scholarly journals Damage to Thymic Stroma Results in Increased Production of Pathogenic Dual Receptor T Cells Associated with Chronic Graft Versus Host Disease

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1156-1156
Author(s):  
Amritha Balakrishnan ◽  
Burhan Jama ◽  
Nicholas Joseph Gloude ◽  
Eric Jon Anderson ◽  
Edward D. Ball ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Graft Versus Host Disease ◽  
Graft Versus Host ◽  
Post Transplant ◽  
Thymic Stroma

Abstract Evidence from clinical investigations and animal models indicate that chronic graft versus host disease (cGVHD) results from defective thymic generation of functional and self-tolerant T cell populations following hematopoietic stem cell transplantation (HSCT). We have previously demonstrated that the rare subset of T cells that naturally express 2 T cell receptors (TCRs) on the cell surface as a result of incomplete allelic exclusion are predisposed to respond to auto- and alloantigens. Dual TCR T cells disproportionately participate in pathologic alloreactivity in HSCT patients and mouse models of acute GVHD. These findings, combined with observations demonstrating that dual TCR T cells represent a physiologic reservoir of unique TCRs that evade negative selection, prompted us to examine the role of thymic selection and dual TCR T cells in cGVHD. To study the role of post-transplant thymopoiesis in generation of potentially pathogenic dual TCR T cells, we used a mouse model of syngeneic bone marrow transplantation into lethally-irradiated recipients. Radiation-induced damage to the thymic stroma was characterized by disruption of thymic architecture and loss of cortical and medullary thymic epithelial cells (TECs). This damage resulted in significantly increased generation of dual TCR T cells following transplantation of congenically-marked syngeneic T cell-depleted bone marrow. Two-fold increased production of dual TCR T cells persisted for at least 20 weeks after transplantation. These data demonstrate the hazard for production of T cells predisposed to pathogenic reactivity in the post-transplant environment, and suggest that dual TCR T cells could be a source of T cells causing cGVHD. To examine involvement of dual TCR T cells in cGVHD, we analyzed peripheral blood samples from patients after allogeneic HSCT (> 12 months post-transplant) using our previously utilized pair-wise TCRVa labeling flow cytometry approach. Flow cytometry analysis revealed that dual TCR T cells were present at increased frequencies in patients with cGVHD (n = 10, 8.3% + 1.1%, P = 0.028) compared to patients without cGVHD (n = 3, 2.5 + 1.1%) or healthy age-matched controls (n = 5, 1.9 + 0.4%). Dual TCR T cells from patients with cGVHD had an activated CD69+ phenotype as compared to T cells expressing only a single TCR from the same patient. Single-cell TCRa/TCRb sequencing confirmed the increased frequencies of dual TCR T cells specific to activated T cells in patients with cGVHD. Repertoire analysis of TCRs sequenced from single cells indicated that the increase in dual TCR T cells was polyclonal. The single-cell sequencing approach enabled multiplexed examination of T cell lineage-associated transcription factors and cytokines. Single-cell transcriptional profiling demonstrated that dual TCR T cells demonstrated predominantly pro-inflammatory and cytotoxic phenotypes with expression of Tbet and perforin. This is in contrast to T cells expressing only a single TCR from the same patient, or dual TCR T cells from healthy control patients, which had a quiescent phenotype. These data indicate a role for dual TCR T cells in mediating cGVHD. Together, these results suggest that dual TCR T cells may be an important link between post-transplant T cell development and cGVHD. Disclosures No relevant conflicts of interest to declare.

PD-L1 and PD-L2 Protect The Heart In a T-Cell Receptor Transgenic Model Of Graft-Versus Host Disease

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4479-4479
Author(s):  
Kathryn W Juchem ◽  
Britt Anderson ◽  
Cuiling Zhang ◽  
Arlene Sharpe ◽  
Jennifer McNiff ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Weight Loss ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Graft Versus Host Disease ◽  
Cell Receptor ◽  
Graft Versus Host ◽  
Post Transplant ◽  
Donor Bone Marrow

