scholarly journals Chimerism of Blood T-Cells and Leukemia Lineage Cells Following Myeloablative Hematopoietic Cell Transplantation Is a Risk Factor for Relapse and Chronic Graft-Versus-Host Disease

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4887-4887
Author(s):  
Rutvij A. Khanolkar ◽  
Poonam Dharmani-Khan ◽  
Faisal M Khan ◽  
Jan Storek
Keyword(s):  
T Cells ◽  
Risk Factor ◽  
T Cell ◽  
Predictive Value ◽  
Hematopoietic Cell ◽  
Mixed Chimerism ◽  
Post Transplant ◽  
Gvhd Prophylaxis ◽  
Sensitivity Specificity ◽  
Subsequent Relapse

Abstract Background: Mixed chimerism of blood leukemia lineage cells has been reported to be highly predictive of relapse (Mattsson J et al. Leukemia 2001), but the utility of T-cell chimerism is controversial. Methods: Chimerism of T-cells (CD3 +) and leukemic lineage cells (CD13 +/CD33 + for myeloid malignancies and CD19 + for B-lymphoid malignancies) was measured in the peripheral blood for 600 hematopoietic cell transplant (HCT) recipients at 3-months post-transplant. Conditioning was myeloablative (fludarabine+busulfan+4GyTBI) and GVHD prophylaxis was with ATG+CsA+MTX. Results: Mixed (<95% donor) chimerism was present in 6% of patients in the leukemic lineage and 16% of patients in T-cells. Compared to patients with complete chimerism (≥95%), mixed chimerism predicted a significantly greater incidence of relapse (52% vs. 27%, P=0.044), and surprisingly, also a greater incidence of cGVHD (43% vs. 23%, P=0.028). Patients with mixed leukemic lineage chimerism also had poorer cGRFS (7% vs. 39%, P<0.001) and OS (29% vs. 55%, P<0.001). Mixed T-cell chimerism predicted a significantly greater incidence of relapse (46% vs. 24%, P<0.001) and lower cGVHD incidence (9% vs. 31%), with no difference in cGRFS or OS. The sensitivity/specificity/positive predictive value (PPV)/negative predictive value (NPV) of mixed leukemic lineage and T-cell chimerism for relapse were 65%/55%/35%/81% and 66%/57%/60%/79%, respectively. Sensitivity/specificity/PPV/NPV was similarly poor for cGVHD. In patients with complete leukemic lineage chimerism at 3-months, a ≥5% drop in donor chimerism at any future timepoint had sensitivity/specificity/PPV/NPV of 82%/79%/79%/82% for subsequent relapse. Conclusion: In the setting of myeloablative conditioning and ATG-based GVHD prophylaxis, mixed chimerism at 3-months post-transplant is a risk factor for subsequent relapse. However, the utility of these measurements in guiding medical interventions may be limited by insufficient predictive values. Nevertheless, patients with mixed chimerism may be candidates for more intensive surveillance. Disclosures Storek: Atara Biotherapeutics: Other: Site PI, Research Funding.

Donor DC Subsets Polarize Donor T-Cell Immune Responses in Allogeneic BMT.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 573-573
Author(s):  
Jian-Ming Li ◽  
Cynthia Giver ◽  
Doug McMillan ◽  
Wayne Harris ◽  
David L. Jaye ◽  
...  
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Peripheral Blood ◽  
Immune Reconstitution ◽  
Hematopoietic Cell ◽  
Post Transplant ◽  
Donor T Cells ◽  
Ifn Γ

Abstract Introduction: Impaired or inappropriate immune reconstitution after allogeneic bone marrow transplantation (BMT) can lead to infection, graft-versus-host disease (GvHD) and leukemia relapse. We have previously reported that BM contains two populations of dendritic cell (DC) subsets, CD11b+ DC and CD11b− DC, and that CD11b depleted donor BM promoted increased donor T-cell chimerism and increased graft-versus-leukemia (GvL) activity in C57BL/6 → B10BR transplants [BBMT, 2004, 10: 540]. To explore the mechanism by which CD11b-depletion improved allo-reactivity, we performed allogeneic hematopoietic cell transplants using defined populations of donor stem cells, DCs, and T-cells in a MHC mis-matched BMT model. Methods: We transplanted FACS purified populations of 50,000 GFP+ CD11b- DC or CD11b+ DC in combination with 5,000 FACS purified Lin- Sca-1+ c-kit+ hematopoietic stem cells (HSC) and 300,000 or 1,000,000 congenic spleen T-cells from C57BL/6 donors into C57BL/6[H-2Kb], B10BR[H-2Kk] and PL/J[H-2Ku] recipients. Proliferation of CFSE stained donor T-cells was measured at 72 hours post-transplant. FACS cytometric bead array and intracellular cytokine staining measured serum and intracellular cytokines in donor T-cells. Results: The initial proliferation and Ki-67 expression of CFSE labeled donor T-cells in allogeneic recipients were much higher than in syngeneic recipients (homeostatic proliferation). Confocal microscopy showed co-localization of donor DC subsets with donor T-cells in the recipient spleens at 3 and 10 days post-transplant. In the allogeneic transplant settings, donor T-cells co-transplanted with CD11b- DC showed increased IFN-γ synthesis at 3 and 10 days post-transplant compared to donor T-cells co-transplanted with HSC plus CD11b+ DC or HSC alone. Increased proliferation of donor T-cells led to increased donor T-cell chimerism at day 10, 30, 60, and day105 post-transplant among recipients of CD11b- DC compared to recipients of HSC alone or HSC plus CD11b+ DC (Figure 1). Transplantation of spleen T-cells and CD11b- DC did not increase GvHD, but was associated with full donor chimerism. In contrast, transplantation of allogeneic CD11b+ DC led to persistence and expansion of residual host T-cells (Figure 2), increased numbers of donor CD4+CD25++Foxp3+ T-cells, and higher serum level of IL-10 supporting early post-transplant expansion of donor T regulatory cells (Treg). Conclusions: Donor CD11b- DC promoted immune reconstitution by polarizing donor T-cells to Th1 immune responses associated with increased IFN-γ synthesis and donor T-cell proliferation, while donor CD11b+ DC suppressed immune reconstitution by inhibiting donor T-cell allogeneic immune responses. These data support a novel paradigm for the regulation of post-transplant immunity and suggest clinical methods to test the hypothesis that manipulation of the DC content of a hematopoietic cell allograft regulates post transplant immunity in the clinical setting. Figure 1. Donor Spleen Derived T-cells in Peripheral Blood [* p<0.05, v.s. recipients of HSC plus CD11b(+)DC and spleen T-cells] Figure 1. Donor Spleen Derived T-cells in Peripheral Blood [* p<0.05, v.s. recipients of HSC plus CD11b(+)DC and spleen T-cells] Figure 2. Host Derived T-cells in Peripheral Blood [* p<0.05, v.s. recipients of HSC plus CD11b(-)DC and spleen T-cells] Figure 2. Host Derived T-cells in Peripheral Blood [* p<0.05, v.s. recipients of HSC plus CD11b(-)DC and spleen T-cells]

