Epigenetic Control of GvHD and Gvl Using the Hypomethylating Agent Azacitidine.

Abstract Abstract 2447 Poster Board II-424 Allogeneic bone marrow transplantation (BMT) represents the most effective treatment for patients with high risk and relapsed hematologic malignancies. One of the major complications of allogeneic BMT is graft-versus-host disease (GvHD), which is caused by donor T cells reacting against host antigens. These same alloreactive donor T cells can provide a beneficial ¡°graft-versus-leukemia¡± (GvL) effect as well resulting in reduction in leukemia relapse. Because regulatory T cells (Tregs) have been shown to suppress GvHD while preserving GvL, their use in the allogeneic transplant setting provides a promising strategy to treat GvHD. However, three major obstacles prevent their routine use in human clinical trials: 1) the low circulating numbers of Tregs in peripheral blood, 2) loss of suppressor activity following ex vivo expansion and 3) the lack of Treg-specific markers to purify ex vivo expanded Tregs. Foxp3 is a forkhead transcription factor which is both exclusively expressed in Tregs and, when overexpressed in conventional effector T cells (Teff), can convert these Teff into functionally suppressive Treg-like T cells. The Foxp3 locus is unmethylated in Tregs while highly methylated and silenced in all other T cells. Several groups have shown that the hypomethylating agent azacitidine (AzaC) induces FOXP3 expression in non-Tregs. Furthermore, we have shown that treatment of anti-CD3/CD28 antibody-coated bead-activated CD4+CD25- T cells with AzaC results in robust and prolonged (>7 days) expression of FOXP3. AzaC-induced FOXP3 expression is also associated with a potent Treg-like suppressive phenotype in vitro. Thus, we hypothesize that AzaC treatment of mice after allogeneic BMT will dramatically mitigate GvHD while preserving GvL via transcriptional regulation of Foxp3 in alloreactive Tconv. In murine T-cell depleted BMT model (B6¡æBalb/c; 900 cGy TBI) with delayed infusion of conventional T cells (Tconv) (2 ×106) at day 11 post BMT, followed by subcutaneous treatment of AzaC (2 mg/kg at days 15, 17, 19, and 21 post BMT), we found that AzaC dramatically suppressed GvHD caused by allogeneic donor T cells while maintaining donor (H2Kb) engraftment of all lineages. We found that the AzaC group had significantly higher FOXP3+ Tregs than in PBS control group and that these Tregs were derived from donor T cells, suggesting that the suppression of GvHD was mediated by AzaC-induced Tregs. We further tested whether AzaC treatment of mice transplanted with allogeneic T cells preserve GvL while mitigating GvHD. Using the same murine allogeneic BMT model, Click Beetle Red luciferase-expressing A20 leukemia cells (BALB/C derived) were injected with T-cell depleted BM and 10 × 106 Tconv and in vivo bioluminescence imaging was performed to assess tumor burden in vivo post transplant. We found that AzaC treatment mitigated GvHD without abrogating GvL (Fig. 1) or donor engraftment. Thus, the adminstration of hypomethlating agents like AzaC in vivo after allogeneic stem cell transplant dramatically reduces GvHD while maintaining both donor engraftment and a potent GvL effect providing the foundations for future clinical trials. Disclosures: DiPersio: Genzyme Corporation: Honoraria.

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Lack of Host Bone Marrow-Derived Interleukin-12 Increased the Incidence of Allograft Rejection in Allogeneic Bone Marrow Transplantation

Blood ◽

10.1182/blood.v118.21.2960.2960 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2960-2960

Author(s):

Ying Wang ◽

Jian-Ming Li ◽

Wayne A.C. Harris ◽

Cynthia R. Giver ◽

Edmund K Waller

Keyword(s):