Graft-versus-host disease (GVHD) is a complication of allogeneic stem cell transplantation (alloSCT). In murine models of alloSCT, naive T cells (TN) cause GVHD while effector memory T cells (TEM) do not. To determine why TEM fail to cause GVHD, we generated a novel T-cell receptor transgenic GVHD model. In this model CD4+ TS1 T cells, which recognize an epitope of influenza hemagglutinin (HA), are transferred, along with syngeneic bone marrow, into irradiated transgenic recipients that express HA in all tissues (HA104 Tg mice). We found that TS1 TN induced early and prolonged weight loss and caused GVHD-like pathology in the skin, liver and colon. In contrast, TS1 TEM induced mild, transient weight loss and minimal pathology, demonstrating that TEM have repertoire-independent characteristics that limit their ability to induce GVHD. Post transplant analysis revealed that TS1 TEM progeny, relative to TS1 TN progeny, produced less IFN-γ, proliferated and accumulated less in the colon, and expressed higher levels of the inhibitory molecule PD-1. To investigate whether PD-1 was responsible for limiting pathogenesis by TEM, we used hosts and donor bone marrow lacking both PD-L1 and PD-L2. The absence of PD-L1/2 did not enable TS1 TEM to cause early weight loss. However, between 35 and 60 days post transplant, TS1 TEM recipients lacking PD-L1/2 rapidly began losing weight and approximately 50% died. Weight loss in TEM recipients was dependent upon lack of PD-L1/2 expression on both donor bone marrow and host cells, including radioresistant stromal cells, suggesting a possible role for PD-L1/2 expressed in tissues. Indeed, global absence of PD-L1 alone, which (in contrast to PD-L2) is expressed on parenchymal tissues, also resulted in late weight loss in recipients given TEM. To determine the reason for late weight loss, we surveyed tissue histopathology. Surprisingly, in the absence of PD-L1/2, TEM recipients did not develop exacerbated colon pathology but instead developed mononuclear infiltrates and mycocyte necrosis in the heart, accompanied by heart block and decreased cardiac output. Interestingly, heart disease was also seen in PD-L1/2 deficient TN recipients that survived to later time points, indicating that the protective role of PD-L1/2 applied more generally to GVHD induced by CD4 T cells. Strikingly, the extensive infiltrates in affected hearts were mostly comprised of non-TS1 T cells, including both CD4 and CD8 cells. These cells are likely host-derived, as severe cardiac infiltrates were seen when Rag-deficient donor BM was used to reconstitute host hematopoiesis. We therefore hypothesize that in GVHD PD-L1/2 normally prevent “allogeneic” T cell mediated damage but also protect from subsequent syngeneic T cell-mediated pathogenesis that could contribute to prolonged disease. This effect is tissue specific and could in part be due to parenchymal expression of PD-L1 in certain organs. It is possible that such mechanisms could explain more chronic phases of GVHD, which differs from acute GVHD. Ongoing depletion experiments will determine the relative contributions of donor TS1 T cells, donor bone marrow derived T cells and host T cells. Disclosures: No relevant conflicts of interest to declare.

Donor T cell–derived TNF is required for graft-versus-host disease and graft-versus-tumor activity after bone marrow transplantation

Blood ◽  
2003 ◽  
Vol 101 (6) ◽  
pp. 2440-2445 ◽  
Author(s):  
Cornelius Schmaltz ◽  
Onder Alpdogan ◽  
Stephanie J. Muriglan ◽  
Barry J. Kappel ◽  
Jimmy A. Rotolo ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Bone Marrow Transplantation ◽  
T Cell ◽  
Graft Versus Host Disease ◽  
Marrow Transplantation ◽  
F1 Hybrid ◽  
Host Disease ◽  
Graft Versus Host

Previous studies in murine bone marrow transplantation (BMT) models using neutralizing anti-tumor necrosis factor (TNF) antibodies or TNF receptor (TNFR)–deficient recipients have demonstrated that TNF can be involved in both graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL). TNF in these GVHD and GVL models was thought to be primarily produced by activated monocytes and macrophages, and the role of T cell–derived TNF was not determined. We used TNF−/− mice to study the specific role of TNF produced by donor T cells in a well-established parent-into-F1 hybrid model (C57BL/6J→C3FeB6F1/J). Recipients of TNF−/− T cells developed significantly less morbidity and mortality from GVHD than recipients of wild-type (wt) T cells. Histology of GVHD target organs revealed significantly less damage in thymus, small bowel, and large bowel, but not in liver or skin tissues from recipients of TNF−/− T cells. Recipients of TNF−/−T cells which were also inoculated with leukemia cells at the time of BMT showed increased mortality from leukemia when compared with recipients of wt cells. We found that TNF−/− T cells do not have intrinsic defects in vitro or in vivo in proliferation, IFN-γ production, or alloactivation. We could not detect TNF in the serum of our transplant recipients, suggesting that T cells contribute to GVHD and GVL via membrane-bound or locally released TNF.