Pentostatin Facilitates Fully MHC-Disparate Murine Mini-Transplantation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3539-3539
Author(s):  
Jacopo Mariotti ◽  
Kaitlyn Ryan ◽  
Paul Massey ◽  
Nicole Buxhoeveden ◽  
Jason Foley ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Suppression ◽  
Graft Rejection ◽  
Mixed Chimerism ◽  
Post Transplant

Abstract Abstract 3539 Poster Board III-476 Pentostatin has been utilized clinically in combination with irradiation for host conditioning prior to reduced-intensity allogeneic hematopoietic stem cell transplantation (allo-HSCT); however, murine models utilizing pentostatin to facilitate engraftment across fully MHC-disparate barriers have not been developed. To address this deficit in murine modeling, we first compared the immunosuppressive and immunodepleting effects of pentostatin (P) plus cyclophosphamide (C) to a regimen of fludarabine (F) plus (C) that we previously described. Cohorts of mice (n=5-10) received a three-day regimen consisting of P alone (1 mg/kg/d), F alone (100 mg/kg/d), C alone (50 mg/kg/d), or combination PC or FC. Combination PC or FC were each more effective at depleting and suppressing splenic T cells than either agent alone (depletion was quantified by flow cytometry; suppression was quantified by cytokine secretion after co-stimulation). The PC and FC regimens were similar in terms of yielding only modest myeloid suppression. However, the PC regimen was more potent in terms of depleting host CD4+ T cells (p<0.01) and CD8+ T cells (p<0.01), and suppressing their function (cytokine values are pg/ml/0.5×106 cells/ml; all comparisons p<0.05) with respect to capacity to secrete IFN-g (13±5 vs. 48±12), IL-2 (59±44 vs. 258±32), IL-4 (34±10 vs. 104±12), and IL-10 (15±3 vs. 34±5). Next, we evaluated whether T cells harvested from PC-treated and FC-treated hosts were also differentially immune suppressed in terms of capacity to mediate an alloreactive host-versus-graft rejection response (HVGR) in vivo when transferred to a secondary host. BALB/c hosts were lethally irradiated (1050 cGy; day -2), reconstituted with host-type T cells from PC- or FC-treated recipients (day -1; 0.1 × 106 T cells transferred), and challenged with fully allogeneic transplant (B6 donor bone marrow, 10 × 106 cells; day 0). In vivo HVGR was quantified on day 7 post-BMT by cytokine capture flow cytometry: absolute number of host CD4+ T cells secreting IFN-g in an allospecific manner was ([x 106/spleen]) 0.02 ± 0.008 in recipients of PC-treated T cells and 1.55 ± 0.39 in recipients of FC-treated cells (p<0.001). Similar results were obtained for allospecific host CD8+ T cells (p<0.001). Our second objective was to characterize the host immune barrier for engraftment after PC treatment. BALB/c mice were treated for 3 days with PC and transplanted with TCD B6 bone marrow. Surprisingly, such PC-treated recipients developed alloreactive T cells in vivo and ultimately rejected the graft. Because the PC-treated hosts were heavily immune depleted at the time of transplantation, we reasoned that failure to engraft might be due to host immune T cell reconstitution after PC therapy. In an experiment performed to characterize the duration of PC-induced immune depletion and suppression, we found that although immune depletion was prolonged, immune suppression was relatively transient. To develop a more immune suppressive regimen, we extended the C therapy to 14 days (50 mg/Kg) and provided a longer interval of pentostatin therapy (administered on days 1, 4, 8, and 12). This 14-day PC regimen yielded CD4+ and CD8+ T cell depletion similar to recipients of a lethal dose of TBI, more durable immune depletion, but again failed to achieve durable immune suppression, therefore resulting in HVGR and ultimate graft rejection. Finally, through intensification of C therapy (to 100 mg/Kg for 14 days), we were identified a PC regimen that was both highly immune depleting and achieved prolonged immune suppression, as defined by host inability to recover T cell IFN-g secretion for a full 14-day period after completion of PC therapy. Finally, our third objective was to determine with this optimized PC regimen might permit the engraftment of MHC disparate, TCD murine allografts. Indeed, using a BALB/c-into-B6 model, we found that mixed chimerism was achieved by day 30 and remained relatively stable through day 90 post-transplant (percent donor chimerism at days 30, 60, and 90 post-transplant were 28 ± 8, 23 ± 9, and 21 ± 7 percent, respectively). At day 90, mixed chimerism in myeloid, T, and B cell subsets was observed in the blood, spleen, and bone marrow compartments. Pentostatin therefore synergizes with cyclophosphamide to deplete, suppress, and limit immune reconstitution of host T cells, thereby allowing engraftment of T cell-depleted allografts across MHC barriers. Disclosures: No relevant conflicts of interest to declare.