Bone Marrow ◽

T Cells ◽

T Cell ◽

Allogeneic Bone Marrow Transplantation ◽

Interleukin 12 ◽

Allogeneic Bone ◽

Radiation Chimeras ◽

Allogeneic Bmt ◽

Donor T Cells

Abstract Abstract 2960 Background: Donor cell engraftment following allogeneic bone marrow transplantation (BMT) is affected by several factors, including immunological major histocompatibility complex (MHC) barriers, the intensity of the conditioning regimen, and the content of T-cells in the graft. The current model for engraftment in allogeneic BMT is that host dendritic cells (DCs) activate donor T-cells which promote engraftment by eliminating radio-resistant cytotoxic host immune cells, especially natural killer (NK) cells and T-cells. To explore the interaction between donor T-cell and host antigen-presenting cells (APC) in engraftment in allogeneic BMT, we focused on the role of interleukin-12 (IL-12), a key cytokine produced mainly by DCs that drives the development of donor type 1 helper T cells (Th1) and type 1 cytotoxic T lymphocytes (Tc1). Methods: Radiation chimeras with >95% donor chimerism were created by transplanting 5 × 106 bone marrow (BM) cells from IL-12 knock out (IL-12 KO) or wild type (WT) B6 (H-2Kb, CD45.2) donors into congenic BL6 Pepboy (B6.SJL-PtprcaPep3b/BoyJ, H-2Kb, CD45.1) mice following lethal 11 Gy irradiation. A second allogeneic BMT was conducted 2 months later using MHC mismatched FVB (H-2q, CD45.1), BA.B10 (H-2Kk, CD45.2, CD90.1) or B10.BR (H-2Kk, CD45.2, CD90.2) donor cells. In vivo bioluminescent imaging (BLI) was performed to analyze the number and in vivo distribution of luciferase+ donor T-cells. The whole-body bioluminescent signal was used as a marker of the donor T cell expansion. Engraftment of donor myeloid cells was determined by flow cytometry using mAbs for specific leukocyte markers expressed on donors and recipients (CD45.1, CD45.2, H-2Kb). Intracellular cytokine expression (IL-4, IL-10, IFN-g) by donor CD4+ and CD8+ T cells was analyzed by flow cytometry. Results: WT BL6→BL6 radiation chimeras recipients showed greater expansion of luciferase+ donor T-cells compared with IL-12 KO BL6→BL6 radiation chimeras recipients and FVB→FVB syngeneic recipients at early time point (2 wks) following 9 Gy re-irradiation and transplantation of 3 × 105 luciferase+ FVB-L2G85 T-cells in combination with 5 × 106 T cell depleted (TCD) BM cells from FVB mice following (Fig 1). At 4 weeks post transplant, more WT BL6→BL6 radiation chimeras achieved myeloid engraftment than IL-12 KO BL6→BL6 radiation chimera recipients(75.0% versus 33.3% respectively, p = 0.086), and the former group had better erythroid engraftment than the latter group (RBC 8.65 ± 1.88 × 1012/L versus 5.67 ± 2.22 × 1012/L respectively, p = 0.011). However, when FVB, WT BL6→BL6 or IL-12 KO BL6→BL6 radiation chimeras recipients were conditioned with a larger dose of irradiation prior to the second transplantation (10 Gy) and received a larger dose of donor T-cells (5 × 105), both the WT BL6→BL6 and IL-12 KO BL6→BL6 radiation chimeras recipients achieved full donor engraftments (85.7% versus 87.5% respectively, p = NS). Donor T cells in allogeneic BMT recipients were Th1/Tc1 polarized, there were no differences in frequencies and total numbers of Th1/Tc1 donor CD4+ and CD8+ T cells comparing recipients of WT BL6→BL6 and IL-12 KO BL6→BL6 radiation chimeras. In spite of an increased irradiation dose and larger number of donor T-cells in the second transplant regimen, no increase in graft versus host disease (GVHD) clinical scores and GVHD-mortality were observed in the recipients of WT BL6→BL6 radiation chimeras compared with recipients of IL-12 KO BL6→BL6 radiation chimeras. Conclusion: These data support a role for host BM-derived IL-12 in facilitating engraftment in allogeneic BMT following a reduced dose (9 Gy) radiation. The lack of host BM-derived IL-12 expression led to allograft rejection. Rejection could be overcome by increasing the dose of pre-transplant irradiation and the content of donor T-cells without causing lethal GVHD. As the main source of host BM-derived IL-12, recipient APC thus play an important role in donor T-cell activation. As has been previously demonstrated in a murine BMT model, the addition of IL-12 in the peri-transplant period helped to separate graft versus leukemia effects from the GVHD-promoting activity of donor T-cells (Yang, 1997). Patients predicted to be high risk of graft failure may benefit from treatment strategies that contribute to production of IL-12 during the early phases of hematopoietic engraftment. Disclosures: No relevant conflicts of interest to declare.

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Allograft T Cell Content Influences Early Engraftment after Reduced-Intensity Stem Cell Transplantation (RIST).

Blood ◽

10.1182/blood.v106.11.3662.3662 ◽

2005 ◽

Vol 106 (11) ◽

pp. 3662-3662

Author(s):

Robert M. Dean ◽

Daniel H. Fowler ◽

Nancy M. Hardy ◽

Jeanne Odom ◽

Kathleen Castro ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Ex Vivo ◽

Group Iii ◽

Donor Chimerism ◽

Group I ◽

Gvhd Prophylaxis ◽

Donor T Cells ◽

Reduced Intensity

Abstract Allogeneic hematopoietic stem cells (HSC) generally engraft rapidly and completely after myeloablative conditioning. However, with reduced-intensity conditioning (RIC), mixed chimerism and graft failure are more common. Host immune status and HSC number are factors known to affect engraftment after reduced-intensity stem cell transplantation (RIST). In addition, donor T cells within the allograft may also influencethe kinetics of donor engraftment after RIST. To evaluate this, we performed a controlled comparison of engraftment outcomes among 3 groups undergoing RIST, varying by ex vivo T cell depletion (TCD) or in vivo depletion of activated T cells with methotrexate (MTX) to prevent graft-versus-host disease (GVHD). Group I (n = 50) received T cell replete (TCR) peripheral blood stem cells (PBSC) with cyclosporine (CSA) alone for GVHD prophylaxis. Group II (n = 17) received ex vivo TCD PBSC (positive/negative selection with T cell add-back to uniform dose of 1 x 105 CD3+ cells/kg) with CSA alone for GVHD prophylaxis. Group III (n = 31) received TCR PBSC with CSA plus MTX (5 mg/m2 IV x 4 doses) for GVHD prophylaxis. The 3 groups were similarly immunosuppressed from prior therapy before RIST (median absolute lymphocyte counts 330/μL, 260/μL, and 307/μL for Groups I, II, and III, respectively), and received an identical RIC regimen (fludarabine/cyclophosphamide) plus comparable numbers of filgrastim-mobilized PBSC from HLA-matched sibling donors (median 7.9 x 106, 7.6 x 106, and 6.8 x 106 CD34+ cells/kg, respectively; median 3.6 x 108, 1.0 x 105, and 3.2 x 108 CD3+ cells/kg, respectively). Hematopoietic recovery was slowest in Group III, consistent with the myelosuppressive effects of MTX (Table). A greater proportion of patients in Group I achieved complete donor chimerism (≥ 95%) by day +28 than in Groups II or III (P < 0.025), and at day +100, mixed donor chimerism persisted more often in Groups II and III than in Group I patients (P < 0.01). Correspondingly, early (< day +42) occurrence of grade 3–4 acute GVHD, before initiation of planned sequential donor lymphocyte infusions (DLI) in Group II, was more frequent in Group I than in either Groups II or III (p=0.08). Table: Hematopoietic Recovery, Engraftment, and GVHD Group Days to ANC > 500, median (range) Days to plt > 100, median (range) Donor chimerism ≥ 95% Early acute GVHD, grades 3–4 Day +28 Day +100 I 9 (7–13) 15.5 (12-42) 37/44 (84%) 36/38 (95%) 9/50 (18%) II 9 (7–10) 17.5 (11–40) 8/17 (47%) 9/14 (65%) 0/17 (0%) III 14 (7–21) 21.5 (12–85) 23/31 (74%) 21/31 (68%) 2/31 (6%) Thus, the deletion of T cells by either ex vivo TCD or in vivo MTX administration measurably alters the kinetics and degree of donor T cell engraftment after RIST. These observations provide evidence that donor T cells are an independent factor affecting engraftment of allogeneic HSC after RIST by compensating for incomplete host immune ablation. These data also support the hypothesis that a graft-versus-host effect plays a significant role in engraftment after RIST. Manipulation of donor T cells through graft engineering techniques may be a useful strategy to enhance engraftment in the setting of RIST.

