Absence of Inducible Costimulator (ICOS) on Alloreactive T Cells Reduces Graft-versus-Host-Disease While Leaving Graft-Versus-Tumor Activity Intact.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 592-592
Author(s):  
Vanessa M. Hubbard ◽  
Jeffrey M. Eng ◽  
Kartono H. Tjoe ◽  
Teresa Ramirez-Montagut ◽  
Stephanie J. Muriglan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Graft Versus Host ◽  
Cell Numbers ◽  
Alloreactive T Cells ◽  
Inducible Costimulator ◽  
Target Organs ◽  
Donor T Cells ◽  
Ifn Γ

Abstract Inducible costimulator (ICOS) is a member of the B7 family that is expressed on activated and memory T cells and is involved in the regulation of TH1 and TH2 effector cytokine production after CD3/TCR stimulation. Studies with ICOS inhibition or ICOS−/− recipients have demonstrated prolonged allograft survival after heart or liver transplantation in animal models. To study the role of ICOS expression on alloreactive T cells in graft-versus-host disease (GVHD), we used allogeneic MHC class I and II disparate hematopoietic stem cell transplantation (allo-HSCT) models. We first analyzed the expression of ICOS by transferring CFSE-labeled donor T cells into irradiated allogeneic recipients and observed an increased expression of ICOS on alloreactive T cells compared to non-alloreactive T cells. We then studied B6-ICOS−/− alloreactive T cells and found intact proliferation in vivo (as determined by adoptive transfer of CFSE labeled T cells and donor T cell numbers in the spleen of allo-HSCT recipients), intact cytotoxicity, intact up regulation of activation markers, but decreased IFN-γ production in vitro. We then performed GVHD experiments in two models with full MHC class I and II disparity and observed significantly less GVHD morbidity and mortality in recipients of ICOS−/− donor T cells. Furthermore, histopathological analysis demonstrated less GVHD in all target organs (skin, liver, small bowel and large bowel) of recipients of ICOS−/− splenic T cells compared to recipients of wild type T cells. We harvested target organs (spleen, thymus, liver and gut) on days 7, 14, and 21 to examine donor T cell content (naïve and activated T cells) and found no significant difference in the total T cell numbers and subpopulations. Interestingly, in GVHD/graft-versus-tumor (GVT) experiments, ICOS−/− donor T cells displayed intact GVT activity, while their GVH activity was diminished. We then tested the levels of IFN-γ in the sera of mice undergoing GVHD and observed decreased serum levels in recipients of B6-ICOS−/− T cells. In conclusion, alloreactive ICOS−/− donor T cells display less GVHD morbidity and mortality due to decreased IFN-γ production, while proliferation, infiltration and GVT activity remain intact. These data suggests that strategies to inhibit ICOS could be useful for the prevention and/or treatment of GVHD in recipients of an allo-HSCT.

Donor BM Dendritic Cells Expressing IDO Limit Graft-Versus-Host Disease After Allogeneic Bone Marrow Transplant.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1331-1331
Author(s):  
Ying Lu ◽  
Wayne Harris ◽  
Jian-Ming Li ◽  
Edmund K. Waller
Keyword(s):  
T Cells ◽  
T Cell ◽  
Marrow Transplant ◽  
Allogeneic Bone ◽  
Transplant Recipients ◽  
Hematopoietic Stem ◽  
Graft Versus Host ◽  
Donor T Cells ◽  
Ifn Γ ◽  
Th1 Polarization

