MiR-146a Regulates the TRAF6/TNF-Axis in Donor T Cells during Graft-Versus-Host Disease

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 843-843
Author(s):  
Natalie Stickel ◽  
Gabriele Prinz ◽  
Dietmar Pfeifer ◽  
Annette Schmitt-Graeff ◽  
Marie Follo ◽  
...  
Keyword(s):  
T Cells ◽  
Graft Versus Host Disease ◽  
Acute Gvhd ◽  
Negative Regulator ◽  
Snp Analysis ◽  
Hematopoietic Stem ◽  
Host Disease ◽  
Graft Versus Host ◽  
Donor T Cells

Abstract Introduction: Acute graft-versus-host disease (GvHD) arises from the attack of recipient tissues by donor allogeneic T cells and represents one of the major limitations of allogeneic hematopoietic cell transplantation (allo-HCT). In spite of many clinical trials, the standard immunosuppressive regimens for prevention of acute GvHD have improved little in the last two decades. Hence, a better understanding of the biology of acute GvHD may improve therapeutic options. MicroRNA-146a (miR-146a) was found to be increased in the sera of patients with GvHD. Therefore, we aimed to decipher the role of miR-146a in allogeneic donor T cells during GvHD by functional studies and in patients undergoing allo-HCT by single nucleotide polymorphism (SNP) analysis. Methods: We used two different murine major MHC mismatch models for acute GvHD. Recipient mice were conditioned with irradiation before transplantation of bone marrow and either wildtype or miR-146a deficient T cells from allogeneic donor mice. Furthermore, genomic DNA from 289 patients that underwent allo-HCT and their respective hematopoietic stem cell donors was isolated in order to determine their miR-146a rs2910164genotype. Results: We observed miR-146a upregulation in T cells of mice developing acute GvHD compared to untreated mice in a major MHC and a minor histocompatibility antigen mismatch model. Transfer of miR-146a deficient T cells caused increased GvHD severity, elevated TNF serum levels and reduced survival. Conversely, the phytochemical induction of miR-146a or its overexpression in donor T cells using a specific miR-146a mimic reduced GvHD severity. TNF receptor-associated factor 6 (TRAF6), a verified target of miR-146a, was upregulated in miR-146a-/- T cells following alloantigen stimulation. Higher TRAF6 levels translated into increased NF-κB activity and TNF production in miR-146a-/- T cells, while other pro-inflammatory cytokine levels were unaffected. The detrimental effect of miR-146a deficiency in T cells could be antagonized by TNF blockade in vivo. Moreover, in contrast to WT T cells, over expression of miR-146a in Tnf deficient T cells had no effect on their alloreactivity. In the human system, the minor genotype of the SNP rs2910164, which causes reduced miR-146a expression, was more frequent in patients developing acute GvHD grade III/IV compared to all other allo-HCT recipients (n=289). Conclusions: Taken together we show that miR-146a functions as a negative regulator of the TRAF6/TNF-axis in allogeneic donor T cells during GvHD, leading to reduced TNF transcription. Given our observation on the predictive role of the SNP leading to decreased miR-146a expression in acute GvHD in patients and the possibility to exogenously enhance miR-146a expression, we provide a novel and targeted molecular approach to mitigate GvHD. Disclosures No relevant conflicts of interest to declare.

Graft-Versus-Host-Disease Recruits Both Monocyte and Pre-Conventional Dendritic Cell-Derived Tissue Antigen Presenting Cells Independent Of CCR2 and CCR6

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4463-4463
Author(s):  
Sarah Morin-Zorman ◽  
Christian Wysocki ◽  
Catherine Matte-Martone ◽  
Kathryn W Juchem ◽  
Hung Sheng Tan ◽  
...  
Keyword(s):  
T Cells ◽  
Graft Versus Host Disease ◽  
Antigen Presenting Cells ◽  
Blood Monocytes ◽  
Hematopoietic Stem ◽  
Host Disease ◽  
Graft Versus Host ◽  
Donor T Cells ◽  
Antigen Presenting