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Use of Ex Vivo Graft Manipulation and Posttransplant Cyclophosphamide Result in Low GvHD Rates and Acceptable Engraftment after RIC Regimens in Pediatric Mismatched SCT

Blood ◽

10.1182/blood-2019-129654 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 3255-3255

Author(s):

Peter Lang ◽

Michaela Döring ◽

Anne-Marie Lang ◽

Patrick Schlegel ◽

Christian M. Seitz ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Immune Suppression ◽

Pediatric Patients ◽

Ex Vivo ◽

Conditioning Regimen ◽

Post Transplant ◽

Donor T Cells ◽

Organ Dysfunctions

Introduction: There are currently two strategies to prevent Graft-versus-Host Diseases (GvHD) mainly applied in haploidentical transplantation. One is ex-vivo T-cell depletion of TcRa/b T-cells and the other is the T-replete approach, in which the donor T-cells remain in the graft and are tolerized in vivo by post-transplant cyclophosphamide (pCy). The ex-vivo depletion strategy does not require post-transplant immune suppression for GvHD prevention, whereas T-replete transplants require intensive immune suppression. A major obstacle for engraftment is the persistence of patients' T-cells despite intensive and myeloablative condition regimens, thus probably leading to rejection of the graft. We hypothesized that both methods could be combined in a setting of Reduced Conditioning setting (RIC). The ex-vivo T-cell depletion would allow to omit post-transplant immunosuppression and the pCy given at day +3 and +4 could induce in-vivo tolerance of the residual patients' T-cells not eliminated by RIC. Therefore, we applied this strategy in patients who were not eligible based on their poor clinical condition and who were considered to endure only a very reduced conditioning regimen. Results: We report on a cohort of 6 pediatric patients who were not eligible for myeloablative condition regimens due to preexisting organ dysfunctions (lungs, gut or liver) but were in urgent need of an SCT from matched unrelated (n=2) or haploidentical family donors (n=4). Diagnoses were: immune deficiencies (n =4; CARMIL 2, STAT 1, ICF 2, 1 not classified), relapsed metastatic ependymoma, refractory Burkitt´s lymphoma. All patients received a non-myeloablative conditioning regimen (ATG (Thymoglobin) 2mg/kg d-9 to d-7, fludarabine 30mg/m² d-6 to d-2, TBI 4Gy d-1, cyclophosphamide 50mg/kg d+3, d+4; adapted from Aversa, Reisner et al. Blood Adv. 2017). One patient additionally received thiotepa 2x5mg/kg on d-2. The CliniMACS® device was used for TCRab/CD19 depletion of peripheral stem cells; a median number of 14x10E6 CD34+ cells/kg bw with 6.4x10E3/kg bw residual TCRa/b T-cells was infused without any further posttransplant immune suppression. Four patients received a single add back of CD45 RA depleted donor T-cells at d+7. Dosages of 1x10E5/kg, 1x10E6/kg or 5x10E6/kg were administered. Two patients received an additional T-cell depleted stem cell boost after application of pCy Engraftment occurred in 4/6 patients; 2 patients rejected their haploidentical grafts and showed complete autologous reconstitution. Median time to reach ANC>500 was 19 days (range 15-23). Four patients had no signs of GvHD; 1 patient had grade I; the patient who had received the highest dose of CD45RA depleted DLI developed grade III but could be treated successfully. No cGvHD occurred. Immune recovery was rapid. Median numbers of CD3+ T-cells, CD3/CD4+ T-cells, CD19+ B cells and CD56+ NK cells at d30 and d100 were 120/µl, 9/µl, 0/µl, 140/µl and 205/µl, 60/µl, 67/µl and 206/µl, respectively. 3 patients are alive and well with a median follow up of 824 days (43-1100). Last observed donor chimerisms were 95-100%. Causes of death in 3 other patients were: MAS/sepsis (STAT 1 deficiency, d 264) and progression in both patients with malignancies (d282 and d73). The patient with relapsed ependymoma showed a transient tumor regression for 3 months posttransplant whereas the patient with refractory Burkitt´s lymphoma had only a short response for 4 weeks. Conclusions: The combination of TCRa/b depletion and pCy allowed to use a very reduced conditioning regimen which could be administered in pediatric patients even with preexisting significant organ dysfunctions without severe side effects. GvHD could be effectively prevented (except in one patient who received a high number of DLI) together with an acceptable engraftment rate provided by post cy. Thus, this method might offer the possibility to establish a donor-derived hematopoiesis without using pharmacological myeloablation and with minimal toxicity and might be the basis for future strategies to further reduce the conditioning regimen, especially for patients with non-malignant diseases. Disclosures No relevant conflicts of interest to declare.