scholarly journals Prevention of Graft-Versus-Host Disease in Mice Using a Suicide Gene Expressed in T Lymphocytes

Blood ◽  
1997 ◽  
Vol 89 (12) ◽  
pp. 4636-4645 ◽  
Author(s):  
José L. Cohen ◽  
Olivier Boyer ◽  
Benoı̂t Salomon ◽  
Rosine Onclercq ◽  
Frédéric Charlotte ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Graft Versus Host Disease ◽  
Therapeutic Strategy ◽  
Suicide Gene ◽  
Graft Versus Host ◽  
Alloreactive T Cells ◽  
Cell Pool ◽  
Ganciclovir Treatment

Abstract Alloreactive T cells present in a bone marrow transplant are responsible for graft-versus-host disease (GVHD), but their depletion is associated with impaired engraftment, immunosuppression, and loss of the graft-versus-leukemia effect. We developed a therapeutic strategy against GVHD based on the selective destruction of these alloreactive T cells, while preserving a competent T-cell pool of donor origin. We generated transgenic mice expressing in their T lymphocytes the Herpes simplex type 1 thymidine kinase (TK) suicide gene that allows the destruction of dividing T cells by a ganciclovir treatment. T cells expressing the TK transgene were used to generate GVHD in irradiated bone marrow grafted mice. We show that a short 7-day ganciclovir treatment, initiated at the time of bone marrow transplantation, efficiently prevented GVHD in mice receiving TK-expressing T cells. These mice were healthy and had a normal survival. They maintained a T-cell pool of donor origin that responded normally to in vitro stimulation with mitogens or third party alloantigens, but were tolerant to recipient alloantigens. Our experimental system provides the proof of concept for a therapeutic strategy of GVHD prevention using genetically engineered 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.

The Equilibration of Peripheral Blood and Tissue CD3+ T Cell Engraftment Is Influenced by Graft Versus Host Disease Following Reduced Intensity Conditioning Stem Cell Transplantation

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2546-2546
Author(s):  
Victoria Harries ◽  
Rachel Dickinson ◽  
Venetia Bigley ◽  
Matthew Collin
Keyword(s):  
T Cells ◽  
T Cell ◽  
Graft Versus Host Disease ◽  
Peripheral Blood ◽  
Graft Versus Host ◽  
Post Transplant ◽  
Cell Engraftment ◽  
Donor T Cells ◽  
Patients At Risk ◽  
Reduced Intensity

Abstract Abstract 2546 Alemtuzumab-containing reduced intensity transplantation regimens frequently induce a state of partial T cell chimerism in the blood of the recipient. It has been widely shown that partial T cell chimerism is associated with freedom from graft versus host disease (GVHD) and that the occurrence of GVHD is often associated with rapidly rising donor T cell engraftment. The mechanism by which this occurs remains unknown and recipient cells may be killed, out-competed for homeostatic niches or simply diluted out by expanding donor T cells. The skin, a target organ of GVHD, normally contains T cells which enter from the blood in the steady state. Studies in mice have highlighted the gate-keeping function of inflammation in allowing trafficking of host-reactive donor T cells into tissues during conversion from mixed to full donor chimerism in blood. This implies that the equilibration of donor engraftment in the blood and tissue may occur more rapidly in patients at risk for GVHD. To test this hypothesis, we set out to define the relationship between skin and blood donor T cell engraftment in patients with and without GVHD. Methods: We studied a group of 51 patients receiving fludarabine melphalan (FM) conditioning with alemtuzumab 30mg for matched related donors and 60mg for matched unrelated donors. Skin biopsies were obtained at 28 and 100 days post transplant, dermal T cells isolated by migration and chimerism assessed in sex-mismatched transplants by combined immunofluorescence/in situ hybidization for XY chromosomes. Peripheral blood myeloid (CD15+) and T cell (CD3+) chimerism was determined by short tandem repeat amplification at monthly intervals after transplantation. All patients gave consent for clinical follow up and post transplant blood and skin sampling for research purposes, according to protocols approved by the local research ethics committee of Northumberland and North Tyneside. Results: All patients achieved >95% myeloid engraftment by day 100. Median (range) T cell engraftment was variable and significantly higher after MUD transplants: 70% (9-99%) than MRD transplants: 21% (5-85%; Mann Witney p <0.05). The incidence of acute GVHD was also greater after MUD transplantation at 47% (grade I or II) compared with 11% (grade I only) for MRD recipients. Overall a positive correlation was observed between donor T cell engraftment in skin and blood at all time points (r = 0.5792; P 0.0187) and at 100 days (r = 0.6570; P 0.0281). Analysis of the data with respect to GVHD showed a further interesting finding. Patients who developed GVHD had the closest correlation between blood and skin donor engraftment, even when they were in a state of partial T cell chimerism prior to the onset of GVHD. Patients who did not develop GVHD but nonetheless eventually achieved full donor engraftment in the blood tended to show lower levels of donor T cell engraftment in the dermis at day 100. Individual examples of patients who did not develop GVHD are: blood 77%, dermis 37%; blood 77%, dermis 6%; blood 92%, dermis 25%, compared with patients who did develop GVHD: blood 55%, dermis 56%; blood 90%, dermis 75%; blood 100%, dermis 100%. Conclusion: This analysis supports the hypothesis that the equilibration of blood and tissue donor T cells is influenced by GVHD and may offer a means to predict patients at risk of GVHD after withdrawal of immunosuppression or donor lymphocyte infusion. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Critical role of host γδ T cells in experimental acute graft-versus-host disease

