-
Assaf Lask,
Eran Ophir,
Noga Or-Geva,
Adva Cohen-Fredarow,
Ran Afik,
Yaki Eidelstein,
Shlomit Reich-Zeliger,
Bar Nathansohn,
Matthias Edinger,
Robert Negrin,
David Hagin,
Yair Reisner
[show abstract]
[hide abstract]
ABSTRACT: Generation of T cells endowed with graft-versus-leukemia (GVL) and depleted of graft versus host (GVH) activity represents a highly desirable goal in bone marrow transplantation (BMT). Here we demonstrate that donor anti 3rd-party CD8 T cells with central memory phenotype (Tcm) exhibit marked GVL reactivity through a unique TCR independent mechanism. Thus, in a residual disease mouse model, Tcm therapy following autologous BMT led to significant survival prolongation, with 30-40% of the treated mice displaying long-term tumor-free survival. More impressive, infusion of donor Tcm in an allogeneic model rapidly eliminated residual lymphoma cells and led to long-term survival of 100%, in the absence of GVHD. Collectively, the strong GVL reactivity of anti 3rd-party Tcm, coupled with their demonstrated enhancement of BM allografting, suggest that the use of Tcm therapy in conjunction with allogeneic T cell depleted BMT could be of particular benefit in patients with B cell malignancies who cannot tolerate intensive myeloablative conditioning.
Blood 02/2013; · 9.90 Impact Factor
-
Eran Ophir,
Noga Or-Geva,
Irina Gurevich,
Orna Tal,
Yaki Eidelstein,
Elias Shezen,
Raanan Margalit, Assaf Lask,
Guy Shakhar,
David Hagin,
Esther Bachar-Lustig,
Shlomit Reich-Zeliger,
Andreas Beilhack,
Robert Negrin,
Yair Reisner
[show abstract]
[hide abstract]
ABSTRACT: Transplantation of T-cell-depleted BM (TDBM) under mild conditioning, associated with minimal toxicity and reduced risk of GVHD, offers an attractive therapeutic option for patients with non-malignant hematologic-disorders and can mediate immune tolerance to subsequent organ transplantation. However, overcoming TDBM rejection following reduced-conditioning remains a challenge. Here, we address this barrier using donor-derived central-memory CD8+T-cells (Tcm), directed against 3rd-party antigens. Our results show that fully allogeneic or (hostXdonor)F1-Tcm, support donor chimerism (>6 months) in sublethaly irradiated(5.5Gy) mice, without GVHD symptoms. Chimerism under yet lower irradiation(4.5Gy) was achieved by combining Tcm with short-term administration of low-dose Rapamycin. Importantly, this chimerism resulted in successful donor skin acceptance, while third-party skin was rejected. Tracking of host-anti-donor T-cells (HADTC), that mediate TDBMT rejection, in a novel bioluminescence-imaging model revealed that Tcm both induce accumulation and eradicate HADTC in the LNs, concomitant with their elimination from other organs, including the BM. Further analysis with 2-photon microcopy revealed that Tcm form conjugates with HADTC, resulting in decelerated and confined movement of HADTC within the LNs in an antigen-specific manner. Thus, anti-3rd-party Tcm support TDBMT engraftment under reduced-conditioning through lymph-node sequestration and deletion of HADTC, offering a novel and potentially safe approach for attaining stable hematopoietic chimerism.
Blood 12/2012; · 9.90 Impact Factor
-
Lior Zangi,
Yael Zlotnikov Klionsky,
Liran Yarimi,
Esther Bachar-Lustig,
Yaki Eidelstein,
Elias Shezen,
David Hagin,
Yumi Ito,
Toshiyuki Takai,
Shlomit Reich-Zeliger, Assaf Lask,
Oren Milstein,
Steffen Jung,
Vera Shinder,
Yair Reisner
[show abstract]
[hide abstract]
ABSTRACT: Immature dendritic cells (imDCs) can have a tolerizing effect under normal conditions or after transplantation. However, because of the significant heterogeneity of this cell population, it is extremely difficult to study the mechanisms that mediate the tolerance induced or to harness the application of imDCs for clinical use. In the present study, we describe the generation of a highly defined population of imDCs from hematopoietic progenitors and the direct visualization of the fate of TCR-transgenic alloreactive CD4(+) and CD8(+) T cells after encountering cognate or noncognate imDCs. Whereas CD4(+) T cells were deleted via an MHC-independent mechanism through the NO system, CD8(+) T-cell deletion was found to occur through a unique MHC-dependent, perforin-based killing mechanism involving activation of TLR7 and signaling through Triggering Receptor-1 Expressed on Myeloid cells (TREM-1). This novel subpopulation of perforin-expressing imDCs was also detected in various lymphoid tissues in normal animals and its frequency was markedly enhanced after GM-CSF administration.