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Depletion of Alloreactive T Cells after Haploidentical HSCT: Comparison of Outcomes for Ex Vivo Versus In Vivo Treatment Strategies

Blood ◽

10.1182/blood-2018-99-118857 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3474-3474

Author(s):

Steven Devine ◽

Stephan Mielke ◽

Eduardo Olavarria ◽

Bert Tuk ◽

Kees Meewisse ◽

...

Keyword(s):

Clinical Trials ◽

T Cells ◽

Single Dose ◽

T Cell ◽

Ex Vivo ◽

Chronic Gvhd ◽

Weighted Average ◽

Alloreactive T Cells ◽

Relapse Rates

Abstract Background: The use of haploidentical allogeneic hematopoietic stem cell transplantation (haplo-HSCT) has increased owing to therapeutic advances that have mitigated the main barriers such as high incidence of graft-versus-host disease (GVHD) and non-relapse mortality (NRM). This is primarily attributable to the elimination of alloreactive T cells in either the patient or the graft. Such T-cell depletion can be performed in vivo early after T-cell-replete haplo-HSCT using post-transplant cyclophosphamide (PTCy). Alternatively, T-cell-depleted haplo-HSCT can be supplemented with T-lymphocytes that are depleted ex vivo of their alloreactive component in the form of ATIR101 (Kiadis Pharma). Patient exposure to PTCy to eliminate donor alloreactive cells can be performed easily and at low cost but may cause patient toxicity and increase relapse rates, and it requires post-transplant immune suppression. Although ATIR101 requires cell manufacturing and is more expensive, it limits toxicity to the patient, enables haplo-HSCT without the use of immunosuppressants, and may reduce relapse rates. Both strategies are promising, but no attempt has yet been made to compare clinical results in similar patient populations to delineate key features of alloreactive T-cell depletion performed either ex vivo or in vivo. Methods: Data from published retrospective studies (single-site or registry data) were analyzed to assess clinical outcomes of haplo-HSCT plus PTCy. The 1-year outcomes from these studies were compared with results from a pooled analysis of 2 phase II clinical trials of a single dose of ATIR101 (N=37, all patients with AML/MDS/ALL [CR-AIR-007, CR-AIR-008]). Studies in which PTCy was used in patient populations with >50% AML/MDS/ALL were identified (Ciurea 2015, Piemontese 2017, Solomon 2012, Ciurea 2012, Devillier 2015, Di Stasi 2014, Esquirol 2016, Sugita 2015). The 1-year rates of relapse, relapse-related mortality (RRM), NRM, GVHD, and overall survival (OS) for the ATIR101 clinical trials were compared with the weighted average of these outcomes for the identified studies. OS is known to correlate with disease risk index (DRI; Armand 2014); therefore, publications reporting both OS and DRI (McCurdy 2017, Ciurea 2015, Devillier 2015, Sugita 2015) were identified to compare OS. Differences in DRI between PTCy and ATIR101 study populations were adjusted according to the relationship between DRI and OS. Finally, PTCy studies reporting GVHD-free and relapse-free survival (GRFS) were identified (Solh 2016, McCurdy 2017, Santoro 2017). There is a clinically relevant and statistically significant correlation between GRFS and DRI, so 1-year GRFS rates from the 2 studies reporting DRI status (Solh 2016, McCurdy 2017) were also normalized according to the DRI profile in the ATIR101 clinical trials to allow comparison. Results: The weighted average of PTCy (N=571) outcomes in populations with >50% AML/MDS/ALL vs ATIR101 patient outcomes were: 29% vs 8% for relapse; 18% vs 8% for RRM; 22% vs 33% for NRM; 5% vs 5% for acute GVHD grade III/IV; 24% vs 3% for chronic GVHD; and 60% vs 58% for OS. The OS in DRI-adjusted studies for PTCy (N=561) was similar to that in ATIR101 clinical trials (63% vs 58%, respectively). The GRFS-reporting studies included a total of 708 patients (Sohl 2016, N=128; McCurdy 2017, N=372; Santoro 2017, N=208); 1-year GRFS rates for PTCy in these studies were 33% (95% CI: 25-41), 45% (95% CI: 40-50), and 33% (average), respectively. In the 2 studies reporting DRI (N=500), the DRI profile was more favorable than in the ATIR101 studies and the 1-year GRFS rates normalized in line with the ATIR101 studies were reduced to 30% (Sohl 2016) and 40% (McCurdy 2017). In patients intended to receive a single dose of ATIR101 after haplo-HSCT, Kaplan-Meier estimate of 1-year GRFS was 53% (95% CI 39-72) (Table 1). Conclusion: This is not a head-to-head comparison, so data should be interpreted with caution. However, in these cross-study analyses, first insights into a potential advantage of ex vivo (ATIR101) over in vivo (PTCy) depletion of alloreactive T cells is suggested, including but not limited to rates of relapse, chronic GVHD, and GRFS. A large, phase III, randomized control trial is thus underway to assess the relative safety and efficacy of ATIR101 after T-cell-depleted haplo-HSCT versus PTCy after T-cell-replete haplo-HSCT (CR-AIR-009 HATCY; NCT02999854). Disclosures Devine: Kiadis Pharma: Consultancy. Mielke:Kiadis Pharma: Other: Travel grants, Research Funding. Tuk:Kiadis Pharma: Consultancy. Meewisse:Kiadis Pharma: Employment. Sandler:Kiadis Pharma: Employment. Roy:University of Montreal: Patents & Royalties: Author on patent; Kiadis Pharma: Other: Travel support; Hopital Maisonneuve Rosemont: Patents & Royalties: Author on patent.