Abstract Abstract 1331 Poster Board I-353 Background In contrast to the essential role of host dendritic cells (DC) in the initiation of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) reactions, less is known about the effects of donor DC on T cells in these processes. We have previously reported that adding donor BM plasmacytoid DC (pDC) progenitors to a murine graft composed of purified hematopoietic stem cells (HSC) and T-cells increased donor activation and Th1 polarization leading to enhanced GVL activity without increasing GVHD (Li et al. 2007 Blood 110:2181), while larger numbers of human donor pDC were associated with less GVL activity following allogeneic bone marrow transplant (BMT) (Waller et al. 2001 Blood 97:2948). To explore the dissociation of GVHD from GVL we tested the hypothesis that activation of donor T-cells by donor pDC leads to reciprocal induction of indoleamine 2,3-dioxygenase (IDO) expression and immune counter-regulatory activity by donor DC that limits donor T-cell allo-reactivity. Methods pDC precursors were purified by high-speed FACS from un-stimulated BM harvested from wild type (WT) and IDO knock-out (IKO) mice. T-cell proliferation and immune polarization in response to indirect antigen presentation by syngenic DC was measured in mixed lymphocyte reaction (MLR) and by recovery of CFSE-labeled donor T-cells from allogeneic transplant recipients. IDO expression in DC was measured by FACS and intracellular staining using pDC from IKO BM as a negative staining control. FACS-purified 5 × 104 pDC either from WT mice or from IKO mice in combination with 3 × 103 c-kit+ Sca-1+ hematopoietic stem cells (HSC) and 3 × 105 T-cells were transplanted in MHC mismatched C57BL/6→B10.BR model following lethal irradiation. Results FACS-purified lineage−CD11cloCD11b− pDC expressed B220 (72%), CD90 (51%), and CD317 (PDCA-1) (93%), had low levels of MHC-II, partial expression of CD4, and lacked expression of CD24, CD80, CD86 and NK cell or granulocytic markers. IDO expression in purified pDC was up regulated by IFN-γ produced by syngenic T-cells in vitro in one-way MLR. In vivo proliferation of CFSE-labeled donor T-cells was enhanced in mice that received pDC from either WT or IKO mice. Co-transplantation of IKO pDC led to higher proliferation rates of CD8+ T-cells but not CD4+ T-cells compared with the proliferation of corresponding donor T-cell subset co-transplanted with WT DC. The incidence and severity of GVHD (weight loss and GVHD score) were markedly increased in recipients receiving pDC from IKO mice as compared with mice receiving WT pDC. The enhanced GVL activity of donor T-cells induced by transplanted donor WT pDC was abolished when IKO pDC were transplanted into tumor-bearing recipients. Transplanting WT donor pDC led to larger numbers of donor-derived CD4+CD25+Foxp3+ T-reg cells in the spleens of transplant recipients compared with mice receiving IKO pDC (p<0.01) in combination with purified HSC and T-cells. Conclusions Taken together, our data suggest IDO expression in pDC as a critical downstream event that inhibits continued T-cell activation and GVHD. We propose a feedback model in which donor pDC initially induce Th1 polarization of activated donor CD8+ T-cells that secret high levels of IFN-γ. IDO expressed by donor pDC in response to local IFN-γ subsequently induces a counter-regulatory effect including the generation of T-reg and down-modulation of CD8+ T-cell allo-reactivity and proliferation, limiting GVHD while preserving the GVL activity of donor T-cells. Disclosures No relevant conflicts of interest to declare.

Division rate and phenotypic differences discriminate alloreactive and nonalloreactive T cells transferred in lethally irradiated mice

Blood ◽  
2001 ◽  
Vol 98 (10) ◽  
pp. 3156-3158 ◽  
Author(s):  
Sébastien Maury ◽  
Benoı̂t Salomon ◽  
David Klatzmann ◽  
José L. Cohen
Keyword(s):  
T Cells ◽  
T Cell ◽  
Division Rate ◽  
Hematopoietic Stem ◽  
Phenotypic Differences ◽  
Graft Versus Host ◽  
Alloreactive T Cells ◽  
Donor T Cells ◽  
Life Threatening ◽  
T Cell Transfer

Abstract After non-T-cell–depleted allogeneic hematopoietic stem cell transplantation (HSCT), both alloreactive and homeostatic signals drive proliferation of donor T cells. Host-reactive donor T cells, which proliferate on alloantigen stimulation, are responsible for the life-threatening graft-versus-host disease. Non–host-reactive donor T cells, which proliferate in response to homeostatic signals, contribute to the beneficial peripheral T-cell reconstitution. The elimination of alloreactive T cells is a major therapeutic challenge for HSCT and would greatly benefit from their specific identification. After T-cell transfer in lymphopenic recipients, the present results show that alloreactive T cells rapidly divided; up-regulated CD69, CD25, and CD4 molecules; and down-regulated CD62L. In contrast, nonalloreactive T cells started to divide later and did not up-regulate CD69, CD25, and CD4. Thus, these 2 cell populations can be effectively discriminated. This should facilitate the specific depletion of alloreactive T cells in allogeneic HSCT.

scholarly journals β2- Adrenergic Signaling Regulates Graft Versus Host Disease after Allogenic Transplantation While Preserving Graft Versus Leukemia Effect