Graft-versus-host disease (GVHD) limits the broader application of allogeneic hematopoietic stem cell transplantation. In prior studies we defined roles for both host and donor-derived antigen presenting cells (APCs) in the activation of alloreactive donor T cells and in promotion of GVHD. While initial T cell activation in GVHD occurs predominantly in secondary lymphoid organs, we have consistently observed MHCII+ donor-derived APCs, including dendritic cells (DCs), in histopathologic GVHD lesions, frequently adjacent to infiltrating T cells, suggesting they have a role in local GVHD reactions. Donor-derived tissue APCs (t-APCs), including tissue-DCs (t-DCs) could activate donor T cells through indirect or cross-presentation of host antigens, produce chemokines that recruit other effectors, and elaborate inflammatory mediators or suppressors of inflammation. We first characterized t-DC subsets in the skin and bowel of GVHD-affected mice. 129 (H-2b) hosts were irradiated and reconstituted with B6 (H-2b) BM with or without CD4+ and CD8+ T cells to induce GVHD and analyzed mononuclear cells from skin and bowel approximately 4 weeks post transplant. In skin, both main dermal DC populations (CD11b+ and CD103+) were significantly increased in GVHD mice as compared to BM alone controls, though the ratios of CD11b+: CD103+ DCs were similar. In the bowel lamina propria, the ratios of CD11b+CD103- to CD11b+CD103+ were increased in GVHD mice in the colon but were similar to that in BM alone controls in the small bowel. We next studied the roles of CCR6 and CCR2 in the recruitment of donor-derived APCs to skin and bowel. We transplanted mice with CCR6-/- BM in competition with wild type (wt) BM and found that the contribution of each to skin and bowel APCs matched their contributions to myeloid hematopoiesis in BM, spleen and blood, indicating that CCR6 is not required. To study the role of CCR2 we first compared mice transplanted with either wt or CCR2-/- BM with wt T cells. Despite having a profound reduction in blood monocytes, all skin and bowel t-APC subsets were present in CCR2-/- recipients, indicating that CCR2 is not required for t-APC recruitment in contrast to its role in many other models of inflammation. However, CD103+ DCs were more prevalent relative to CD11b+ DCs, consistent with a pre-cDC origin. Despite monocytopenia, recipients of CCR2-/- BM developed clinical GVHD; histology data is being analyzed and will be presented. To better define the contributions of CCR2 to t-APC recruitment and to determine monocyte versus pre-cDC origin of t-DCs, we transplanted mice with CCR2-/- BM in competition with wt BM and compared ratios of BM and blood precursors (pre-cDCs and monocytes) to t-DC ratios. For CD103+ DCs, wt/KO ratios matched the ratios of general myeloid hematopoiesis and pre-cDCs, indicating a pre-cDC origin. For CD11b+CD103- DCs, the ratio of wt/KO matched that in blood monocytes. We further subsetted CD11b+ t-DCs based on the expression of Ly6C, MAR1, CD64 and CD24, used to differentiate pre-cDC from mono-derived DCs in other organs, and did not identify any population with wt/KO ratios that did not match that of the general CD11b+ DC population, suggesting that most if not all CD11b+ t-DCs are of monocyte origin. Experiments are underway examining the role of CX3CR1 in t-APC recruitment and these data will be presented. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The role of antigen-presenting cells in triggering graft-versus-host disease and graft-versus-leukemia

Blood ◽  
2007 ◽  
Vol 110 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Ronjon Chakraverty ◽  
Megan Sykes
Keyword(s):  
Graft Versus Host Disease ◽  
Acute Gvhd ◽  
Tissue Injury ◽  
Chronic Gvhd ◽  
Host Disease ◽  
Graft Versus Host ◽  
Graft Versus Leukemia ◽  
Donor T Cells ◽  
Antigen Presenting

