Reduction in Incidence of Severe Infections by Transplantation of High Doses of Haploidentical T Cells Selectively Depleted of Alloreactive Units

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3020-3020 ◽  
Author(s):  
Denis-Claude Roy ◽  
Mireille Guerin ◽  
Radia Sidi Boumedine ◽  
Silvy Lachance ◽  
Sandra Cohen ◽  
...  

Abstract Abstract 3020FN2 Background: The intensive T-cell depletion of the graft accompanying haploidentical stem cell transplantation (SCT) delays immune reconstitution and results in frequent and rapidly lethal infectious complications. The ability to accelerate immune reconstitution following HLA-haploidentical-SCT would extend safe transplantation to the large number of patients who do not have an HLA-matched donor. Methods: Twenty-seven adults with very high-risk malignancy entered a Phase I clinical trial of haplo-identical T-cell depleted allogeneic SCT followed by an immunotherapeutic strategy consisting of alloreactive T-lymphocyte depleted cells to accelerate immune reconstitution (ATIR) while preventing graft-versus-host disease (GVHD). Selective elimination of host-reactive T cells was achieved using a dibromorhodamine-based photodepletion approach. All stem cell grafts underwent in vitro immunomagnetic T cell depletion using CD34+ positive cell selection (Miltenyi). The myeloablative regimen consisted of TBI (1200 cGy), thiotepa (5 mg/kg), ATG (12.5 mg/kg) and fludarabine (200 mg/m2). No GVHD prophylaxis was administered. Results: Eight patients were enrolled and subsequently removed from the study because of leukemia relapse (n=4) or late identification of an unrelated donor (n=4). All 8 patients died. Nineteen patients (11 M, 8 F) with very high-risk hematologic malignancies (mostly refractory or relapsed acute myeloid leukemia (10) and myelodysplastic syndromes (4), and refractory biphenotypic leukemia (1), CLL (2), CML (1) and NHL (1)) proceeded with the trial. Median age was 54 years (range: 20–62). Patient and disease characteristics were similar between patient cohorts. Patients received incremental doses of ATIR cells, from 1×104 to 5×106 CD3 cells/kg at a median of 30 days (range: 28–39) after SCT. Greater than 90% of activated (CD25+CD44+) CD4 and CD8 T cells (p<0.004) and anti-host cytotoxic T lymphocyte precursors (CTLp) (p=0.0008) were depleted from the donor lymphocyte infusions (DLI). Interferon- γ responses against CMV, EBV and Influenza peptides were maintained post-photodepletion. Naive (TNaive) and central memory (TCM) T cells were also preserved, but mature effector memory populations (TEMRA) decreased after photodepletion. All patients showed complete donor chimerism and durable hematologic engraftment. No patients developed grade III-IV acute GVHD. Acute GVHD grade II developed in 4 patients at a median of 102 days post-transplant (range 45–125), 3 of these belonging to the 2 highest dose groups (2.0–5.0×106 CD3 cells/kg). Five patients developed de novo extensive chronic GVHD at a median of 4.8 months post-transplant. All patients responded rapidly to oral immunosuppression lasting for a median of 6.3 months, with only one patient treated for up to 17 months. NK (CD56) and B (CD19) cells were the first to recover, approximately 4 weeks post-transplant. Patients administered the highest T-cell doses (2.0–5.0×106 CD3 cells/kg) showed earlier reconstitution of CD3, CD4 and CD8 cells (all p≤0.02). The administration of increasing ATIR cell doses yielded gradually increasing proportions of TNaive of CD4 phenotype in the first 18 weeks, and of CD8 phenotype between weeks 18 and 36 post-ATIR. Time to the first infection was delayed in patients receiving high ATIR doses (p=0.015). During the first 6 months post-ATIR, the number of patients without infections was only 1 (14%) of the 7 low T-cell doses patients but increased to 8 (67%) in the high T-cell dose group (p=0.027). The overall survival was 47.4±22.4% (±95% confidence interval) and the event-free-survival 36.8±21.7% at 2 years, with a median follow-up of survivors of 4.0 years (range 3.1–5.1 years). Transplant-related mortality was decreased in the high (19.2%) versus the low ((65.7%) T-cell dose group, with a similar trend for improved survival in the high T-cell dose group (p=0.078). Conclusions: Post-transplant immunotherapy with photodepleted DLI decreased the incidence and severity of infections without inducing severe GVHD. These results document the benefits of administrating selectively depleted T-cells after haploidentical transplantation. Disclosures: Roy: Kiadis Pharma: Research Funding. Mielke:Kiadis Pharma: Research Funding. Egeler:Kiadis Pharma: Employment.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3379-3379 ◽  
Author(s):  
Eun Seok Choi ◽  
Sung Han Kang ◽  
Hyery Kim ◽  
Kyung-Nam Koh ◽  
Ho Joon Im ◽  
...  