Influence of Graft Versus-Host Disease Prophylaxis Regimen On T-Cell Repertoire Diversity Following Reduced-Intensity HLA-Matched Unrelated Donor Allogeneic Hematopoietic Stem Cell Transplantation.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3054-3054 ◽  
Author(s):  
Rachel B. Salit ◽  
Frances T. Hakim ◽  
Michael R. Bishop ◽  
Thea M. Friedman ◽  
Robert Korngold ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Reconstitution ◽  
Unrelated Donor ◽  
Matched Unrelated Donor ◽  
Cell Repertoire ◽  
Post Transplant ◽  
Gvhd Prophylaxis ◽  
Repertoire Diversity ◽  
Reduced Intensity

Abstract Abstract 3054 Background: A clearly superior graft-versus-host disease (GVHD) prophylaxis regimen has not been established for patients undergoing reduced intensity allogeneic hematopoetic stem cell transplantation (HSCT) from matched unrelated donors (URD). Encouraging results have been reported with both the combination of alemtuzumab and cyclosporine (AC) and the regimen of tacrolimus, methotrexate, and sirolimus (TMS) in the URD setting. These two regimens work by biologically distinct mechanisms and may have markedly different effects on immune reconstitution. T-cell receptor (TCR) spectratyping analysis, which provides information on antigen receptor diversity, is a valuable method for monitoring post-transplant immune reconstitution. As part of a randomized pilot study, we prospectively assessed the effects of AC vs. TMS on TCR Vb repertoire diversity in patients undergoing reduced intensity HLA-matched unrelated donor transplantation. Methods: Twenty patients (median age 53 yrs; range 24–70 yrs) with hematologic malignancies received reduced intensity conditioning (fludarabine 30 mg/m2/day and cyclophosphamide 1200 mg/m2/day IV Day -6 to -3) followed by a 10/10 HLA-matched unrelated donor T-cell replete mobilized peripheral blood allograft. Patients were randomized to receive either: AC (n=10): alemtuzumab 20 mg/day IV over 8 hours Days -8 to -4 and cyclosporine starting at Day -1 with a 10% per week taper starting at Day +100 or TMS (n=10): tacrolimus and sirolimus starting at Day -3 with a 33% taper at Day +63 and Day +119 and methotrexate 5 mg/m2 IV, Days +1, +3, +6, and +11. Blood samples were collected from the donor and patient at baseline and the patient at 1, 3, 6 and 12 months post-transplant for TCR spectratyping analysis. All comparisons are based on an exact Wilcoxon rank sum test; p values < 0.01 were significant because of multiple comparisons. Results: Patients on the AC arm had significantly fewer T-cells on Day +14 compared with the TMS arm (median CD3+ = 1 cells/μl vs 356 cells/μl; CD4+ = 0 cells/μl vs 243 cells/μl; CD8+ = 0 cells/μl vs. 59 cells/μl; each p<0.0001); there was less disparity at Day +28 (median CD3+ = 45 cells/μl vs. 398 cells/μl; CD4+ = 36 cells/μl vs. 218 cells/μl; CD8+= 5 cells/μl vs 152 cells/μl; each p 0.002). By Day +100, lymphocyte recovery was not appreciably different between the two arms (median CD3+ = 242 cells/μl vs. 445 cells/μl (p = 0.095): CD4+ = 106 cells/μl vs. 212 cells/μl (p=0.28); CD8+ = 72 cells/μl vs. 135 cells/μl (p = 0.03). NK-cell recovery was slightly less in the AC vs. TMS arm at Day +14 (median NK = 27 cells/μl vs. 70 cells/μl; p = 0.01) and at Day +28 (median NK = 29 cells/μl vs. 150 cells/μl; p=0.02). There was no difference by Day +100 (median NK = 124 cells/μl vs. 88 cells/μl; p=0.31). B-cell reconstitution was negligible in both arms through Day +100. Assessment of CD4+ TCR Vb repertoire diversity by spectratyping demonstrated significantly lower diversity in patients receiving AC at 1 (p = 0.0003), 3 (p = 0.0003) and 6 (p=0.003) months post transplant compared with patients receiving TMS. CD8+ TCR spectratyping similarly revealed significantly reduced diversity in the AC arm at 3 (p = 0.001) and at 6 months (p = 0.003), and a trend toward significance at 12 months (p = 0.07). On each of the 2 arms, 2 of 10 patients developed acute Grade II-IV GVHD. Of the 5 patients on the AC arm who were seropositive for CMV, all 5 reactivated CMV by PCR within the first 60 days and reactivated 2–5 times in the first year. In contrast, only 3 of 5 seropositive patients reactivated CMV on the TMS arm and only one reactivated in the first 60 days. Conclusions: Two factors may have contributed to the loss of repertoire diversity in the AC arm. First, the alemtuzumab regimen may have severely depleted the infused donor T-cells. Second, stimulation by reactivating virus may have induced expansion of CMV-specific memory and effector T-cells, resulting in a skewed and oligoclonal T-cell repertoire. Especially in CD8+ T-cells, CMV has been shown to produce significant oligoclonal expansion (including CD4+: CD8+ ratio inversion). The loss of T-cell numbers and repertoire may in turn have contributed to the prevalence of early CMV reactivation. Thus, despite the similarities in frequency of acute GVHD in this small sample, it appears that these two commonly used GVHD prophylaxis regimens have very different effects on post-transplant immune reconstitution in the first 6 months after allogeneic HSCT. Disclosures: No relevant conflicts of interest to declare.