After allogeneic blood or bone marrow transplantation, donor T cells interact with a distorted antigen-presenting cell (APC) environment in which some, but not all, host APCs are replaced by APCs from the donor. Significantly, host APCs are required for the priming of acute graft-versus-host disease (GVHD). Donor APCs play a lesser role in the induction of acute GVHD despite their predicted capacity to cross-present host antigens. In contrast, donor APCs may play a role in perpetuating the tissue injury observed in chronic GVHD. Host APCs are also required for maximal graft-versus-leukemia responses. Recent studies have suggested potential strategies by which the continued presence of host APCs can be exploited to prime strong donor immunity to tumors without the induction of GVHD.

Selective Depletion of Alloreacting CD25+ Cells from Stem Cell Allografts Can Reduce Acute Graft-Versus-Host Disease Following Matched Related Donor Transplantation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 426-426
Author(s):  
Scott R. Solomon ◽  
Thao Tran ◽  
Charles S. Carter ◽  
Nancy Hensel ◽  
Laura Wisch ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
Graft Versus Host Disease ◽  
Acute Gvhd ◽  
Cell Transplant ◽  
Host Disease ◽  
Graft Versus Host ◽  
Gvhd Prophylaxis ◽  
Donor T Cells ◽  
Related Donor

Abstract Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic stem cell transplant (SCT), especially in older patients. We previously showed that host-reactive donor T cells are selectively depleted (SD) from an allograft ex vivo, following a short co-culture of donor cells with irradiated T cell stimulators from the recipient and subsequent treatment with an anti-CD25 immunotoxin. We report a pilot study to test the hypothesis that GVHD could be decreased in a cohort of elderly patients receiving SD allografts from HLA-identical sibling donors. Sixteen patients, median age 65 years (range 51–73), with advanced hematologic malignancies were transplanted following reduced-intensity conditioning with fludarabine and either cyclophosphamide (n=5), melphalan (n=5), or busulfan (n=6). Cyclosporine was used as the only additional GVHD prophylaxis. SD allografts contained a median CD34 dose of 4.5x106/kg (range 3.5–7.3) and an SD CD3 dose of 1.0x108/kg (range 0.2–1.5). Fifteen patients achieved sustained engraftment. The helper T lymphocyte precursor (HTLp) frequency assay demonstrated depletion of host-reactive donor T cells in 9/11 cases tested from a mean of 1/182,089 to 1/822,354 (mean 5.5-fold depletion), while third party responses were conserved. Kaplan-Meier estimates of probability of grade II-IV and grade III-IV acute GVHD were lower than those seen in a historical control group of patients receiving cyclosporine alone for GVHD prophylaxis (35±13% vs. 57±10%, p=0.34) and (7±6% vs. 38±6%, p=0.05), respectively. Of note, the two patients who developed visceral (gut ± liver) GVHD showed ineffective allodepletion by HTLp (figure). Chronic GVHD occurred in five of 14 evaluable patients. At a median follow-up of 212 days (range 60 – 690), seven of sixteen patients remain alive and in remission. Relapse deaths occurred in four patients (refractory AML [2], therapy-related MDS [1], and CMML [1]). Non-relapse mortality in this high-risk cohort of patients included graft failure [1], GVHD [2], infection [1], and myocardial infarction [1]. In summary, CD25-directed allodepletion of stem cell allografts can reduce clinically relevant acute GVHD following matched related donor transplantation. Figure Figure

The Role of Selective Depletion of Alloreactive Donor T Cells in Graft-Versus-Host Disease after Allogeneic Bone Marrow Transplantation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5167-5167
Author(s):  
Yihuan Chai ◽  
Huiying Qiu ◽  
Hui Lv
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Graft Versus Host Disease ◽  
Acute Gvhd ◽  
Allogeneic Bone Marrow ◽  
Third Party ◽  
Allogeneic Bone ◽  
Host Disease ◽  
Graft Versus Host ◽  
Donor T Cells