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.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 43-44
Author(s):  
Amandine Pradier ◽  
Adrien Petitpas ◽  
Anne-Claire Mamez ◽  
Federica Giannotti ◽  
Sarah Morin ◽  
...  

Introduction Allogeneic hematopoietic stem cell transplantation (HSCT) is a well-established therapeutic modality for a variety of hematological malignancies and congenital disorders. One of the major complications of the procedure is graft-versus-host-disease (GVHD) initiated by T cells co-administered with the graft. Removal of donor T cells from the graft is a widely employed and effective strategy to prevent GVHD, although its impact on post-transplant immune reconstitution might significantly affect anti-tumor and anti-infectious responses. Several approaches of T cell depletion (TCD) exist, including in vivo depletion using anti-thymocyte globulin (ATG) and/or post-transplant cyclophosphamide (PTCy) as well as in vitro manipulation of the graft. In this work, we analyzed the impact of different T cell depletion strategies on immune reconstitution after allogeneic HSCT. Methods We retrospectively analysed data from 168 patients transplanted between 2015 and 2019 at Geneva University Hospitals. In our center, several methods for TCD are being used, alone or in combination: 1) In vivo T cell depletion using ATG (ATG-Thymoglobulin 7.5 mg/kg or ATG-Fresenius 25 mg/kg); 2) in vitro partial T cell depletion (pTCD) of the graft obtained through in vitro incubation with alemtuzumab (Campath [Genzyme Corporation, Cambridge, MA]), washed before infusion and administered at day 0, followed on day +1 by an add-back of unmanipulated grafts containing about 100 × 106/kg donor T cells. The procedure is followed by donor lymphocyte infusions at incremental doses starting with 1 × 106 CD3/kg at 3 months to all patients who had received pTCD grafts with RIC in the absence of GVHD; 3) post-transplant cyclophosphamide (PTCy; 50 mg/kg) on days 3 and 4 post-HSCT. Absolute counts of CD3, CD4, CD8, CD19 and NK cells measured by flow cytometry during the first year after allogeneic HSCT were analyzed. Measures obtained from patients with mixed donor chimerism or after therapeutic DLI were excluded from the analysis. Cell numbers during time were compared using mixed-effects linear models depending on the TCD. Multivariable analysis was performed taking into account the impact of clinical factors differing between patients groups (patient's age, donor type and conditioning). Results ATG was administered to 77 (46%) patients, 15 (9%) patients received a pTCD graft and 26 (15%) patients received a combination of both ATG and pTCD graft. 24 (14%) patients were treated with PTCy and 26 (15%) patients received a T replete graft. 60% of patients had a reduced intensity conditioning (RIC). 48 (29%) patients received grafts from a sibling identical donor, 94 (56%) from a matched unrelated donor, 13 (8%) from mismatched unrelated donor and 13 (8%) received haploidentical grafts. TCD protocols had no significant impact on CD3 or CD8 T cell reconstitution during the first year post-HSCT (Figure 1). Conversely, CD4 T cells recovery was affected by the ATG/pTCD combination (coefficient ± SE: -67±28, p=0.019) when compared to the T cell replete group (Figure 1). Analysis of data censored for acute or chronic GVHD requiring treatment or relapse revealed a delay of CD4 T cell reconstitution in the ATG and/or pTCD treated groups on (ATG:-79±27, p=0.004; pTCD:-100±43, p=0.022; ATG/pTCD:-110±33, p&lt;0.001). Interestingly, pTCD alone or in combination with ATG resulted in a better reconstitution of NK cells compared to T replete group (pTCD: 152±45, p&lt;0.001; ATG/pTCD: 94±36, p=0.009; Figure 1). A similar effect of pTCD was also observed for B cells (pTCD: 170±48, p&lt;.001; ATG/pTCD: 127±38, p&lt;.001). The effect of pTCD on NK was confirmed when data were censored for GVHD and relapse (pTCD: 132±60, p=0.028; ATG/pTCD: 106±47, p=0.023) while only ATG/pTCD retained a significant impact on B cells (102±49, p=0.037). The use of PTCy did not affect T, NK or B cell reconstitution when compared to the T cell replete group. Conclusion Our results indicate that all TCD protocols with the only exception of PTCy are associated with a delayed recovery of CD4 T cells whereas pTCD of the graft, alone or in combination with ATG, significantly improves NK and B cell reconstitution. Figure 1 Disclosures No relevant conflicts of interest to declare.