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Critical and Opposing Effects of T Cell-Derived TNFα and Interferon-γ on IL-17 Induction Assessed in Vitro and in Vivo Following Allogeneic Bone Marrow Transplantation

Blood ◽

10.1182/blood.v112.11.3482.3482 ◽

2008 ◽

Vol 112 (11) ◽

pp. 3482-3482

Author(s):

Minghui Li ◽

Kai Sun ◽

Mark Hubbard ◽

Doug Redelman ◽

Angela Panoskaltsis-Mortari ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

Th17 Cells ◽

Allogeneic Bone Marrow Transplantation ◽

Allogeneic Bone ◽

Allogeneic Bmt

Abstract IL-17-producing CD4 T cells (Th17) are a recently identified T helper subset that plays a role in mediating host defense to extracellular bacteria infections and is involved in the pathogenesis of many autoimmune diseases. In vitro induction of IL-17 in murine CD4+ T cells has been shown to be dependent on the presence of the proinflammatory cytokines TGF-β and IL-6 whereas IFNγ can suppress the development of Th17 cells. In the current study, we examined the roles of TNFα and IFNγ on IL-17 production by purified T cells in vitro and in vivo after allogeneic bone marrow transplantation (BMT). We present findings that expression of TNFα by the T cell itself is necessary for optimal development of Th17 under in vitro polarizing conditions. A novel role for T cell-derived TNFα in Th17 induction was observed when in vitro polarization of Tnf−/−CD4+ T cells resulted in marked reductions in IL-17+CD4+ T cells compared to Tnf+/+CD4+ T cells. In marked contrast, T cell-derived IFNγ markedly inhibited Th17 development as more IL-17+CD4+ T cells were found in Ifnγ−/−CD4+ T cells than in Ifnγ+/+CD4+ T cells, and of particular interest was the dramatic increase in IL-17+CD8+ cells from Ifnγ−/− mice. To determine if T cell-derived TNFα or IFNγ can regulate Th17 development in vivo we examined the differentiation of alloreactive donor T cells following allogeneic BMT. We have found that donor-derived Th17 cells can be found in lymphoid tissues and GVHD-affected organs after allogeneic BMT. However, transfer of Tnf−/− CD4+ T cells after allogeneic BMT resulted in marked reductions in Th17 cells in the spleen (18×103 vs 7×103, P<0.05). In agreement with the in vitro data and in contrast to what was observed with transfer of Tnf−/− CD4+ T cells, transfer of donor Ifnγ−/− T cells resulted in marked increases in not only IL-17+CD4+ but also IL-17+CD8+ T cells infiltrating the liver (7×103 vs 14×103, P<0.05; 4×104 vs 12.5×104, P<0.05). These results suggest that the donor T cell-derived TNFα and IFNγ opposingly regulate IL-17 induction of both CD4+ and CD8+ T cells in vitro and after allogeneic BMT which correlates with GVHD pathology.

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Functional Comparison of Freshly Isolated and Ex-Vivo Expanded CD4+CD25+Foxp3+ Regulatory T Cells in Suppressing Murine Acute GvHD

Blood ◽

10.1182/blood.v112.11.812.812 ◽

2008 ◽

Vol 112 (11) ◽

pp. 812-812 ◽

Cited By ~ 1

Author(s):