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1915-1915 ◽  
Author(s):  
Hemn Mohammadpour ◽  
Joseph L. Sarow ◽  
George L. Chen ◽  
Cameron R. MacDonald ◽  
Umesh Sharma ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Adrenergic Receptor ◽  
Graft Versus Host ◽  
Graft Versus Leukemia ◽  
Donor T Cells ◽  
Β2 Adrenergic Receptor ◽  
Ifn Γ

β2 adrenergic receptor signaling is a key regulator of various immune cells, including T cells; however, its role in T cell function in the context of graft versus host disease (GvHD) is poorly understood. We previously showed that housing mice at thermoneutral temperature (TT; 30°C), which reduces systemic adrenergic stress, increased the incidence and severity of GvHD after allogeneic hematopoietic cell transplant (allo-HCT) compared to mice housed at standard temperature (ST; 22°C) which exerts a mild but chronic adrenergic stress (Leigh et al J Immunol 2015). The increased incidence and severity of GvHD in TT mice can be reversed by the administration of a β2-adrenergic receptor (β2-AR) agonist, suggesting an important role of epinephrine and norepinephrine in allo-HCT outcome (Leigh et al., J. Immunol 2015; Mohammadpour et al J Immunol 2018). We investigated the mechanisms and downstream events of β2-AR signaling in donor T cells after allo-HCT by using β2-AR knockout (β2-AR-/-) mice and commercially available β2-AR agonists. The main goal here was to explore whether signaling through β2-AR in donor T cells could control GvHD incidence and severity without minimizing the graft-versus leukemia (GvL) effect. We utilized both a major MHC-mismatch C57B6 (H-2kb) into BALB/c (H-2kd) model and a MHC-matched, multiple minor histocompatibility antigen (miHA) mismatched B6 (H-2kb) into C3H/SW (H-2kb) model. Recipient BALB/c and C3H/SW WT mice were lethally irradiated with 850 and 1100 cGy respectively and injected by tail vein with T cell depleted bone marrow (TCD-BM) alone (3 ×106) or TCD-BM and splenic T cells derived from allogeneic WT or β2-AR-/- B6 donors (0.7 × 106 T cells in B6 → BALB/c and 1.5 × 106 in B6 → C3H/SW). We found that donor T cells express β2-AR after allo-HCT and that β2-AR expression on WT T cells plays an important role in controlling GvHD, as evidenced by less severe weight loss, and increased survival compared to mice receiving β2-AR-/- donor T cells (Figure 1A). Histopathologic examination showed that β2-AR-/- T cells induced more damage in the small and large intestine. To explore further the mechanism(s) by which β2-AR signaling controls the severity of GvHD, we used NanoString analysis and discovered that β2-AR-/- T cells have the Th1 phenotype with an increase in Tbx21, Ifng, Irf8 and Emoes genes, while WT CD4+ T cells had higher levels of Th2 and Treg associated genes, including Foxp3, Ptgs5, Tgfb2, Il10, Il21 and Il22. We also observed a significant increase in the inflammatory cytokines IFN-γ and IL-17 in β2-AR-/- CD4+ T cells from the spleen and liver on days 7 and 14 after allo-HCT as compared to WT T cells (Figure 1B), while the expression of IL-10 was significantly higher in WT T cells compared to β2-AR-/- T cells (P< 0.01). We next sought to determine whether GvL may be affected by use of long acting β2-AR agonist (Bambuterol) to control GvHD. Bambuterol was administered daily at a dose of 1mg/kg from day 0. We observed that Bambuterol controlled the severity and mortality of GvHD after allo-HCT in both major and minor mismatch mouse models, as evidenced by reduced weight loss and an improved clinical score and survival rate in mice receiving Bambuterol compared to vehicle (P<0.001). We showed that treatment increased the expression of IL-10 and decreased the expression of IFN-γ and IL-17 in CD4+ T cells. Interestingly, we found that β2-AR agonist treatment significantly increased the generation of myeloid derived suppressor cells (MDSCs) from WT BM without any effect on β2-AR-/- BM both in vitro and in vivo, suggesting an important role of β2-AR signaling in the generation of MDSCs. To investigate the effect of Bambuterol on GvL, the A20 lymphoma cell line was injected 4 hours before allo-HCT. Using two different doses of T cells (0.5 × 106 and 0.2 × 106) in B6 → BALB/c model, we found that Bambuterol preserved GvL by inducing CD44+ CD62L- NKG2D+ effector cells and CD44+ CD62L+ central memory cells. Since β2-AR agonists can affect cardiac function, we measured heart rate (HR) and blood pressure (BP) using a tail-cuff. There was no difference in BP and HR at day 21 and 28 after allo-HCT between mice receiving Bambuterol compared to mice receiving vehicle. In conclusion, these data reveal how β-AR signaling can influence donor T cell differentiation and function in murine GvHD models without decreasing GvL effect pointing to the feasibility of manipulation of β2-AR signaling to ameliorate clinical GvHD. Disclosures No relevant conflicts of interest to declare.