Hematology ◽  
2003 ◽  
Vol 2003 (1) ◽  
pp. 350-371 ◽  
Author(s):  
A. John Barrett ◽  
Katayoun Rezvani ◽  
Scott Solomon ◽  
Anne M. Dickinson ◽  
Xiao N. Wang ◽  
...  

Abstract After allogeneic stem cell transplantation, the establishment of the donor’s immune system in an antigenically distinct recipient confers a therapeutic graft-versus-malignancy effect, but also causes graft-versus-host disease (GVHD) and protracted immune dysfunction. In the last decade, a molecular-level description of alloimmune interactions and the process of immune recovery leading to tolerance has emerged. Here, new developments in understanding alloresponses, genetic factors that modify them, and strategies to control immune reconstitution are described. In Section I, Dr. John Barrett and colleagues describe the cellular and molecular basis of the alloresponse and the mechanisms underlying the three major outcomes of engraftment, GVHD and the graft-versus-leukemia (GVL) effect. Increasing knowledge of leukemia-restricted antigens suggests ways to separate GVHD and GVL. Recent findings highlight a central role of hematopoietic-derived antigen-presenting cells in the initiation of GVHD and distinct properties of natural killer (NK) cell alloreactivity in engraftment and GVL that are of therapeutic importance. Finally, a detailed map of cellular immune recovery post-transplant is emerging which highlights the importance of post-thymic lymphocytes in determining outcome in the critical first few months following stem cell transplantation. Factors that modify immune reconstitution include immunosuppression, GVHD, the cytokine milieu and poorly-defined homeostatic mechanisms which encourage irregular T cell expansions driven by immunodominant T cell–antigen interactions. In Section II, Prof. Anne Dickinson and colleagues describe genetic polymorphisms outside the human leukocyte antigen (HLA) system that determine the nature of immune reconstitution after allogeneic stem cell transplantation (SCT) and thereby affect transplant outcomethrough GVHD, GVL, and transplant-related mortality. Polymorphisms in cytokine gene promotors and other less characterized genes affect the cytokine milieu of the recipient and the immune reactivity of the donor. Some cytokine gene polymorphisms are significantly associated with transplant outcome. Other non-HLA genes strongly affecting alloresponses code for minor histocompatibility antigens (mHA). Differences between donor and recipient mHA cause GVHD or GVL reactions or graft rejection. Both cytokine gene polymorphisms (CGP) and mHA differences resulting on donor-recipient incompatibilities can be jointly assessed in the skin explant assay as a functional way to select the most suitable donor or the best transplant approach for the recipient. In Section III, Dr. Nelson Chao describes non-pharmaceutical techniques to control immune reconstitution post-transplant. T cells stimulated by host alloantigens can be distinguished from resting T cells by the expression of a variety of activation markers (IL-2 receptor, FAS, CD69, CD71) and by an increased photosensitivity to rhodamine dyes. These differences form the basis for eliminating GVHD-reactive T cells in vitro while conserving GVL and anti-viral immunity. Other attempts to control immune reactions post-transplant include the insertion of suicide genes into the transplanted T cells for effective termination of GVHD reactions, the removal of CD62 ligand expressing cells, and the modulation of T cell reactivity by favoring Th2, Tc2 lymphocyte subset expansion. These technologies could eliminate GVHD while preserving T cell responses to leukemia and reactivating viruses.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2904-2904 ◽  
Author(s):  
R. Lowsky ◽  
K. Heydari ◽  
B. Sahaf ◽  
J. Shizuru ◽  
G. Laport ◽  
...  