Emanuela I Sega ◽

Dennis Leveson-Gower ◽

Vu H. Nguyen ◽

Robert Negrin

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Acute Gvhd ◽

Bone Marrow Cells ◽

Ex Vivo ◽

Allogeneic Bone ◽

Cell Reactivity ◽

Hematopoietic Stem

Abstract Graft versus host disease (GVHD) is a major complication of hematopoietic stem cell transplantation resulting from donor T cell reactivity against host tissue antigens. CD4+CD25+Foxp3+ regulatory T cells (Treg) are known to be important in maintaining self tolerance and preventing autoimmunity. Using murine models of acute GVHD in which allogeneic bone marrow cells are transplanted into lethally irradiated hosts, we and others have shown that donor Treg are able to suppress GVHD induced by donor allogeneic T cells and dramatically improve survival. Treg are rare and suppression of GVHD requires adequate numbers of Treg in relation to the number of conventional T cells (Tcon). To overcome this problem, expansion of Treg has been performed, however there has not been a head to head comparison of the function of expanded vs fresh Treg. Highly purified CD4+CD25+Foxp3+ T cells (>98% purity) were expanded using anti-CD3/anti-CD28 dynabeads and 1000 U/ml IL-2. Under these conditions, after five days Treg expanded up to 13 fold while maintaining high Foxp3 expression levels (85–90%). Longer expansion periods result in more T cell expansion but an overgrowth of Foxp3 negative T cells. In a mixed lymphocyte reaction assay, the ex-vivo expanded Treg efficiently suppressed the proliferation of alloreactive T cells. The expanded Treg were evaluated in an in vivo acute GVHD mouse model in direct comparison with freshly isolated Treg using a novel bioluminescent imaging assay that allowed for assessment of Tcon proliferation in addition to traditional metrics of GVHD severity including weight gain, survival and GVHD score. Initial experiments show that, similar to freshly isolated Treg, the ex-vivo expanded Treg suppress GVHD symptoms and improve survival, although a greater number of expanded Treg were required comparable to freshly isolated Treg. The mean GVHD score for the Tcon alone group was 5.8±1.02. Fresh Treg added at 1:1 ratio decreased the GVHD score to 0.75±0.25 (p=0.0036). Ex-vivo expanded Treg demonstrated a dose-dependent decrease in GVHD score, although four times more expanded Treg were needed to obtain a similar reduction in GVHD score (0.50±0.5, p=0.0036). This observed difference in potency was not due to the ex-vivo expanded Treg being short-lived when infused in mice. Bioluminescence imaging of luciferase positive (luc+) cultured Treg showed the same in vivo persistence as freshly isolated Treg. The ability to expand ex-vivo generated Treg is greater than the difference in potency, making ex-vivo expanded Treg potentially a viable option for treatment of GVHD, however, increased ratios of Treg:Tcon are likely to be required.

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Visualizing Allogeneic Bone Marrow (BM) Graft Rejection.

Blood ◽

10.1182/blood.v104.11.43.43 ◽

2004 ◽

Vol 104 (11) ◽

pp. 43-43

Author(s):

Patricia Taylor ◽

Angela Panoskaltsis-Mortari ◽

Randolph Noelle ◽

Alexander Rudensky ◽

Jonathan Serody ◽

...

Keyword(s):

Bone Marrow ◽

T Cells ◽

T Cell ◽

The Body ◽

Allogeneic Bone Marrow ◽

Therapeutic Interventions ◽

Organ Distribution ◽

Allogeneic Bone ◽

Allogeneic Bmt

Abstract The process by which bone marrow is rejected by host T cells has not been able to be directly visualized to date. To study the process of allogeneic bone marrow rejection and the effects of therapeutic interventions, we created 2 models that allow us to 1) quantify the specific expansion of host-type alloreactive T cells early post-transplant in response to allogeneic BM infusion and to 2) image host T cells in vivo during BM rejection. For the first model, 2C and TEa lymph node (LN) cells were adoptively transferred into syngeneic C57BL/6 (B6) Rag deficient mice on d-2. 2C CD8+ and TEa CD4+ T cell receptor transgenic T cells are reactive against BALB/c alloantigen. Mice were irradiated with 200 cGy on d-1 and BALB/c BM was infused on d0. Controls included mice that received 2C/TEa LN cells but no BM. Ten days later, spleen analysis revealed that 2C CD8+ and TEa CD4+ T cells had expanded 322-fold and 33-fold (ave of 6 exp.), respectively, in mice receiving BALB/c BM compared to controls that did not receive BM. Expanded T cells were activated as determined by flow cytometric parameters and cell surface antigens. Data indicate that host alloreactive T cell expansion was inhibited by >95% by combined, but not single, costimulatory pathway blockade. Studies are in progress to analyze in vitro host anti-donor responses of adoptively transferred T cells. To visualize the response of host T cells to donor BM in vivo, we developed a rejection model for imaging involving the adoptive transfer of green fluorescent protein (GFP) T cells (obtained from GFP transgenic mice) into syngeneic non-GFP B6 recipients immediately following sublethal irradiation (500 cGy). Allogeneic BALB/c or syngeneic B6 BM was infused the following day. The syngeneic BMT controls allowed for the distinction of homeostatic vs alloreactive expansion of GFP+ T cells. Transplanted mice not receiving GFP T cells served as negative controls to verify lack of autofluorescence. Cohorts were imaged d4 to d18 post BMT. By d4, low numbers of GFP+ cells were evident in femoral BM cavity, peripheral and mesenteric LNs, spleen, Peyer’s patches (PP) and to a lesser extent, lung. By d7, massive expansion of GFP+ cells could be visualized throughout the body of recipients of allogeneic BM. LNs, spleen, PP (peri-follicular area) and BM cavity increased dramatically in GFP intensity from d4 to d7. On d7 to d14, there were large foci of GFP+ cells in the lung, liver, skin, gingiva, kidney, uterus, and colon in allogeneic BMT recipients. Compared with allogeneic BMT recipients, syngeneic BMT recipients had greatly reduced numbers of GFP+ T cells in lymphoid organs and only rare cells were noted in liver, kidney, skin, BM and gingiva. In both allogeneic and syngeneic BMT recipients, lengths of ileum were diffusely infiltrated while other sections contained discrete foci of GFP+ cells. These imaging data provide a vivid illustration of the massive expansion and multi-organ distribution of host anti-donor T cells in vivo. Recent generation of GFP+ 2C and GFP+ TEa mice will permit the imaging of alloantigen-specific T cells during a rejection response. Additional imaging experiments are planned to study the fate of GFP+ BM transferred to allogeneic recipients under conditions of engraftment vs rejection. These models provide a unique platform for the testing of therapeutic interventions.