Deletion of AMP-Activated Protein Kinase (AMPK) in Donor T Cells Protects Against Graft-Verus-Host Disease through Control of Regulatory T Cell Expansion and Target Organ Infiltration

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 806-806 ◽  
Author(s):  
Kevin Beezhold ◽  
Nathan Moore ◽  
Pailin Chiaranunt ◽  
Rebecca Brown ◽  
Craig A. Byersdorfer
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lower Percentage ◽  
Cd4 Cells ◽  
Post Transplant ◽  
Alloreactive T Cells ◽  
Target Organs ◽  
Donor Cells ◽  
Donor T Cells

Abstract Allogeneic hematopoietic stem cell transplantation (alloHSCT) represents a curative treatment for high-risk leukemia and a number of non-malignant hematologic disorders. However, the therapeutic use of alloHSCT remains limited by acute graft-versus-host disease (GVHD), where activated donor T cells attack and destroy host tissues in the skin, gastrointestinal tract, and liver. We have previously shown that the alloreactive T cells responsible for GVHD increase their dependence on the oxidation of fat relative to either syngeneic or naive T cells. To explore this adaptation mechanistically, we studied the role of AMPK, an intracellular energy sensor and known driver of fat oxidation, in donor T cells during GVHD. Alloreactive T cells increased phosphorylation of AMPK as early as day 3 post-transplant, with up-regulation in pathways both up- and downstream of AMPK. Changes in phosphorylation were up to 8-fold higher in alloreactive T cells compared to naive T cells or syngeneic controls (p=0.0003). We then investigated the role of AMPK during GVHD pathogenesis using donor cells deficient in AMPK (from AMPKα1fl/flα2fl/fl x CD4-Cre mice). AMPK-/- T cells caused significantly less GVHD in both major-MHC and minor-histocompatibility mismatch models of GVHD (Figure 1A), with a coordinated decrease in the number of donor T cells recovered on day 7 post-transplant (3.15 +/- 0.49x106 versus1.87 +/- 0.53x106, p=0.0006, wildtype (wt) versus AMPK-/- respectively). Importantly, expansion of syngeneic T cells was unaffected by AMPK deficiency (Figure 1B). We next investigated the ability of AMPK-/- T cells to mount effective cytotoxic and anti-leukemia responses. AMPK-/- T cells demonstrated equivalent cytotoxicity against MHC-mismatched targets both in vitro and in vivo and differentiated in similar proportions into cytokine-producing cells (IFN-γ, TNFα, IL-17, and IL-4). We then assessed graft-versus-leukemia (GVL) potential in AMPK-/- cells using a GVL model with high tumor burden. AMPK-/- T cells exhibited equivalent clearance of p815 leukemia cells on day 13 post-transplant (Figure 2A), and extended survival of recipient mice similarly to wt T cells (Figure 2B). To elucidate possible mechanisms underlying this separation of GVL and GVHD responses, we evaluated metabolic pathways in wt and AMPK-/- T cells recovered on day 7. To our surprise, rates of fatty acid oxidation were identical between wt and AMPK-/- T cells and loss of AMPK did not impact alloreactive T autophagy, nor impair signaling downstream of mammalian target of rapamycin. To define the mechanism underlying AMPK-/- benefits, we quantitated levels of regulatory T cells (Treg) on day 7 post-transplant. In contrast to expectation, both the percentage and total number of Treg increased in mice receiving AMPK-/- T cells (0.85 +/- 0.32x104 vs. 1.69 +/- 0.34x104, wt vs. AMPK-/-, p=0.004). Loss of AMPK facilitated donor Treg expansion, as elimination of FoxP3+ cells prior to transplantation abrogated differences between wt and AMPK-/- donors on day 7. Importantly, Treg levels were equal in wt versus AMPK-/- donors prior to transplantation. Finally, we assessed the ability of AMPK-/- T cells to infiltrate into GVHD target organs. As shown in Figure 3, peri-portal infiltration of AMPK-/- cells was significantly reduced compared to wt T cells, and infiltrates in recipients of AMPK-/- cells contained many fewer CD3+ T cells per high-powered field, with CD3+ cells representing a lower percentage of cells overall. Decreased hepatic infiltration correlated with a lower percentage of circulating CD4+ cells and lower levels of the integrin pair α4β7 (55.2 +/- 1.4% versus 47.2 +/- 2.8% α4β7Hi cells, p=0.0017, wt vs. AMPK-/-). In conclusion, deletion of AMPK in donor T cells decreases GVHD severity but spares anti-leukemia responses and preserves homeostatic immune reconstitution. Mechanistically, this occurs through a decrease in pathogenic T cell numbers, an increase in the number and percentage of Treg cells, fewer circulating CD4+ cells, and decreased infiltration of donor cells into target organs. From these findings, we conclude that AMPK represents a clinically relevant target in donor T cells pre-transplant and are actively exploring ways to translate this exciting therapy into clinical practice. Disclosures No relevant conflicts of interest to declare.