Abstract One of the main goals in allogeneic bone marrow(BM) transplantation is the abrogation of graft-versus-host disease (GVHD) with the preservation of antileukemia and antiviral activity. The Study present a selective T cell depletion strategy based on the physical separation of the alloreactive T cells, which were identified by expression of two activation-induced antigens (CD25 and CD69). T cells from C57BL/6(H-2b) mice were first activated with BALB/c (H-2d) recipient spleen cells in a 2-day mixed-lymphocyte-culture (MLC). Following this activation, this compound is selectively depleted based on expression of two activation-induced antigens CD25 and CD69 using magnetic cell sorting. The depleted cells or the untreated cells were then rechallenged respectively in a secondary MLC, with the same stimulator cells or a third-party (DBAH-2k) or tumor- specific (SP2/0, BALB/c-origin myeloma) cells. Cells proliferation were assayed at the indicated time points(1, 2, 3, 4, 5 days). These treated cells or control-cultured cells (2.0×106) mixed with 5.0×106 BM cells from C57BL/6 were transfused respectively by the trail vain into the lethally irradiated BALB/c to observe the survival time, GVHD incidence and pathological analysis. MLC assays demonstrated that this technique led to a significant decrease in alloreactivity of donor cells(29.02~64.17%), which at the same time preserved reactivity against third party cells(49.61~75.69%)and anti-tumor cells(61.14~68.62%). The mice in the group of control-coclutured were died of acute GVHD within 24days. The 7 recipient mice in the treated group were free of acute GVHD, and 3 mice were died of acute GVHD (aGVHD) within 23 days. MACS-based ex-vivo depletion of alloreactive donor T cells based on expression of two activation-induced antigens (CD25 and CD69) could inhibit anti-host responses, by contrast, anti-SP2/O and anti-third-party responses were preserved. Cotransplantation of these selected depleted cells and BM cells could reduce aGVHD.

scholarly journals Role of CD8 Regulatory T Cells versus Tc1 and Tc17 Cells in the Development of Human Graft-versus-Host Disease

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Adriana Gutiérrez-Hoya ◽  
Rubén López-Santiago ◽  
Jorge Vela-Ojeda ◽  
Laura Montiel-Cervantes ◽  
Octavio Rodríguez-Cortés ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Graft Versus Host Disease ◽  
Treg Cells ◽  
Protective Role ◽  
Hematopoietic Stem ◽  
Host Disease ◽  
Graft Versus Host ◽  
Tc17 Cells

CD8+ T cells that secrete proinflammatory cytokines play a central role in exacerbation of inflammation; however, a new subpopulation of CD8 regulatory T cells has recently been characterized. This study analyzes the prominent role of these different subpopulations in the development of graft-versus-host disease (GVHD). Samples from 8 healthy donors mobilized with Filgrastim® (G-CSF) and 18 patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) were evaluated by flow cytometry. Mobilization induced an increase in Tc1 (p<0.01), Th1 (p<0.001), Tc17 (p<0.05), and CD8+IL-10+ cells (p<0.05), showing that G-CSF induces both pro- and anti-inflammatory profiles. Donor-patient correlation revealed a trend (p=0.06) toward the development of GVHD in patients who receive a high percentage of Tc1 cells. Patients with acute GVHD (aGVHD), either active or controlled, and patients without GVHD were evaluated; patients with active aGVHD had a higher percentage of Tc1 (p<0.01) and Tc17 (p<0.05) cells, as opposed to patients without GVHD in whom a higher percentage of CD8 Treg cells (p<0.01) was found. These findings indicate that the increase in Tc1 and Tc17 cells is associated with GVHD development, while regulatory CD8 T cells might have a protective role in this disease. These tests can be used to monitor and control GVHD.