Comparison of Early Post-Transplant Outcomes in Ex Vivo αβ+ T Cell-Depleted Haploidentical HSCT with or without Pharmacologic Gvhd Prophylaxis

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3379-3379 ◽  
Author(s):  
Eun Seok Choi ◽  
Sung Han Kang ◽  
Hyery Kim ◽  
Kyung-Nam Koh ◽  
Ho Joon Im ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Acute Gvhd ◽  
Ex Vivo ◽  
Post Transplant ◽  
Cell Dose ◽  
Gvhd Prophylaxis ◽  
The Mean ◽  
Mean Time ◽  
Αβ T Cells

Abstract Background and purpose: One of the key obstacles to successful haploidenitcal hematopoietic cell transplantation (HHCT) is a development of fatal GVHD. Although much progress in immunosuppressant (IS) has effectively prevented the development of acute GVHD, they have many serious toxicity and drug interactions requiring serial monitoring of drug levels. Recent advances in ex vivo depletion technique enabled to effectively reduce T cells or their subset, αβ+ T cells, leading to residual αβ+ T cells in grafts well below 5×104/kg of recipient weight. We eliminated post-transplant pharmacologic GVHD prophylaxis along with targeting αβ+ T cell dose ≤ 5×104/kg since November 2015. In this study, we compared early post-transplant outcomes between with (IS+) or without (IS-) post-transplant immunosuppressants after ex vivo αβ+ T cell-depleted HHCT. Methods: Between May 2012 and July 2016, 69 pediatric patients received HHCT using TCRαβ-depleted grafts from haploidentical family donors at Asan Medical Center Children's Hospital. Fifty patients received tacrolimus and mycophenolate mofetil to prevent acute GVHD, while 19 did not receive any immunosuppressant after transplant. All donors received G-CSF for 4 consecutive days and peripheral blood stem cells were collected on days -1 and 0. The αβ+ T cells were depleted by negative selection using the CliniMACS® system (Miltenyi-BioTec, Bergisch-Gladbach, Germany) according to manufacturer's instruction. In the earlier trial of IS+, the final doses of αβ+ T cells were adjusted to 1-5×105 cells/kg by add-back from the raw bag. Since November 2015, the cell dose was targeted at ≤ 5×104 αβ+T cells/kg with no post-transplant immunosuppressants (IS-). Results: The median infused CD34+ cells, αβ+ T cells, γδ+ T cells and CD3-CD56+ NK cells per kg of recipient weight were 8.9×106, 33.8×104, 20.0×106, 45.9×106 in IS+ group and 6.1×106, 4.6×104, 17.5×106, 24.6×106 in IS- group, respectively. All 69 patients achieved neutrophil engraftment at a median of 10 days (range, 9-17). Three patients out of 50 in IS+ group experience graft rejection (GR), while no GR occurred in IS- group. The cumulative incidences of acute GVHD grade II-IV were similar (31% vs 33%). Severe acute GVHD ≥ grade III developed in 7 in IS+ group, while none in IS- group developed ≥ grade III. As of July 2016, the median follow-ups were 24 months (range 9.5-50.8) for IS+ group and 5 months (0.5-9.1) for IS- group. Two out of 50 patients in IS+ group died of TRM leading to 2.2% at 6 months and 4.9% at 1 year after HHCT, while no patients in IS- group died of TRM during the follow-up period. The mean time from transplant to discharge were longer in IS+ group compared to IS- group (32 days versus 21 days, P=0.049). While the mean time of hospital stay within 100 days post-HHCT for patients who survived more than 100 days was not different between two groups (47 days versus 34 days, P>0.05). Conclusions: The major findings of our study were less severe acute GVHD and shorter hospital stay from HHCT to discharge in IS- group, even with less T cell dose, compared to IS+ group. Therefore, this HHCT using ex vivo αβ-depleted graft containing αβ+ T cells ≤ 5×104/kg is an effective treatment strategy to prevent acute GVHD without post-transplant IS. In addition, the early clinical outcomes were comparable between with and without post-transplant IS. Disclosures No relevant conflicts of interest to declare.

scholarly journals Post-Transplant Cyclophosphamide Ameliorates Lethal Thymic GVHD By Restoring Regulatory and Effector T Cell Homeostasis in Recipients with Prior PD-1 Blockade Therapy

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 479-479
Author(s):  
Shuntaro Ikegawa ◽  
Yusuke Meguri ◽  
Takumi Kondo ◽  
Hiroyuki Sugiura ◽  
Yasuhisa Sando ◽  
...  
Keyword(s):  
Overall Survival ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Reconstitution ◽  
T Cell Subsets ◽  
Post Transplant ◽  
Gvhd Prophylaxis ◽  
Donor T Cells ◽  
The Impact