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The Comparison of In Vitro and In Vivo Anti-Host Responses as a Predictor of T Cell Reactivity after Allogeneic-BMT as Determined by TCR Vb Spectratype Analysis.

Blood ◽

10.1182/blood.v108.11.5179.5179 ◽

2006 ◽

Vol 108 (11) ◽

pp. 5179-5179

Author(s):

Thea M. Friedman ◽

Olga Y. Azhipa ◽

Joanne Filicko ◽

Bijoyish Mookerjee ◽

Neal Flomenberg ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

In Vitro Culture ◽

Culture System ◽

Allogeneic Bmt ◽

Donor T Cells ◽

In Vitro Culture System ◽

Leukemic Relapse

Abstract Immunotherapeutic strategies have gained recognition as viable alternatives to more conventional therapeutic modalities for the treatment of cancer. In this regard, adoptive T cell therapy through allogeneic blood and marrow transplantation (BMT) has offered the first evidence to demonstrate that anti-tumor effects could be achieved against hematological malignancies. However, complications which include graft failure, opportunistic infections, leukemic relapse and graft-versus-host disease (GVHD) underscore the importance for the development of more targeted strategies in order to promote the successful implementation of allogeneic-BMT as a long term curative approach. It is well understood that mature donor T cells present in the donor inoculum must be an integral part of any such strategy as they play a pivotal role in all of the above mentioned complications. The incidence of the first three complications is diminished by the presence of mature donor T cells while, unfortunately, the transplantation of mature alloreactive donor T cells also directly induces the latter complication of acute GVHD, which can be directed against either HLA or minor histocompatibility antigen (miHA) disparities. Efforts to pan deplete donor marrow inoculum of T cells have been successful in minimizing the development of disease but have been associated with increased leukemic relapse. Thus, one approach to solve this problem would be to identify and then selectively deplete alloreactive donor T cells while allowing the residual T cells to provide protection against infection and to mediate a leukemia-specific GVL response. We hypothesized that an in vitro culture system using a one-way mixed lymphocyte reaction generated between a potential allogeneic BMT donor and their respective recipient could give rise to many of the alloreactive T cell responses that would be predictive of those that would be generated in vivo, following BMT. We proceeded to test the predictive value of the in vitro culture system through the use of TCR CDR3 Vβ spectratype analysis in the clinical BMT setting. To this end we compared, by spectratype analysis, the in vitro and post-transplant in vivo responses of nine donor patient pairs. The results indicated a high association of overlapping Vβ CDR3-size skewing as defined by the reactive Vβ families in the patient post-transplant also found to be reactive in the in vitro culture system (range of overlap 50–100%, median 72.5%). Thus, in vitro spectratyping analysis may be useful in guiding the manipulation of the donor T cell inoculum in order to provide improved BMT outcomes.

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A Step towards Reconstitution or Maintenance of Remission before or after Stem Cell Transplantation in AML/MDS by Ex Vivo Generation of Leukaemia-Derived DC (DCleu) and DC-Activated T-Cells: Role of the Quality and Quantity of DC/DCleu and Anti-Leukemia-Directed T-Cells To Predict the Course and Success of Immunotherapy.

Blood ◽

10.1182/blood.v108.11.3246.3246 ◽

2006 ◽

Vol 108 (11) ◽

pp. 3246-3246

Author(s):

Helga M. Schmetzer ◽

Anja Liepert ◽

Christine Grabrucker ◽

Andreas Kremser ◽

Julia Loibl ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Ex Vivo ◽

Leukemic Cells ◽

Cytotoxic Lymphocytes ◽

Activated T Cells ◽

Gm Csf ◽

Donor T Cells

Abstract The presentation of leukemic antigens can be improved in AML and MDS by in vitro conversion of leukemic cells in leukemia-derived DC (DCleu), thereby forming a platform for the generation of leukemia-specific cytotoxic lymphocytes (CTL). In preliminary analyses with 140 AML and 60 MDS-cases we could already define optimal serum-free culture conditions to generate DC/DCleu.(Kufner 2005 I–III). Now we want to predict or correlate the clinical response to a DC/CTL-based immunotherapy by detailed analyses of the ex vivo generated/activated DC/DCleu and T-cells: 1)By a combination of 3 different DC-generating methods (‘MCM-mimic’, Lee 2003; ‘Ca-Ionophore’, Houtenbos 2003; ‘Picibanil’, Sato 2003) we can generate DC/DCleu in every case of AML/MDS, independently from FAB-type or karyotype. DC/DCleu are quantified according to their surface DC/blast-marker profiles. On average 42–45%/39–66% DC in AML/MDS could be generated with 48–54%/39–51% mature (CD83+) and 31–34%/23–31% migratory (CCR7+) DC. 45–65% of DC were ‘DCleu’; on average 47% of blasts are convertible to DCleu.. 2) In AML-patients who had presented with a relapse after SCT we could correlate a better ex vivo convertibility of blasts to DCleu with the patients’ in vivo response to a GM-CSF/Donor-lymphocyte Infusion (DLI)-therapy of their relapse after SCT (33% vs 7% to DCleu convertible blasts in ‘non-responders’). 3) A ‘Mixed lymphocyte culture’ (MLC) of autologous AML-patients’ or allogeneic donor-T-cells showed an on average higher proliferation and stimulation of DC-primed compared to MNC-primed T-cells: Upregulation of CD80/CD86-CD28;CD40-CD154;CD137L-CD137; moreover DC-priming yielded higher proportions of CD4+ cells, CD3+CD45RO+ memory cells CCR4+ T-cells (+59%, +52%, +91%) compared to MNC-primed T-cells (+35%, +13%, +44%) and a higher leukaemia-cytolytic activity (average 62%) compared to MNC-stimulated CTL (average 26%). 4) A detailed analysis of data showed great individual variations depending on the quality and composition of DC and T-cells: a) non-DC-primed autologous or allogeneic T-cells an lead to an increase of naive blasts after 3h incubation with blasts b) in cases with an ineffective DC-mediated ex vivo lysis of naïve blasts lower proportions of mature DC (29% vs 63%), DCleu (41% vs 68%) or a reduced T-cell proliferation or even loss of CD4/CD8/memory T-cells were seen. In summary our data show 1. that DC/DCleu can be generated in every single AML/MDS-case. 2. Grade of ex-vivo generability of DC/DCleu correlates with the in vivo response to a GM-CSF/DLI-relapse therapy. 3. Composition and quality of DC and autologous or donor T-cells after DC-priming provides informations about the activability and quality of CTLs in individual patients. We conclude, that ex vivo analysis of the DC/anti-leukemic T-cell-activability is necessary to develop and select promising anti-leukemia-directed T-cells for the immunotherapy of AML and MDS.