Abstract Murine models of transplantation established that nonmyeloablative conditioning using repeated low doses of irradiation targeted to lymphoid tissues (TLI) and depletive anti-T cell antibodies protects against GVHD by skewing residual host T cell subsets to favor regulatory natural killer (NK) T cells that suppress GVHD by polarizing donor T cells toward secretion of non-inflammatory cytokines such as IL-4. We recently translated the murine protocol to a clinical study using non-myeloablative TLI and ATG host conditioning with HLA matched related and unrelated donors, and showed a marked reduction in the incidence of acute GVHD while retaining graft anti-tumor activity (Lowsky et al., in Press NEJM). Engrafted donor CD4+ T cells showed a marked increase in IL-4 production as compared to CD4+ T cells from controls. We now adapted the TLI and ATG nonmyeloablative host conditioning regimen to a clinical study of allogeneic HCT using haploidentical matched (3/6 HLA matched) related donors to determine if it will result in donor hematopoietic cell engraftment and also protect against acute GVHD. Blood derived hematopoietic progenitor cells were collected by apheresis from donors mobilized with G-CSF and the product was T cell depleted using CD34+ selection. CD3+ T cells were added back to the donor inoculum according to a dose escalation schedule. The initial T cell dose was 1 x105 CD3+ cell/kg with designated increments based on clinical outcomes of up to a maximum of 1 x107 CD3+ cells/kg. The desired CD34+ cell dose was >5 x 106 CD34+ cells/kg for all patients. Seven patients were transplanted; the median age was 53 years (range 27 to 61 years). Five patients had acute myelogenous leukemia, two with disease in remission and three not in remission at the start of TLI and ATG, one with myelodysplastic syndrome, and one with progressive peripheral T cell lymphoma. The median follow-up for all patients is 265 days with three of seven patients alive and free of disease at the last observation period. Sustained donor hematopoietic cell engraftment was achieved in three of three patients only after the T cell dose was increased to 1 x107 CD3+ cells/kg. No patient developed acute GVHD. None of the three patients receiving the highest dose of T cells had any invasive fungal or viral infections. Monitoring of sorted host T cell subsets before TLI and ATG, and immediately after but before the infusion of donor cells, revealed in five of five patients a highly significant skewing of residual host T cells favoring invariant NK T (CD3+ CD161hi Va24 +Vb11 +) cells. The mean absolute number of host CD3+, and CD4+ and CD8+ T cells decreased by 99, 163 and 121 fold, respectively, immediately after conditioning compared to the absolute numbers before the start of TLI and ATG, whereas the mean absolute number of invariant NK T cells decreased by only 11%. In conclusion, we have determined the conditions for successful hematopoietic cell engraftment using a non-myeloablative regimen of TLI and ATG that appears associated with a reduced aGVHD risk yet retained graft anti-tumor activity. As in the pre-clinical model, we show direct evidence that the low incidence of aGVHD is associated with a significant alteration in residual host T cell subsets markedly favoring invariant NK T cells.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 573-573
Author(s):  
Jian-Ming Li ◽  
Cynthia Giver ◽  
Doug McMillan ◽  
Wayne Harris ◽  
David L. Jaye ◽  
...  