Nanoparticle-Encapsulated Allogeneic T Cells Mitigate Graft-Versus-Host Disease but Retain Graft-Versus-Leukemia Activity

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3820-3820
Author(s):  
Lingling Zhang ◽  
Shuting Zhao ◽  
Steven M. Devine ◽  
Xiaoming He ◽  
Jianhua Yu
Keyword(s):  
T Cells ◽  
Graft Versus Host Disease ◽  
Conflicts Of Interest ◽  
Hematopoietic Stem ◽  
Host Disease ◽  
Graft Versus Host ◽  
Electrostatic Deposition ◽  
Graft Versus Leukemia ◽  
Donor T Cells

Abstract Allogeneic hematopoietic stem cell transplantation (HSCT) has curative potential for hematological malignancies, but is often associated with life-threatening complications including graft-versus-host disease (GVHD). The graft-versus-leukemia (GVL) activity which accompanies HSCT is responsible for eradication of tumor cells and prevention of relapse. GVHD and GVL are usually associated with each other and the separation of the two activities occurs in limited circumstances. In this study, we aimed to mitigate GVHD but retain GVL through transplantation of allogeneic T cells encapsulated with bio-degradable nanoparticle materials. For the above purpose, donor T cells were encapsulated with chitosan and alginate through layer-by-layer coating using electrostatic deposition. Encapsulated donor T cells were characterized in vitro, and their ability to inhibit GVHD and retain GVL was determined in vivo after being transplanted together with non-encapsulated donor bone marrow (BM) cells in a C57BL/6 → BALB/c HSCT mouse model. We found 85.7% of donor T cells were successfully encapsulated by the above method (Fig 1A). In vitro studies showed that the encapsulation did not change the phenotype of T cells as defined through the following parameters: size, viability, proliferation, antibody binding, cytokine secretion, and cytotoxicity of T cells (Fig. 1B and data not shown). Mice transplanted with encapsulated allogeneic T cells exhibited less severe acute GVHD and prolonged survival (Fig. 1 C-E). The mice showed a lower GVHD score, less liver damage, a smaller CD8/CD4 T cell ratio, and a higher number of donor BM-derived cells following transplantation with encapsulated donor T cells (Fig. 1 C-E and data not shown). When this GVHD model was combined with implantation of A20 lymphoma cells, GVL of encapsulated T cells was not compromised, while GVHD was still suppressed and the mouse survival also prolonged (Figure 2). In summary, nanoencapsulation of T cells with bio-degradable materials attenuated the severity of GVHD but retained GVL, presenting a novel and potentially safer and effective approach of allogeneic HSCT for future clinical application. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

scholarly journals Selective depletion of alloreactive donor lymphocytes: a novel method to reduce the severity of graft-versus-host disease in older patients undergoing matched sibling donor stem cell transplantation

Blood ◽  
2005 ◽  
Vol 106 (3) ◽  
pp. 1123-1129 ◽  
Author(s):  
Scott R. Solomon ◽  
Stephan Mielke ◽  
Bipin N. Savani ◽  
Aldemar Montero ◽  
Laura Wisch ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
Graft Versus Host Disease ◽  
Older Patients ◽  
Acute Gvhd ◽  
Ex Vivo ◽  
Host Disease ◽  
Graft Versus Host ◽  
Cd34 Cells ◽  
Donor T Cells

AbstractWe have selectively depleted host-reactive donor T cells from peripheral blood stem cell (PBSC) transplant allografts ex vivo using an anti-CD25 immunotoxin. We report a clinical trial to decrease graft-versus-host disease (GVHD) in elderly patients receiving selectively depleted PBSC transplants from HLA-identical sibling donors. Sixteen patients (median age, 65 years [range, 51-73 years]), with advanced hematologic malignancies underwent transplantation following reduced-intensity conditioning with fludarabine and either cyclophosphamide (n = 5), melphalan (n = 5), or busulfan (n = 6). Cyclosporine was used as sole GVHD prophylaxis. The allograft contained a median of 4.5 × 106 CD34 cells/kg (range, 3.4-7.3 × 106 CD34 cells/kg) and 1.0 × 108/kg (range, 0.2-1.5 × 108/kg) selectively depleted T cells. Fifteen patients achieved sustained engraftment. The helper T-lymphocyte precursor (HTLp) frequency assay demonstrated successful (mean, 5-fold) depletion of host-reactive donor T cells, with conservation of third-party response in 9 of 11 cases tested. Actuarial rates of acute GVHD were 46% ± 13% for grades II to IV and 12% ± 8% for grades III to IV. These results suggest that allodepletion of donor cells ex vivo is clinically feasible in older patients and may reduce the rate of severe acute GVHD. Further studies with selectively depleted transplants to evaluate graft-versus-leukemia (GVL) and survival are warranted.