scholarly journals A repertoire-independent and cell-intrinsic defect in murine GVHD induction by effector memory T cells

Blood ◽  
2011 ◽  
Vol 118 (23) ◽  
pp. 6209-6219 ◽  
Author(s):  
Kathryn W. Juchem ◽  
Britt E. Anderson ◽  
Cuiling Zhang ◽  
Jennifer M. McNiff ◽  
Anthony J. Demetris ◽  
...  
Keyword(s):  
T Cells ◽  
Memory T Cells ◽  
Effector Memory ◽  
Intrinsic Defect ◽  
Intrinsic Properties ◽  
Graft Versus Host ◽  
Effector Memory T Cells ◽  
Alloreactive T Cells ◽  
Donor T Cells ◽  
Ifn Γ

Abstract Effector memory T cells (TEM) do not cause graft-versus-host disease (GVHD), though why this is has not been elucidated. To compare the fates of alloreactive naive (TN) or memory (TM) T cells, we developed a model of GVHD in which donor T cells express a transgene-encoded TCR specific for an antigenic peptide that is ubiquitously expressed in the recipient. Small numbers of naive TCR transgenic (Tg) T cells induced a robust syndrome of GVHD in transplanted recipients. We then used an established method to convert TCR Tg cells to TM and tested these for GVHD induction. This allowed us to control for the potentially different frequencies of alloreactive T cells among TN and TM, and to track fates of alloreactive T cells after transplantation. TEM caused minimal, transient GVHD whereas central memory T cells (TCM) caused potent GVHD. Surprisingly, TEM were not inert: they, engrafted, homed to target tissues, and proliferated extensively, but they produced less IFN-γ and their expansion in target tissues was limited at later time points, and local proliferation was reduced. Thus, cell-intrinsic properties independent of repertoire explain the impairment of TEM, which can initiate but cannot sustain expansion and tissue damage.

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 Blockade of Interleukin 27 Signaling Attenuates Graft Versus Host Disease By Augmenting CD4+ and CD8+ Regulatory T Cell Reconstitution

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 150-150
Author(s):  
Ludovic Belle ◽  
Kimberle A. Agle ◽  
Vivian Zhou ◽  
Vanessa Yuan ◽  
Jie Sun ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Graft Versus Host Disease ◽  
Cd8 T Cells ◽  
Regulatory T Cell ◽  
Wild Type ◽  
Host Disease ◽  
Graft Versus Host ◽  
Target Organs ◽  
Ifn Γ

