduce antigen responsiveness in vitro 8 and antihost reactivity in vivo. 9,10 Given the strict clinical association between GvL and GvHD, it may be postulated that the therapeutic efficacy of TK ϩ lymphocytes will be improved by protocols designed to maximize antihost reactivity in vivo.Genetic modification of T lymphocytes with RVs relies on cell proliferation and leads to a memory phenotype. 11,12 Different models have been proposed to describe mature T-cell differentia...

Factors affecting human T cell engraftment, trafficking, and associated xenogeneic graft-vs-host disease in NOD/SCID β2mnull mice

“…injection of 12-day CD3/CD28 bead activated huT into anti-CD122 treated and irradiated NOD/SCID recipients (58% lethal X-GVHD for 12-day activated huT versus 100% for non-activated huT). In summary, our findings further illustrate the preservation of huT cell function following CD3/ CD28 bead stimulation and will allow us to evaluate the efficacy of GVHD prevention strategies, such as suicide gene therapy [39], requiring ex vivo T cell activation and expansion.…”

“…Interestingly, although the X-GVHDinducing potential of 4-and 8-day activated huT cells were similar, we found that the engraftment, in-vivo expansion, and tissue infiltration of 8-day activated huT cells was significantly decreased compared to cells that were cultured for only 4 days. This decreased huT cell engraftment and expansion following prolonged ex-vivo activation may explain why Bondaza et al [39] observed decreased lethal X-GVHD following the i.p. injection of 12-day CD3/CD28 bead activated huT into anti-CD122 treated and irradiated NOD/SCID recipients (58% lethal X-GVHD for 12-day activated huT versus 100% for non-activated huT).…”

“…pretransplant conditioning with sublethal irradiation [19,23,26,[32][33][34][35][36][37][38][39][40], (ii.) targeted reduction of murine natural killer (NK) cell activity with antibodies directed towards specific cell membrane markers (anti-asialo-GM1 [19,[33][34][35] or anti-CD122 [23,36,39]), (iii.) targeted reduction of murine macrophages with clodronate-containing liposomes [37], (iv.)…”

A high proportion of donor CD4+ T cells expressing the lymph node-homing chemokine receptor CCR7 increases incidence and severity of acute graft-versus-host disease in patients undergoing allogeneic stem cell transplantation for hematological malignancy

“…15 In humans, it has been shown that CD4 þ CD62L þ T cells responded better to alloantigens than the CD62L neg memory subsets in both proliferation and cytotoxicity assays, 16 and in vitro-generated T CM appeared to be more potent than T EM in an experimental model of GVHD. 17 Thus, the initiation of GVHD seems to depend on the representation of alloreactive cells within naive and/or central memory subsets in the graft, but no clinical study has yet sustained these experimental or in vitro data.…”

Prophylaxis of acute GVHD: manipulate the graft or the environment?

“…Several phase-I/II studies using this technology have been completed and thus provide proof of principle. 15,16 …”