Abstract Allogeneic HSCT has a curative potential for patients with hematological malignancies. However, graft-versus-host disease (GVHD) remains to be a significant cause of morbidity and mortality after HSCT. Regulatory T cells (Tregs) are critical mediator for immune tolerance after HSCT and we recently reported that PD-1 plays an essential role for Treg survival (Asano et al, Blood 2017). Clinical studies suggested that PD-1 blockade prior to HSCT could be a risk of increasing severe GVHD. However, the mechanisms about GVHD induced by PD-1 blockade have largely unclear and there remains a paucity of data on appropriate GVHD prophylaxis for patients who undergo HSCT after PD-1 blockade. To address these issues, we investigated the impact of PD-1 expression on donor T cells on immune reconstitution with murine BMT models. First, lethally irradiated B6D2F1 mice were transplanted with 10 million of C57BL/6-background PD-1+/+ or PD-1-/- spleen cells with 5 million of bone marrow cells from normal C57BL/6, and GVHD scores and overall survival was monitored. Recipients receiving PD-1-/- graft developed severe GVHD resulting in a significant shorter survival than recipients receiving PD-1-/- graft (P<0.0001). We analyzed lymphocytes in spleen and thymus on day3, 7, and 14. We found that CD8 T cells in PD-1-/- group showed markedly higher Ki67 expression and CFSE-dilution until day3. Interestingly, PD-1-/- Tregs increased aggressively at day3 but it could not maintain until day14, while PD-1-/- CD8 T cells and conventional CD4 T cells (CD4 Tcons) continued to increase until day+14, resulting in the significant higher CD8/Treg ratio in PD-1-/- group (P<0.05, vs PD-1+/+ group). PD-1-/- Tregs showed significantly higher expression of Annexin V on day+7 and thymus CD4- and CD8- double-positive (DP) cells were in the extremely low levels in PD-1-/- group on day+14 (P<0.05, vs PD-1+/+ group). Thymic analysis showed that donor PD-1-/- graft-derived CD8 T cells infiltrated thymus in PD-1-/- group, suggesting reconstruction of thymic function was critically disturbed by severe GVHD. These data suggest that loss of PD-1 signaling resulted in unbalanced reconstitution of donor-derived T cell subsets as a consequence of continuous CTL expansion and increased Treg apoptosis. Next, to evaluate the impact of post-transplant cyclophosphamide (PTCy) on the abnormal reconstitution after PD-1 blockade, we administered 50mg/kg of Cy or control vehicle on day3. PTCy efficiently ameliorated GVHD in PD-1-/- group and extended overall survival by safely regulating the proliferation and apoptosis of T cell subsets. Of note, after PTCy, Tregs regained the ability of continuous proliferation in the first 2 weeks, resulting in well-balanced reconstitution of donor-derived T cell subsets. Thymic DP cells on day 14 was markedly increased in PD-1-/- group with PTCy intervention as compared to without PTCy, suggesting PTCy could rescue thymus from PD-1 blockade-related severe GVHD. Finally, to evaluate GVL activity, we performed BMT with co-infusion of P815L tumor cells on day0 and we confirmed that PTCy treatment for PD-1-/- recipients reduced the severity of GVHD with maintaining sufficient GVL effect. In summary, our data suggested three insights about the impact of PD-1 signaling on immune reconstitution. First, PD-1 inhibition influenced graft-derived T cells very differently within T cell subsets. PD-1-/- Tregs increased transiently but it was counterbalanced by accelerated apoptosis, while PD-1-/- CD4+Tcons and CD8 T cells continued the drastic expansion. Second, we found that PD-1-/- donor T cells developed severe GVHD in thymus. Few reports have concentrated on the impact of donor graft PD-1 expression to thymus after BMT and acute GVHD in thymus could lead late central immune disturbance. Third, PTCy successfully ameliorated GVHD induced by PD-1-/- donor T cells preserving GVL effect. Cell proliferation study implied that PD-1-/- graft-derived CD8 T cells might be more susceptible for PTCy because of the high-rate proliferation. In conclusion, PD-1-/- graft cause lethal thymic GVHD and PTCy successfully ameliorated it. The influence of PD-1 inhibition was different within T cell subtypes. PTCy might be appropriate GVHD prophylaxis strategy for patients who had prior usage of PD-1 blockade. Disclosures No relevant conflicts of interest to declare.

A Role for Regulatory Cells in Tolerance Induction in Recipients of Haploidentical Combined Non-Myeloablative Bone Marrow and Kidney Transplantation?.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3255-3255
Author(s):  
Giovanna Andreola ◽  
Meredith Chittenden ◽  
Juanita Shaffer ◽  
A. Benedict Cosimi ◽  
Tatsuo Kawai ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Conditioning Regimen ◽  
Tolerance Induction ◽  
In Vitro Assays ◽  
Mixed Chimerism ◽  
Post Transplant ◽  
Hla Dr