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]


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3054-3054 ◽  
Author(s):  
Rachel B. Salit ◽  
Frances T. Hakim ◽  
Michael R. Bishop ◽  
Thea M. Friedman ◽  
Robert Korngold ◽  
...  

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.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 339-339
Author(s):  
Alan M Hanash ◽  
Jarrod A Dudakov ◽  
Guoqiang Hua ◽  
Margaret O'Connor ◽  
Lauren F. Young ◽  
...  

Abstract Abstract 339 There is little understanding of the maintenance and regeneration of epithelial tissues after allogeneic transplant. Most clinical strategies to limit epithelial damage from graft vs. host disease (GVHD) also limit post-transplant immune function. Damage to the gastrointestinal (GI) tract from GVHD is a major cause of morbidity and mortality, and damage to the thymus from pre-transplant conditioning and GVHD can impair immune reconstitution, predispose patients to infection, and increase the risk of relapse. Therefore, understanding of tissue damage and recovery could lead to strategies selectively protecting epithelial tissues, improving intestinal barrier function, and promoting immune reconstitution without worsening post-transplant immunosuppression. We have recently identified that IL-22 from recipient-derived innate lymphoid cells (ILC) is critical for promoting intestinal recovery from GVHD and for promoting thymic recovery from radiation/pre-transplant conditioning. IL-22 deficient mice demonstrated significantly reduced thymopoiesis after total body irradiation (TBI), and IL-22 deficient murine bone marrow transplant (BMT) recipients demonstrated increased GVHD mortality and intestinal histopathology, deficiency of the antimicrobial molecules Reg3γ and Reg3β, and loss of intestinal stem cells needed for epithelial recovery. The source of thymic and intestinal IL-22 was RORγ+CD3−NKp46−IL-7R+CCR6+ lymphoid-tissue-inducer-like cells. Similar to as had been observed in the thymus, intestinal ILC produced IL-22 in response to IL-23, which was upregulated after TBI (p<.05 small intestine, p<.001 large intestine). IL-22 was also upregulated in response to TBI, but not in p40-deficient mice lacking IL-23 (p<.05 small intestine, p<.01 large intestine). ILC were radioresistant, as lethal TBI led to a three-fold increase in the intestinal ILC:CD4 ratio (p<.05). Furthermore, recipient-derived ILC comprised more than 50% of intestinal lamina propria ILC three months after T cell-depleted BMT, well after donor myeloid reconstitution and after donor reconstitution of the intestinal T cell compartment as well (Figure 1). Although intestinal ILC could survive lethal TBI, they were significantly depleted by both MHC mismatched (B6BALB/c) and MHC matched (LPB6) GVHD. Similarly, GVHD led to depletion of thymic IL-22+ ILC and reduction in thymic IL-22 levels (p<.001). Thymic IL-22 was critical for maintaining thymopoiesis during GVHD, as IL-22 deficient BMT recipients demonstrated significantly greater loss of double positive (DP) thymocytes after MHC-mismatched BMT. We previously identified that IL-21 receptor (IL-21R) signaling contributes to the migration of alloreactive donor T cells to the GI tract and that IL-21R-deficent donor T cells mediate significantly reduced GI GVHD. Given the similar homing molecules involved in the migration of donor T cells to the GI tract and thymus in GVHD, we evaluated the role of IL-21 in thymic GVHD. Donor T cell IL-21R deficiency led to increased thymopoiesis and DP thymocytes (p<.001), but not in IL-22-deficient recipients. ILC evaluation indicated that this IL-22 dependency was because IL-21R-deficiencient donor T cells had a reduced capacity to eliminate thymic ILC during GVHD (Figure 2). Therefore, donor T cell IL-21 signaling was critical for the elimination of recipient thymic ILC during GVHD, and preservation of the ILC compartment allowed for the IL-22 mediated regeneration of thymopoiesis. Finally, we also found that administration of rIL-22 post-BMT could reverse the thymic damage caused by GVHD and elimination of ILC, restoring the numbers of DP thymocytes to a level similar to what was observed after T cell-depleted BMT. In summary, IL-22+ ILC are radioresistant and capable of regulating tissue-specific epithelial recovery after allogeneic BMT. However, recipient ILC are extremely sensitive to GVHD, leading to a loss of the IL-22-mediated recovery response. IL-21 blockade can prevent the elimination of recipient thymic ILC by donor T cells in GVHD, and IL-22 administration can restore the thymopoiesis that is lost in GVHD due to ILC elimination. Maintenance of epithelial function post-BMT is thus an active innate immune response requiring cooperation between both recipient stroma and recipient hematopoietic cells. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1101-1101
Author(s):  
Mohammad Sohrab Hossain ◽  
Ghada M Kunter ◽  
Vicky Fayez Najjar ◽  
David L. Jaye ◽  
Edmund K. Waller