Blood ◽  
2005 ◽  
Vol 106 (2) ◽  
pp. 749-755 ◽  
Author(s):  
Yoshinobu Maeda ◽  
Pavan Reddy ◽  
Kathleen P. Lowler ◽  
Chen Liu ◽  
Dennis Keith Bishop ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Graft Versus Host Disease ◽  
Critical Role ◽  
Γδ T Cells ◽  
Allogeneic Bone ◽  
Host Disease ◽  
Graft Versus Host ◽  
Tnf Α

Abstract γδ T cells localize to target tissues of graft-versus-host disease (GVHD) and therefore we investigated the role of host γδ T cells in the pathogenesis of acute GVHD in several well-characterized allogeneic bone marrow transplantation (BMT) models. Depletion of host γδ T cells in wild-type (wt) B6 recipients by administration of anti-T-cell receptor (TCR) γδ monoclonal antibody reduced GVHD, and γδ T-cell-deficient (γδ-/-) BM transplant recipients experienced markedly improved survival compared with normal controls (63% vs 10%, P &lt; .001). γδ T cells were responsible for this difference because reconstitution of γδ-/- recipients with γδ T cells restored GVHD mortality. γδ-/- recipients showed decreased serum levels of tumor necrosis factor α (TNF-α), less GVHD histopathologic damage, and reduced donor T-cell expansion. Mechanistic analysis of this phenomenon demonstrated that dendritic cells (DCs) from γδ-/- recipients exhibited less allostimulatory capacity compared to wt DCs after irradiation. Normal DCs derived from BM caused greater allogeneic T-cell proliferation when cocultured with γδ T cells than DCs cocultured with medium alone. This enhancement did not depend on interferon γ (IFN-γ), TNF-α, or CD40 ligand but did depend on cell-to-cell contact. These data demonstrated that the host γδ T cells exacerbate GVHD by enhancing the allostimulatory capacity of host antigen-presenting cells. (Blood. 2005;106:749-755)

scholarly journals Patient Bone Marrow Chimerism at Time of Donor Lymphocyte Infusion Predicts Development of Graft Versus Host Disease

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2132-2132
Author(s):  
Eva AS Koster ◽  
Liesbeth C. de Wreede ◽  
Sylwia Wallet-Malicka ◽  
Lisette Bogers ◽  
Peter van Balen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Graft Versus Host Disease ◽  
Hazard Ratio ◽  
The State ◽  
Host Disease ◽  
Graft Versus Host ◽  
Donor T Cells ◽  
Donor Type