Abstract Following an in vivo T cell depleting non-myeloablative conditioning regimen, 5 patients, aged 22–49, received combined kidney and bone marrow transplantation from a haploidentical related donor. Rituximab was included in the conditioning for patients 4 and 5. All patients developed initial mixed chimerism but lost it by day 21; no patient developed GVHD. Four patients discontinued immunosuppression from 240 to 422 days after BMT and have remained off immunosuppression for 9 to 52 months with no evidence of allograft rejection. Flow cytometry was used to assess lymphocyte subsets recovering after transplant. CD3 counts recovered slowly, exceeding 500 cells/μl at days +271, +365, +640 and +450. While memory CD45RO+ cells were most prevalent among CD4+ cells, naïve-type CD4+CD45RA+ cells, presumably arising from the recipient thymus, ranged from 8% to 56% at the time when total CD4 counts recovered to >100 cells/μl (days +165, +21, +352, +240). Notably, a very high proportion of initially recovering T cells were CD3+CD4+ expressing CD25 in all patients as early as day 7 and persisted over 1 year in 2 patients. At approximately day +120 and +365, we further characterized these cells for CD127, FOXP3, CD45RO, CD45RA, HLA-DR and CD62L expression. At Day +120, all 4 patients showed increased frequencies (10.7±4.6%) of CD25+CD127-FOXP3+ regulatory T cells (Treg) within the CD4 population compared to healthy subjects (3.8±0.4%). Expression of CD45RO, CD45RA, CD62L and HLA-DR was variable. By 1 year post-transplant, frequencies of Treg had decreased to levels similar to those in normal subjects. In vitro assays for CD8 and CD4 T cell-mediated alloreactivity (CML/MLR) showed development of long-lasting donor-specific unresponsiveness by 3 months after transplant in Patients 2, 4 and 5, and by 9 months in Patient 1. Responses to 3rd party recovered in all patients after a period of unresponsiveness. In Patient 1, in whom anti-donor CML reactivity declined gradually to become unresponsive by 9 months, depletion of CD4+CD25+ cells revealed a residual anti-donor CML and MLR response at 1year but not at 18 months. In 2 other patients, depletion of CD4+CD25+ cells did not reveal an anti-donor response at time points analyzed from day +122 to 2 years. In patients in whom renal tubular epithelial cells (RTEC) were cultured from the donor kidney, loss of killing activity against donor RTEC was observed post-transplant. The high percentage of Treg recovering early after transplant suggests that they may play a role in initial tolerance induction. This regulatory mechanism may be followed by later deletion of donor-reactive T cells. The variable ability to detect regulation of anti-donor reactivity may reflect the strength of the initial response, as patients with weak pre-transplant anti-donor responses and rapid post-transplant development of donor unresponsiveness did not reveal anti-donor response when Treg were depleted. In addition, infiltration of Treg at the graft site, not revealed by the assays described, might be responsible for tolerance in these patients.

Natural Killer Cell Reconstitution after Haploidentical Hematopoietic Stem Cell Transplantation with Post-Transplant Cyclophosphamide: Elimination of Donor-Derived Mature Alloreactive NK Cells, but Favorable Conditions for Adoptive Immunotherapy

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4567-4567
Author(s):  
Antonio Russo ◽  
Giacomo Oliveira ◽  
Sofia Berglund ◽  
Raffaella Greco ◽  
Valentina Gambacorta ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Hematopoietic Stem Cell Transplantation ◽  
Nk Cells ◽  
Proliferating Cells ◽  
Hematopoietic Stem ◽  
Post Transplant ◽  
Gvhd Prophylaxis

Abstract INTRODUCTION The use of high-dose cyclophosphamide as post-transplant Graft versus Host Disease (GvHD) prophylaxis has revolutionized haploidentical hematopoietic stem cell transplantation (haplo-HSCT), allowing the safe infusion of T cell replete grafts. The efficacy of post-transplant cyclophosphamide (PT-Cy) has its basis in its capacity to selectively eliminate proliferating cells, including alloreactive T cells. It is however to date unknown whether PT-Cy affects the reconstitution of Natural Killer (NK) cells, whose alloreactivity is known to play a major role in T cell-depleted haplo-HSCT. PATIENTS AND METHODS We analyzed the grafts and serial peripheral blood (PB) and bone marrow (BM) samples from 14 patients who received T cell replete haplo-HSCT followed by PT-Cy at the San Raffaele Scientific Institute, Milan (n=10, OSR) or the Johns Hopkins University, Baltimore (n=4, JHU). OSR patient received a myeloablative conditioning, PB stem cell grafts, and sirolimus and mycophenolate as pharmacological GvHD prophylaxis. JHU patients received the "classical" Baltimore nonmyeloablative conditioning, unmanipulated BM grafts, and tacrolimus and mycophenolate as pharmacological GvHD prophylaxis. To characterize NK cells reconstitution, we monitored absolute counts and employed a 27-marker flow cytometry panel with high dimensional single-cell analysis using the bh-SNE algorithm. We used intracellular staining to determine the frequency of Ki67+ proliferating cells and expression of Aldehyde Dehydrogenase (ALDH), known to confer resistance to PT-Cy. Interleukin-15 (IL-15) serum concentration was quantified using the Bio-Plex Pro Human Cytokine 4-plex assay. To directly assess the effect of PT-Cy on proliferating NK cells we exposed graft NK cells to IL-15 and mafosfamide, a cyclophosphamide analogue active in vitro. Functional assays against leukemic cell lines and primary AML blasts were performed measuring CD107A degranulation on NK cells and Annexin V on targets. RESULTS All patients received high numbers of mature donor NK cells as part of the graft (OSR median 17x106/kg, JHU median 7.25x106/kg ), and donor-derived NK cells were detectable as early as day 3 after HSCT and throughout the entire follow-up. At day 3 after HSCT, all subsets of NK cells, including single KIR+ alloreactive cells, were actively proliferating (mean 61.23% of Ki-67+ cells for OSR patients, and 58% for JHU patients), possibly driven by the high levels of IL-15 detected in patient serum after conditioning (Fig.1A). After PT-Cy, a marked reduction in the frequency and counts of proliferating NK cells was evident irrespectively of the transplantation platform, suggesting selective killing of dividing cells by PT-Cy. In line with this hypothesis, NK cells from the graft and from patient PB at day 3 after HSCT showed no detectable ALDH expression, and NK cells prompted to proliferate in vitro were killed in a dose-dependent manner by mafosfamide (Fig.1B). The phenotype of NK cells also changed upon PT-Cy: whereas before the infusion they resembled their mature counterparts from the graft, after PT-Cy an immature phenotype, CD62L+NKG2A+KIR-, became prevalent, suggesting derivation from donor HSCs rather than from infused NK cells (Fig.1C). Accordingly, bhSNE maps demonstrated differential clustering of NK cells from the graft and analyzed 30 days after HSCT (Fig.1D). In line with these features, we detected very low numbers of putatively alloreactive single KIR+ NK cells both in the PB and in the BM of patients at day 30 after HSCT, and these NK cells displayed impaired cytotoxic potential against leukemic targets. Finally, consistent with these observations, when we analyzed the impact of predicted NK alloreactivity in an extended series of 99 patients who received myeloablative haplo-HSCT with PT-Cy, we detected no significant difference in progression-free survival (Fig.1E). CONCLUSION Our data suggest that the majority of mature NK cells infused with unmanipulated grafts are eliminated upon PT-Cy administration and that in this transplantation platform NK cell alloreactivity might be blunted by the elimination of donor single KIR+ NK cells and by the competition between reconstituting NK and T cells. Still, the high levels of IL-15 detected in patients' sera at early time-points might provide a biological rationale for the infusion of mature donor NK cells early after PT-Cy administration. Figure 1 Figure 1. Disclosures Bonini: TxCell: Membership on an entity's Board of Directors or advisory committees; Molmed SpA: Consultancy. Ciceri:MolMed SpA: Consultancy.