Abstract Donor T-lymphocytes are effective adoptive immunotherapy in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT), but life threatening complications related to GVHD limits its clinical application. Recent advancement in the field of immunotherapy has directed our interest to enhancing the anti-tumor response of donor T cells by modulating expression of checkpoint blockade molecules including programmed death-1 (PD-1), cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) and foxp3, the transcription factor associated with regulatory T cells. The two ligands of PD-1, PD-L1 or PD-L2 are highly expressed in the presence of inflammatory signal induced by infection or cancer and PD-1/PD-L1 interaction negatively regulates T-cell antigen receptor (TCR) signaling and dampen T cell cytotoxic activity. Herein, we studied the role of PD-1, CTLA-4 and transcription factor foxp3 expressing donor CD4+ and CD8+ T cells in the development of GVHD. Methods: We have used two established allo-HSCT murine GvHD models. Lethally irradiated wild type (WT) B6, PD-L1 knock out (KO) B6 and PD-L2 KO B6 mice were transplanted with 2 x 106 splenic T cells and 2 x 106 T cell depleted bone marrow (TCD BM) cells from H-2Kdonors. Lethally irradiated CB6F1 recipients were similarly transplanted with splenocytes and TCD BM cells from B6 donors. Acute GvHD scores were determined by combining scores obtained from histological tissue sections and weight-loss, posture, activity, fur texture and skin integrity following standard published procedures. The activation status of donor T-cells and BM and host-derived non-T cells in GvHD target organs was analyzed by flow cytometry. Data from allo-HSCT recipients were compared with the respective data obtained from B6 à B6 syngenic HSCT (syn-HSCT) recipients. Serum cytokines were determined by Luminex assay. Results: PD-L1 KO B6 allo-HSCT recipients had significantly increased acute GvHD scores compared with WT B6 allo-HSCT recipients (p<0.0005) and B6 PD-L2 KO allo-HSCT recipients (p<0.0005) measured on day 8 after transplant. All PD-L1 KO allo-HSCT recipients died within 10 days post transplant while WT B6 and PD-L2 KO allo-HSCT recipients had 20% mortality until 36 days post transplant. Increased acute GvHD was associated with increased amount of serum inflammatory cytokines and increased numbers of activated PD-1+CD69+CD4+ donor T cells. Interestingly, PD-1 expression on donor CD4+ T cells significantly increased in the spleen of transplant recipients but not in BM, while PD-1 expression was significantly increased on donor CD8+ T cells in both spleen and BM compartments of allo-HSCT recipients compared with the syn-HSCT recipients. CTLA-4 expression on CD4+ and CD8+ donor T cells were significantly increased in spleen in the first two weeks post transplant but decreased at later time points compared with syn-HSCT. Again, CTLA-4 expression on CD4+ donor T cells in the BM remained significantly higher measured on 100+ days post transplant in allo-HSCT recipients compared with the syn-HSCT but similar levels of CTLA-4 expression on CD8+ T cells were measured in BM between these two HSCT recipients. Foxp3 expression on donor T cells and the numbers of CD4+CD25+foxp3+ regulatory T (Tregs) were markedly suppressed in donor T cells on day 4 post HSCT of allo-HSCT recipients compared with the syn-HSCT recipients. Although total numbers of donor T cells in the spleen of allo-HSCT recipients remained low over time, the percentage of PD-L1-expressing donor T cells in spleen were significantly higher (p<0.005) at early time points (day 4) in allo-HSCT recipients compared with the syn-HSCT. While total numbers of host-derived cells in spleen decreased over time in mice that developed GvHD, host-derived PD-L1 expressing CD3+ T cells persisted at higher levels through day 36 post transplant. Additionally, PD-L1 expression was also increased in donor BM-derived T cells and non-T cells populations over time. Collectively, these data indicate that severe GvHD occurs in allo-HSCT recipients in spite of increased numbers of PD-1, CTLA-4 and PD-L1 expressing donor and host cells. The occurrence of severe GvHD in these allo-HSCT models systems was associated with markedly reduced levels of CTLA-4 and foxp3 transcription factor expressing Tregs indicating that these pathways may be more relevant to controlling GvHD than PD-1:PD-L1 expression. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2000 ◽  
Vol 96 (2) ◽  
pp. 754-762 ◽  
Author(s):  
Crystal L. Mackall ◽  
Dagmar Stein ◽  
Thomas A. Fleisher ◽  
Margaret R. Brown ◽  
Frances T. Hakim ◽  
...  