scholarly journals Interleukin-18 Regulates Acute Graft-Versus-Host Disease by Enhancing Fas-mediated Donor T Cell Apoptosis

2001 ◽  
Vol 194 (10) ◽  
pp. 1433-1440 ◽  
Author(s):  
Pavan Reddy ◽  
Takanori Teshima ◽  
Mark Kukuruga ◽  
Rainer Ordemann ◽  
Chen Liu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Graft Versus Host Disease ◽  
Acute Gvhd ◽  
Host Disease ◽  
Murine Bone Marrow ◽  
Graft Versus Host ◽  
Donor T Cells ◽  
Ifn Γ ◽  
Acute Graft

Interleukin (IL)-18 is a recently discovered cytokine that modulates both T helper type 1 (Th1) and Th2 responses. IL-18 is elevated during acute graft-versus-host disease (GVHD). We investigated the role of IL-18 in this disorder using a well characterized murine bone marrow transplantation (BMT) model (B6 → B6D2F1). Surprisingly, blockade of IL-18 accelerated acute GVHD-related mortality. In contrast, administration of IL-18 reduced serum tumor necrosis factor (TNF)-α and lipopolysaccharide (LPS) levels, decreased intestinal histopathology, and resulted in significantly improved survival (75 vs. 15%, P &lt; 0.001). Administration of IL-18 attenuated early donor T cell expansion and was associated with increased Fas expression and greater apoptosis of donor T cells. The administration of IL-18 no longer protected BMT recipients from GVHD when Fas deficient (lpr) mice were used as donors. IL-18 also lost its ability to protect against acute GVHD when interferon (IFN)-γ knockout mice were used as donors. Together, these results demonstrate that IL-18 regulates acute GVHD by inducing enhanced Fas-mediated apoptosis of donor T cells early after BMT, and donor IFN-γ is critical for this protective effect.

scholarly journals NOD2 Regulates Hematopoietic Cell Function During Graft-Versus-Host Disease.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2453-2453
Author(s):  
Olaf Penack ◽  
Odette M. Smith ◽  
Nury Yim ◽  
Uttam Rao ◽  
Arnab Ghosh ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Graft Versus Host Disease ◽  
Experimental Colitis ◽  
Hematopoietic System ◽  
Host Disease ◽  
Graft Versus Host ◽  
Donor T Cells ◽  
Group B