scholarly journals Development of immunosuppressive myeloid cells to induce tolerance in solid organ and hematopoietic cell transplant recipients

2021 ◽  
Author(s):  
Kent P Jensen ◽  
David Hongo ◽  
Xuhuai Ji ◽  
Pingping Zheng ◽  
Rahul D Pawar ◽  
...  
Keyword(s):  
Clinical Trials ◽  
T Cells ◽  
Conditioning Regimen ◽  
Myeloid Cells ◽  
Hematopoietic Cell ◽  
Mixed Chimerism ◽  
Solid Organ ◽  
Cell Transplant ◽  
Hematopoietic Cell Transplant ◽  
Post Transplant

Replacement of failed organs followed by safe withdrawal of immunosuppressive drugs have long been the goals of organ transplantation. We studied changes in the balance of T and myeloid cells in blood of HLA-matched and -mismatched patients given living donor kidney transplants (KTx) followed by total lymphoid irradiation (TLI), anti-thymocyte globulin (ATG) conditioning, and donor hematopoietic cell transplant (HCT) to induce mixed chimerism and immune tolerance. The clinical trials were based on a conditioning regimen used to establish mixed chimerism and tolerance in mice. In pre-clinical murine studies, there was a profound depletion of T cells and an increase in immunosuppressive, polymorphonuclear (pmn), myeloid derived suppressor cells (MDSCs) in the spleen and blood following transplant. Selective depletion of the pmn-MDSCs in mice abrogated mixed chimerism and tolerance. In our clinical trials, patients given an analogous tolerance conditioning regimen developed similar changes including profound depletion of T cells and a marked increase in MDSCs in blood post-transplant. Post-transplant pmn-MDSCs transiently increased expression of lectin-type, oxidized LDL receptor-1 (LOX-1), a marker of immunosuppression, and production of the T cell inhibitor, arginase-1. These post-transplant pmn-MDSCs suppressed the activation, proliferation, and inflammatory cytokine secretion of autologous, TCR microbead-stimulated, pre-transplant T cells when co-cultured in vitro. In conclusion, we elucidated changes in receptors, and function of immunosuppressive myeloid cells in patients enrolled in the tolerance protocol that were nearly identical to the that of MDSCs required for tolerance in mice. The clinical trials are registered in Clinicaltrials.gov under NCT #s 00319657 and 01165762.

Identification of a Single MiHA Specificity That Induces Resistance to MHC-Matched Allogeneic HCT.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3216-3216
Author(s):  
Alwi M. Shatry ◽  
Robert B. Levy
Keyword(s):  
T Cells ◽  
T Cell ◽  
Donor Cell ◽  
Hematopoietic Cell ◽  
Cell Transplant ◽  
Hematopoietic Cell Transplant ◽  
Post Transplant ◽  
Single Donor ◽  
Donor Cells ◽  
Allogeneic Marrow

Abstract T cell populations specific for transplantation antigens have been detected in sensitized individuals following multiple blood transfusions, marrow transplants as well as in multiparous females. Resistance to allogeneic hematopoietic cell transplant (HCT) in such sensitized individuals is consistent with the presence of a host memory T cell (TM) population specific for donor cell antigens. We hypothesized that a single donor minor histocompatibility (MiHA) epitope could elicit antigen-specific CD8 TM capable of resisting MHC-matched allogeneic hematopoietic cell engraftment. To address this question, CD8 TM were generated against a single MiHA epitope to determine if such cells could mediate resistance after ablative TBI conditioning. B6 mice were sensitized 2X to the H60 immunodominant MiHA epitope utilizing bone marrow-derived dendritic cells pulsed with the H60 (LTFNYRNL) peptide. Three weeks following booster sensitization, CD8 T cells were detected by tetramer staining in peripheral blood samples. These T cells exhibited a phenotype characteristic of memory cells (CD44hi, Ly 6C+). B6 (H2b) mice containing CD8+ H60+ T cells were subsequently conditioned with 9.0 Gy TBI and transplanted with 5 × 106 BALB.B (H2b) BM-TCD. One week post-transplant, naive recipients of BALB.B (H60+) or B6-H60 congenic TCD-BM contained >10-fold higher levels of circulating donor cells than the B6 dendritic cell/peptide sensitized recipients. Donor progenitor cells were also found to be significantly reduced in sensitized recipients of allogeneic TCD-BM at this time. Two weeks post-HCT, recipients of syngeneic marrow exhibited >10-fold greater frequency of circulating donor cells compared to recipients of MHC-matched allogeneic marrow (< 5% donor chimerism was detected). These findings demonstrate that host T cells with specificity against a single donor MiHA determinant are sufficient to induce resistance to MHC-matched allogeneic marrow engraftment. Such observations regarding the effector response of HVG contrast those by donor T cell responses post-transplant in which single MiHA differences fail to induce GVHD. Finally, heterologous immunity to virus has been reported to generate allo-reactive TM cells. Since such TM repertoires could include specificity for MiHA immunodominant epitopes, the presence of TM populations that can mediate resistance in “naive” recipients may be more prevalent than hitherto appreciated.