Administration of mobilized peripheral blood progenitor cells (PBPCs) after high-dose chemotherapy rapidly restores multilineage hematopoiesis, but the ability of such products to restore lymphocyte populations remains unclear. In this report, we evaluated immune reconstitution in a series of patients treated with sequential cycles of high-dose chemotherapy, followed by autologous PBPC infusions (median CD34+ cell dose 7.2 × 106 cells/kg [range 2-29.3]). Although patients experienced rapid reconstitution of B cells and CD8+ T cells, we observed CD4 depletion and diminished immune responsiveness in all patients for several months after completion of therapy. Mature CD4+ T cells contained within the grafts did not appear to contribute substantially to immune reconstitution because CD4 counts did not differ between recipients of unmanipulated T-cell replete infusions versus CD34 selected, T-cell–depleted infusions. Rather, at 12 months after therapy, total CD4 count was inversely proportional to age (ρ = −0.78,P = .04), but showed no relationship to CD34 cell dose (ρ = −0.42, P = .26), suggesting that age-related changes within the host are largely responsible for the limited immune reconstitution observed. These results demonstrate that in the autologous setting, the infusion of large numbers of PBPCs is not sufficient to restore T-cell immune competence and emphasize that specific approaches to enhance immune reconstitution are necessary if immune-based therapy is to be used to eradicate minimal residual disease after autologous PBPC transplantation.


Blood ◽  
2004 ◽  
Vol 103 (11) ◽  
pp. 4344-4352 ◽  
Author(s):  
Benny J. Chen ◽  
Xiuyu Cui ◽  
Gregory D. Sempowski ◽  
Jos Domen ◽  
Nelson J. Chao

Abstract In the current study, we tested whether higher numbers of hematopoietic stem cells correlate with the speed of immune reconstitution in a congenic transplantation model (C57BL/Ka, CD45.1, Thy1.1→C57BL/6, CD45.2, Thy1.2) using purified hematopoietic stem cells (c-Kit+Thy1.1lowLin-/lowSca-1+). There were 3 different doses of stem cells used (400, 1000, and 5000). Phenotypic analyses in peripheral blood and spleen demonstrated that higher numbers of infused stem cells are associated with more rapid regeneration of T cells (CD4+, CD8+, naive CD4+, naive CD8+) and B cells at early time points. The numbers of T and B cells eventually became equivalent between different dose groups at late time points. Production of interleukin-2 and inter-feron-γ per T cell was similar regardless of stem cell dose even when tested at the time when there were significant differences in peripheral T-cell counts. The improved immune recovery was attributed to a more rapid regeneration of donor-type immune cells. Higher numbers of total thymocytes and signal joint T-cell receptor excision circles were observed in the higher dose stem cell recipients, suggesting that accelerated regeneration of T cells was due to enhanced thymopoiesis. (Blood. 2004;103:4344-4352)


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