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Allogeneic Recipients of Ex-Vivo Manipulated Donor T Cells Have Altered Plasma Analyte Profiles Compared to Recipients of Unmanipulated T Cells.

Blood ◽

10.1182/blood.v108.11.3227.3227 ◽

2006 ◽

Vol 108 (11) ◽

pp. 3227-3227

Author(s):

Michael P. Rettig ◽

Julie K. Ritchey ◽

John F. DiPersio

Keyword(s):

Growth Hormone ◽

T Cells ◽

T Cell ◽

High Efficiency ◽

Ex Vivo ◽

Growth Hormone Secretion ◽

Suicide Gene ◽

Allogeneic Bmt ◽

Donor T Cells ◽

Cell Groups

Abstract Background: Maintaining T cell function and survival after ex vivo manipulation remains a major challenge in adoptive immunotherapy. We previously demonstrated that murine T cells activated and expanded ex-vivo with anti-CD3 and anti-CD28 antibody-coated magnetic beads (CD3/CD28 beads) exhibit reduced GVHD-inducing potential compared to naïve (unmanipulated) T cells in a murine allogeneic BMT model. Blood diagnostics are commonly used to help identify patterns of biomarkers in multiple disease states. Objective: Determine if plasma profiles of 59 different analytes are altered in murine allogeneic BMT recipients who receive ex-vivo activated, suicide gene transduced and selected (Td) T cells compared with animals that received naïve suicide gene expressing T cells. Methods: Murine T cells were Td with a chimeric CD34-thymidine kinase (CD34-TK) fusion suicide gene. High efficiency (70%) gene transfer of CD34-TK to C57BL/6 (B6) murine T cells was accomplished 24 h after CD3/CD28 bead activation and gene-modified cells were purified to > 96% by CD34 immunomagnetic selection 2 days post-infection. Naïve B6 CD34-TK-expressing T cells were purified from the spleens of CD34-TK transgenic mice the day of BMT. To induce GVHD, lethally irradiated BALB/c allogeneic recipients were given T cell depleted (TCD) B6 BM supplemented with or without B6 CD34-TK purified naïve or Td T cells. Animals were bled 1 week after BMT and EDTA plasma samples were prepared and frozen. Quantitative measurements of 59 analytes were obtained using a rodent multi-analyte profile test (MAP test; Charles River Lab) on the plasma of 2 mice that received naïve T cells and died from GVHD on days 16 and 21 after BMT, 2 mice that received Td T cells and died from GVHD on day 34 after BMT, and 2 mice that received TCD BM only and survived > 100 days. Results: As before, we found that ex vivo activation of the donor T cells before BMT significantly prolonged the survival of mice transplanted with the Td T cells compared with mice receiving naïve T cells (p = 0.0028). Eighteen analytes, including IFN-γ, IL-2, IL-3, IL-4, IL-7, IL-11, and TNF-α were below the detection limits of the rodent MAP test for all samples analyzed. Twenty-six analytes, including VEGF, SCF, MIP-2, MIP-1α, MIP-3β, MCP-5, IL-1β, IL-18 and GM-CSF were detectable but not significantly different than the BM only controls for either the naïve or Td T cell groups. Nine analytes, including eotaxin, MIP-1γ, MCP-3, MCP-1, and IL-10 were similarly increased 2- to 3-fold in both the Td and naïve T cell groups compared to the BM only control. Interestingly, recipients of naive T cells exhibited increased plasma levels of growth hormone (≥14-fold), MIP-1β (4.6-fold), IP-10 (2.3-fold), and lymphotactin (2-fold), as well as decreased levels of leptin (≥14-fold), compared to both the BM only and Td T cell groups. This extreme modulation of growth hormone and leptin levels is particularly interesting given the fact that leptin influences local growth hormone secretion from lymphocytes and that both of these analytes have multiple biologic effects on T cells. Finally, only a single analyte, monocyte derived chemokine (MDC), was increased (4-fold) in mice that received Td T cells compared to the naïve T cell recipients. Conclusion: These results indicate that several plasma analytes with important immunological functions are altered when donor T cells are manipulated ex-vivo. These alterations may account for the decreased GVHD-inducing potential of ex vivo manipulated T cells after allogeneic BMT.

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