Blood 07/2012; 120(8):1647-57. · 9.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Haploidentical hematopoietic stem cell transplantation (HSCT) offers the advantage of readily available family member donors for nearly all patients. A 'megadose' of purified CD34+ hematopoietic stem cells is used to overcome the host's residual immunity surviving the myeloablative conditioning, while avoiding severe GVHD. However, the number of CD34+ cells that can be harvested is insufficient for overcoming the large numbers of host T cells remaining after reduced intensity conditioning (RIC). Therefore, combining a 'megadose' of CD34+ HSCT with other tolerizing cells could potentially support and promote successful engraftment of haploidentical purified stem cell transplantation under a safer RIC. One approach to address this challenge could be afforded by using Donor CD8 T cells directed against 3rd-party stimulators, bearing an ex-vivo induced central memory phenotype (Tcm). These Tcm cells,depleted of GVH reactivity, were shown to be highly efficient in overcoming host T cells mediated rejection and in promoting fully mismatched bone-marrow (BM) engraftment, in HSCT murine models. This is likely due to the marked lymph node homing of the Tcm, their strong proliferative capacity and prolonged persistence in BM transplant recipients. Thus, combining anti 3rd-party Tcm cell therapy with a 'megadose' of purified CD34+ stem cells, could offer a safer RIC protocol for attaining hematopoietic chimerism in patients with hematological diseases and as a platform for organ transplantation or cell therapy in cancer patients.
Best practice & research. Clinical haematology 09/2011; 24(3):393-401. · 3.13 Impact Factor
-
Assaf Lask,
Polina Goichberg,
Adva Cohen,
Rinat Goren-Arbel,
Oren Milstein,
Shraga Aviner,
Ilan Feine,
Eran Ophir,
Shlomit Reich-Zeliger,
David Hagin,
Tirza Klein,
Arnon Nagler,
Alain Berrebi,
Yair Reisner
[show abstract]
[hide abstract]
ABSTRACT: We previously demonstrated that anti-third-party CTLs (stimulated under IL-2 deprivation against cells with an MHC class I [MHC-I] background different from that of the host and the donor) are depleted of graft-versus-host reactivity and can eradicate B cell chronic lymphocytic leukemia cells in vitro or in an HU/SCID mouse model. We demonstrated in the current study that human allogeneic or autologous anti-third-party CTLs can also efficiently eradicate primary non-Hodgkin B cell lymphoma by inducing slow apoptosis of the pathological cells. Using MHC-I mutant cell line as target cells, which are unrecognizable by the CTL TCR, we demonstrated directly that this killing is TCR independent. Strikingly, this unique TCR-independent killing is induced through lymphoma MHC-I engagement. We further showed that this killing mechanism begins with durable conjugate formation between the CTLs and the tumor cells, through rapid binding of tumor ICAM-1 to the CTL LFA-1 molecule. This conjugation is followed by a slower second step of MHC-I-dependent apoptosis, requiring the binding of the MHC-I α2/3 C region on tumor cells to the CTL CD8 molecule for killing to ensue. By comparing CTL-mediated killing of Daudi lymphoma cells (lacking surface MHC-I expression) to Daudi cells with reconstituted surface MHC-I, we demonstrated directly for the first time to our knowledge, in vitro and in vivo, a novel role for MHC-I in the induction of lymphoma cell apoptosis by CTLs. Additionally, by using different knockout and transgenic strains, we further showed that mouse anti-third-party CTLs also kill lymphoma cells using similar unique TCR-independence mechanism as human CTLs, while sparing normal naive B cells.
The Journal of Immunology 08/2011; 187(4):2006-14. · 5.79 Impact Factor
-
Oren Milstein,
David Hagin, Assaf Lask,
Shlomit Reich-Zeliger,
Elias Shezen,
Eran Ophir,
Yaki Eidelstein,
Ran Afik,
Yaron E Antebi,
Michael L Dustin,
Yair Reisner
[show abstract]
[hide abstract]
ABSTRACT: Cytotoxic T lymphocytes (CTLs) suppress T cell responses directed against their antigens regardless of their own T cell receptor (TCR) specificity. This makes the use of CTLs promising for tolerance induction in autoimmunity and transplantation. It has been established that binding of the CTL CD8 molecule to the major histocompatibility complex (MHC) class I α3 domain of the recognizing T cell must be permitted for death of the latter cell to ensue. However, the signaling events triggered in the CTL by this molecular interaction in the absence of TCR recognition have never been clarified. Here we use single-cell imaging to study the events occurring in CTLs serving as targets for recognition by specific T cells. We demonstrate that CTLs actively respond to recognition by polarizing their cytotoxic granules to the contact area, releasing their lethal cargo, and vigorously proliferating. Using CTLs from perforin knockout (KO) mice and lymphocyte specific kinase (Lck) knockdown with specific small interfering RNA (siRNA), we show that the killing of the recognizing CD8 T cell is perforin dependent and is initiated by Lck signaling in the CTL. Collectively, these data suggest a novel mechanism in which the entire cascade generally triggered by TCR engagement is "hijacked" in CTLs serving as targets for T cell recognition without TCR ligation.
Blood 11/2010; 117(3):1042-52. · 9.90 Impact Factor