Abstract After allogeneic stem cell transplantation (alloSCT), donor T cells targeting patient derived hematopoietic cells can induce a Graft versus Leukemia (GvL) effect preventing relapse. However, targeting of healthy patient tissues can cause Graft versus Host Disease (GvHD). The inflammatory environment induced by pre transplantation conditioning, the number of donor T cells in the graft, genetic disparity between patient and donor and the presentation of allo-antigens by activated patient derived antigen-presenting cells (APC) to donor T cells play a role in the development of GvL and/or GvHD. Donor T cell depletion (TCD) reduces GvHD and GvL. After TCD alloSCT, postponed prophylactic donor lymphocyte infusions (pDLI) are often needed to induce a GvL effect. When using 10/10 matched donors, our first dose of pDLI at six months after TCD alloSCT contained 3.0x10^6 T cells/kg (related donor, RD) or 1.5x10^6 T cells/kg (unrelated donor, UD). We evaluated whether the risk of developing GvHD after DLI is influenced by the donor type, intensity of the conditioning and/or patient bone marrow (BM) chimerism at time of DLI Sixty patients with acute leukemia (52 AML, 8 ALL; median age 57; 27 RD, 33 UD) received pDLI at a median of 6.4 months after TCD alloSCT in the absence of GVHD or relapse. Twenty-four patients received myeloablative (MA) conditioning consisting of cyclophosphamide and TBI. 36 patients received non-myeloablative (NMA) conditioning based on fludarabin and busulphan. TCD was performed by adding 20mg alemtuzumab to the graft. Only MA conditioned patients with an UD (n=12) received post transplantation ciclosporin as GvHD prophylaxis, which was tapered from 1 month after alloSCT. Clinically significant GvHD was defined as need of therapeutic systemic immunosuppression (tIS) for GvHD for at least 2 weeks or until death. Bone Marrow (BM) chimerism was measured prior to DLI. Three categories of patient chimerism levels were defined: no patient derived cells (absent), patient derived cells present, but < 5% (low), or ≥ 5% (high). In case of persisting or increasing patient chimerim after pDLI, a second DLI was given at 3-6 months after the first. A multi-state model was designed (Figure 1) with the first DLI (DLI1) as starting state and time. Patients starting tIS after DLI1 transit to the state tIS. Patients who need a second DLI, develop a relapse or die, transit to these respective states. Patients who stay in the state of DLI1 are considered to have a positive outcome. All patients had a follow-up of at least one year after DLI. Numbers in the boxes in Figure 1 represent the number of patients in that state at 1 year after DLI1 and numbers next to the arrows indicate the numbers of patients who made the transition between the two states. Donor type (unrelated versus related), conditioning (NMA versus MA) and patient BM chimerism at time of DLI were included in a Cox model for the transition hazards to investigate their association with the development of GvHD after DLI. For the total group, the cumulative incidence of tIS at 1 year after pDLI was 33% (95% CI 21-45%). Patients with an UD had a hazard ratio (HR) of 1.1 (95% CI 0.4-3.3) of needing tIS after DLI1 compared to patients with a RD. Compared to MA conditioning, NMA conditioned patients had a hazard ratio of 2.1 (95% CI 0.5-8.9) of needing tIS after DLI. They had a HR of 0.2 (95% CI 0.04-0.95) of stopping tIS compared to MA conditioned patients, indicating that DLI after NMA conditioning is associated with more severe GVHD. We hypothesized that this was due to the persistence of patient derived APC. BM chimerism at time of DLI was measured in 47 patients. After NMA and MA conditioning, BM patient chimerism was absent in 14% and 56%, low in 41% and 39%, and high in 45% and 6%, respectively (Fisher's exact test p=0.002 for difference between type of conditioning). Compared to the group without patient chimerism, the low and high patient chimerism group had a HR of 1.9 (95% CI 0.9-4.2) and 3.6 (95% CI 1.7-8.0) of needing tIS after DLI, respectively (Figure 2), demonstrating that the level of patient chimerism is a strong predictor for development of GvHD after DLI, even when taking into account the type of conditioning regimen. Patient BM chimerism at time of pDLI is a strong and independent predictor for the risk of developing GvHD. Dose reduction in case of an UD equalized the GvHD risk compared to a RD. When choosing a T cell dose for pDLI, patient chimerism should be considered a relevant parameter. Disclosures No relevant conflicts of interest to declare.

scholarly journals Tissue Derived Non-Classical Monocyte Derived Host Macrophages Protect Against Murine Intestinal Acute Graft-Versus-Host Disease

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3315-3315
Author(s):  
Duc Dung Le ◽  
Ana-Laura Jordán Garrote ◽  
Ranecky Maria ◽  
Katja J Ottmüller ◽  
Haroon Shaikh ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Lamina Propria ◽  
Graft Versus Host Disease ◽  
Intestinal Tract ◽  
Graft Versus Host ◽  
Cell Responses ◽  
Alloreactive T Cell ◽  
Acute Graft