Excellent Engraftment and Reduced Acute and Chronic Graft Versus Host Disease (GVHD) in ATG-Refractory Severe Aplastic Anemia (SAA) Following Transplantation of a PBSC Allograft Containing CD34+ Selected Cells Combined with Non-Mobilized Donor T-Cells

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3882-3882
Author(s):  
Enkhtsetseg Purev ◽  
Xin Tian ◽  
Jeremy M Pantin ◽  
Robert N Reger ◽  
Lisa Cook ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Bone Marrow Failure ◽  
Chronic Gvhd ◽  
Historical Cohort ◽  
Post Transplant ◽  
Bone Marrow Failure Syndromes ◽  
Cell Engraftment ◽  
Gvhd Prophylaxis

Abstract Introduction: The risk of graft-rejection after allogeneic hematopoietic cell transplantation using bone marrow and conventional cyclophosphamide-based conditioning is increased in HLA allo-immunized and heavily transfused patients with bone marrow failure syndromes. Recently, we showed that fludarabine-based peripheral blood stem cells transplantation (PBSCT) overcomes the risk of graft-failure in patients with SAA who have failed immunosuppressive therapy (IST). However, this approach was complicated by a high incidence of acute and chronic GVHD. Multivariate analysis showed rapid donor T-cell engraftment (defined as >= 95% donor T-cell chimerism by post-transplant day 30) significantly increased the risk of cGVHD. Based on these data, we developed a novel transplant approach in which a G-CSF mobilized PBSC allograft that was T-cell depleted and CD34+ selected was co-infused with a bone marrow transplant (BMT)-equivalent dose of non-mobilized donor T-cells to facilitate donor engraftment and reduce GVHD by delaying the speed of donor T-cell engraftment. Method: Patients with transfusion-dependent SAA, refractory to conventional IST, underwent allogeneic PBSCT following cyclophosphamide (60 mg/kg/d IV x 2 days), equine antithymocyte globulin (hATG; 40 mg/kg/d IV x 4 days), and fludarabine (25 mg/m2/d IV x 5 days) conditioning. On day 0, patients received a G-CSF mobilized PBSC allograft from an HLA identical sibling, containing CD34+ selected cells (MiltenyiCliniMACS system: target CD34+ cell dose 8 x 106 cells/kg and target T-cell dose < 3 x 105 cells/kg) combined with 2 x 107CD3+ T-cells/kg that had been collected by apheresis and cryopreserved from the same donor prior to G-CSF mobilization. CSA and mini-dose MTX (5 mg/m2 IV on days 1, 3, 6) were used as GVHD prophylaxis. Transplant outcomes were compared to our historical cohort of patients (n=56) with SAA and other bone marrow failure syndromes who received a T-cell replete PBSC from an HLA matched donor following the identical conditioning and GVHD prophylaxis regimens. Results: 11 patients with SAA were transplanted. Patients were heavily transfused and highly allo-immunized; the pre-transplant serum ferritin level was markedly elevated at a median 3003 µg/L (range 286 to 13928 µg/L) and 7 patients (64%) were HLA allo-immunized with a median 21% (HLA class I) and 31% (HLA class II) panel-reactive antibodies. All 11 patients (100%) engrafted. The median time to neutrophil and platelet recovery was 14 (range 12 to 23) and 18 (range 14 to 321) days respectively. All patients achieved full and sustained donor T-cell chimerism and myeloid chimerism, which occurred at a median 45 and 15 days post-transplant, respectively. Among those at risk, 6/7 (86%) developed CMV reactivation. EBV reactivation occurred in all cases, including 5 who received preemptive treatment with rituximab. At a median follow-up of 2 years, only 1 patient (9%) has developed acute and another (9%) developed cGVHD (limited, skin). Neither corticosteroid-refractory aGVHD nor extensive cGVHD occurred. Long-term survival was excellent; 10 of 11 patients (91%) survived to day 200; at a median follow-up of 2.7 years, 9/11 (80%) survive. One patient died on day 46 from Klebsiella Pneumoniae carbapenemase bacteremia, which predated the transplant, and another died 18 months post-transplant from bacterial pneumonia. Compared to our historical cohort of marrow failure patients who received a T-cell replete PBSC allograft, patients receiving CD34+ selected cells combined with non-mobilized T-cells (partially T cell depleted PBSC) had similar survival (80% vs 87%;p=0.5), a delay in the time to achieving full donor T-cell chimerism (45 days vs 30 days; p=0.046) and dramatic reductions in both acute grade II-IV GVHD (9% vs 52%; p=0.017) and cGVHD (1 year incidence 9% vs 63%; p=0.002). Conclusion: In SAA, transplantation of a PBSC allograft containing high numbers of CD34+ selected cells co-infused with a BMT-equivalent dose of non-mobilized T-cells results in excellent engraftment and reduces acute and chronic GVHD by delaying the speed of donor T-cell engraftment. Figure: Figure:. Disclosures Townsley: GSK: Research Funding.

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