Abstract Abstract 2453 Poster Board II-430 NOD2 polymorphisms are independent risk factors for Crohn's disease and graft-versus-host disease (GVHD). In Crohn's disease, the pro-inflammatory state resulting from NOD2 mutations have been associated with a loss of anti-bacterial function of enterocytes, such as paneth cells. NOD2 has not been studied in experimental allogeneic bone marrow transplantation (allo-BMT). We studied the role of NOD2 during inflammation in murine models of graft-versus-host disease (GVHD) and in experimental colitis. To investigate the role of NOD2 in regulating GVHD in allo-BMT recipients, we used MHC-matched as well as MHC-disparate allo-BMT models. We first assessed the role of NOD2 deficiency of the allo-BMT donor (either donor T cells or bone marrow) and found no significant impact on the development of GVHD. In contrast, we observed significantly more lethal GVHD in NOD2-/- allo-BMT recipients as compared with WT allo-BMT recipients. We next created chimeric mice, which were NOD2 deficient either in the hematopoietic or non-hematopoietic system. After three months, we performed allo-BMTs (B10BRþB6 and LPþB6) using either WT, NOD2-/- or chimeric recipients. We found that the NOD2 deficiency in the hematopoietic system of the recipient, as opposed to a NOD2 deficiency in the non-hematopoietic system, is responsible for the increased severity of GVHD (Fig. 1A). In NOD2-/- allo-BMT recipients we observed that the absolute number of donor T cells as well as their activation status was significantly increased. Next, we transferred CFSE labeled allogeneic WT T cells to NOD2-/- allo-BMT recipients and found increased proliferation and activation, suggesting that NOD2 plays a role in the regulation of host antigen presenting cells (APCs). We then quantified the expression of activation markers and co-stimulatory molecules on host dendritic cells (DCs): CD40, CD80 and CD86 were significantly up-regulated of on host NOD2-/- DCs as compared with WT DCs during GVHD. To study DC function we selected splenic DCs from WT and NOD2-/- allo-BMT recipients with GVHD and used them as stimulators in mixed leukocyte reactions (MLRs). NOD2-/- DCs had a significantly increased ability to induce proliferation of allogeneic T cells as compared with WT DCs. Finally, we used bone marrow chimeras in an experimental colitis model (which has not been done before) and observed again that NOD2 deficiency in the hematopoietic cells results in increased intestinal inflammation (Figure 1B). We conclude that NOD2 regulates the development of GVHD through its inhibitory effect on host APC function. Fig. 1 (A) NOD2 deficiency of the hematopoietic system aggravatges GVHD. Chemeric mice with NOD2 deficiency either in the hematopoietic system or in the non-hematopoietic system were created by syngeneic BMT (B6 WT → B6 NOD2-/- or B6 NOD2-/→ B6 WT). After 90 days, lethally irradiated (11 Gy) B6 WT versus B6 NOD2-/- versus chemeric allo-BMT recipients were transplanted with 5×106 B10BR TCD-BM or 5×106 LP TCD-BM + 2×106 B10BR T Cells or 3×106 LP T cells. combined date from two independent experiments are shown; n = 16/group. (B) NOD2 deficiency of the hematopoietic system aggravates experimental colitis. First, chemeric mice with NOD2 deficiency either in the hematopoietic system or in the non-hematopoietic system were created by syngeneic BMT (B6 WT→B6 NOD2-/- or B6 NOD2-/-→ B6 WT). After 90 days, TNBS colitis (5 mg TNBS in 50% ethanol) was induced; colons were harvested at day+3 after induction of colitis; combined data from two independent experiments are shown; n=8 / group. Fig. 1. (A) NOD2 deficiency of the hematopoietic system aggravatges GVHD. Chemeric mice with NOD2 deficiency either in the hematopoietic system or in the non-hematopoietic system were created by syngeneic BMT (B6 WT → B6 NOD2-/- or B6 NOD2-/→ B6 WT). After 90 days, lethally irradiated (11 Gy) B6 WT versus B6 NOD2-/- versus chemeric allo-BMT recipients were transplanted with 5×106 B10BR TCD-BM or 5×106 LP TCD-BM + 2×106 B10BR T Cells or 3×106 LP T cells. combined date from two independent experiments are shown; n = 16/group. (B) NOD2 deficiency of the hematopoietic system aggravates experimental colitis. First, chemeric mice with NOD2 deficiency either in the hematopoietic system or in the non-hematopoietic system were created by syngeneic BMT (B6 WT→B6 NOD2-/- or B6 NOD2-/-→ B6 WT). After 90 days, TNBS colitis (5 mg TNBS in 50% ethanol) was induced; colons were harvested at day+3 after induction of colitis; combined data from two independent experiments are shown; n=8 / group. Disclosures: No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document