Abstract Acute graft versus host disease (aGVHD) remains a major complication in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT), the only curative treatment for many malignant hematologic diseases. After initial priming in secondary lymphoid organs, alloreactive donor T cells efficiently migrate to the intestinal tract, liver and skin. We observed that alloreactive effector T cells infiltrating and attacking the lamina propria of the small and large intestines closely interact with intestinal myeloid cells of host origin. Here we asked whether these intimate interactions regulate alloreactive effector T cell responses and how they impact intestinal aGvHD. To address these questions, we employed non-invasive bioluminescence imaging, fluorescence and confocal microscopy, clinical and histopathologic scoring, flow cytometry and single cell RNA sequencing in murine models of myeloablative, MHC-mismatched allo-HSCT. In the intestinal lamina propria, we observed that allogeneic T cells closely interacted with CD11b+CD11c+CD103- radio-resistant host type hematopoietic myeloid antigen presenting cells. Selective depletion of intestinal CD11chi or CX3CR1+CD11chi host cells 3 or 8 days after allo-HSCT accelerated alloreactive T cell infiltration, increased T cell mediated inflammatory cytokine production and exacerbated tissue damage resulting in hyperacute lethal aGvHD. These results suggested a strong immunoregulatory effect of these intestinal host-type myeloid cells. Single cell RNA-Seq analysis and flow cytometry (e.g. MHC II, CD11c, F4/80, CD26, CD64, CCR2, CX3CR1), lineage reporter- and defined knockout mice determined these cells as non-classical monocyte derived macrophages as the development and differentiation of these cells did not depend on Flt3, Zbtb46, and CCR2 but rather on CSF-1R and CX3CR1. Adoptive transfer, bone marrow chimeras and parabiosis experiments revealed that these non-classical monocyte derived macrophages differentiated from non-circulating non-classical monocytic precursors. Finally, PD-L1 expression on these intestinal host non-classical monocyte derived macrophages but not on stroma or other hematopoietic cells regulated alloreactive T cell responses in the intestinal tract. Based on these findings we postulate that a specialized and persistent subpopulation of host non-classical monocyte derived macrophages can potently suppress alloreactive T cells in the lamina propria of the intestinal tract. Fostering the differentiation and function of these tissue resident cells may represent an attractive therapeutic strategy to prevent intestinal aGvHD. Disclosures No relevant conflicts of interest to declare.

scholarly journals Impact of pretransplant conditioning and donor T cells on chimerism, graft-versus-host disease, graft-versus-leukemia reactivity, and tolerance after bone marrow transplantation

Blood ◽  
1991 ◽  
Vol 77 (11) ◽  
pp. 2515-2523
Author(s):  
RL Truitt ◽  
AA Atasoylu
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Bone Marrow Transplantation ◽  
T Cell ◽  
Graft Versus Host Disease ◽  
Mixed Chimerism ◽  
Cell Content ◽  
Graft Versus Host ◽  
Graft Versus Leukemia ◽  
Donor T Cells

Graft rejection, mixed chimerism, graft-versus-host disease (GVHD), leukemia relapse, and tolerance are interrelated manifestations of immunologic reactivity between donor and host cells that significantly affect survival after allogeneic bone marrow transplantation (BMT). In this report, a mouse model of BMT, in which the donor and host were compatible at the major histocompatibility complex (MHC), was used (1) to examine the interrelationship of pretransplant conditioning and T- cell content of donor BM with regard to lymphoid chimerism and GVHD and (2) to determine how these factors affected graft-versus-leukemia (GVL) reactivity and donor-host-tolerance. AKR (H-2k) host mice were administered optimal or suboptimal total body irradiation (TBI) as pretransplant conditioning followed by administration of BM cells from B10.BR (H-2k) donor mice with or without added spleen cells as a source of T lymphocytes. Transplanted mice were injected with a supralethal dose of AKR leukemia cells 20 and 45 days post-BMT to assess GVL reactivity in vivo. The pretransplant conditioning of the host and T- cell content of the donor marrow affected the extent of donor T-cell chimerism and the severity of GVH disease. GVL reactivity was dependent on transplantation of mature donor T cells and occurred only in complete chimeras. Transplantation of T-cell-deficient BM resulted in the persistence of host T cells, ie, incomplete donor T-cell chimerism, even when lethal TBI was used. Mixed chimerism was associated with a lack of GVL reactivity, despite the fact that similar numbers of donor T cells were present in the spleens of mixed and complete chimeras. In this model, moderate numbers of donor T cells facilitated complete donor T-cell engraftment, caused only mild GVHD, and provided a significant GVL effect without preventing the subsequent development of tolerance after conditioning with suboptimal TBI. In contrast, severe, often lethal, GVHD developed when the dose of TBI was increased, whereas tolerance and no GVH/GVL reactivity developed when the T-cell content of the marrow was decreased.

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