Abstract The interleukin-6 (IL-6) cytokine superfamily (i.e. IL-6, IL-12, and IL-23) plays a major role in the modulation of inflammatory and regulatory pathways during graft versus host disease (GVHD). IL-27, a recently discovered member of this family, is a heterodimeric cytokine that is composed of the p28 and EBI3 subunits and signals through a heterodimeric receptor composed of WSX-1 and gp130. Notably, IL-6 also uses gp130 as a signaling component which biologically links IL-27 and IL-6. IL-27 has been shown to have opposing proinflammatory and immunoregulatory effects, but its role in GVHD is not well understood. To define the functional significance of IL-27, lethally irradiated Balb/c (H-2d) mice were transplanted with C57BL/6J (H-2b) BM and spleen cells, and then treated with an anti-IL-27p28-specific antibody on days 0 and +6. p28 antibody-treated animals had significantly improved weight recovery and overall survival (47% versus 0% survival at day 60, p=0.002), as well as reduced numbers of proinflammatory CD4+ and CD8+ IFN-γ+ T cells in GVHD target organs, when compared to isotype control antibody-treated mice. A similar outcome was observed in an MHC-matched, minor antigen disparate model (B6→Balb.B), indicating that this was not a strain-specific phenomenon. Given the similarities between IL-6 and IL-27, we examined whether blockade of IL-27 promoted regulatory T cell (Treg) reconstitution as has been observed with inhibition of IL-6 signaling. Recipients transplanted with BM grafts from B6 Foxp3EGFP reporter animals and treated with p28 antibody had a significant increase in the number of CD4+ nTregs, CD4+ iTregs and CD8+ iTregs in GVHD target organs, indicating that blockade of IL-27 augmented global Treg reconstitution. In fact, inhibition of IL-27 was more effective at augmenting Treg reconstitution than comparable antibody blockade of IL-6. To further elucidate the role of IL-27, we employed transgenic IL-27−/− and IL-27R−/− animals to dissect the relevant contributions of donor and recipient populations. Paradoxically, we observed that transplantation with IL-27−/− donor grafts exacerbated GVHD mortality and augmented accumulation of proinflammatory T cells, whereas transplantation of recipient IL-27−/− mice with wild type grafts had no effect on transplant outcomes. This discordance between antibody-based and genetic studies was unexpected and led us to consider whether there were steady state alterations in T cells from IL-27−/− animals that biased these cells towards a proinflammatory phenotype. To that end, we observed that naive CD8+ T cells from IL-27−/− mice had greater IFN-γ production than wild type cells after in vitro polyclonal stimulation and CD4+ nTregs from these animals had diminished expression of CXCR3 which is critical for Treg trafficking into inflamed tissue sites. Thus, the lack of endogenous IL-27 resulted in intrinsic immune dysregulation which led to an exacerbation of GVHD after transfer of these T cells into recipients. To resolve this paradox, we employed IL-27R−/− (WSX-1−/−) mice and demonstrated that mice transplanted with IL-27R−/− grafts had enhanced weight recovery and survival providing confirmation that blockade of IL-27 signaling reduced GVHD. In addition, using IL-27R−/− Foxp3EGFP reporter mice, we observed increased frequencies and numbers of CD4+ and CD8+ Foxp3+ T cells in mice reconstituted with IL-27R−/− grafts, confirming results observed with p28 antibody blockade. Since IL-10 is a mechanism by which CD4+ Tregs suppress GVHD and IL-27 has been shown to enhance T cell-derived IL-10 secretion in nontransplant models, we examined whether IL-27 blockade adversely affected IL-10 production by Tregs. Recipients transplanted with marrow grafts from IL-10.BitFoxp3EGFP dual reporter animals and treated with p28 antibody had a significant reduction in the frequency of IL-10-producing conventional CD4+ and CD8+ T cells in GVHD target organs. Notably, however, there was no difference in the frequency of CD4+ Foxp3+ IL-10+ T cells, indicating that blockade of IL-27 signaling preferentially affected conventional T cells and had no adverse effect on CD4+ Foxp3+ T cell-derived IL-10 production. In summary, these studies demonstrate that blockade of IL-27 signaling potently augments Treg reconstitution leading to a reduction in the severity of GVHD and may therefore represent a novel strategy to reduce mortality from this disease in man. Disclosures No relevant conflicts of interest to declare.

scholarly journals Absence of inducible costimulator on alloreactive T cells reduces graft versus host disease and induces Th2 deviation

Blood ◽  
2005 ◽  
Vol 106 (9) ◽  
pp. 3285-3292 ◽  
Author(s):  
Vanessa M. Hubbard ◽  
Jeffrey M. Eng ◽  
Teresa Ramirez-Montagut ◽  
Kartono H. Tjoe ◽  
Stephanie J. Muriglan ◽  
...  
Keyword(s):  
T Cells ◽  
Graft Versus Host Disease ◽  
Interleukin 4 ◽  
Activated T Cells ◽  
Hematopoietic Stem ◽  
Host Disease ◽  
Graft Versus Host ◽  
Alloreactive T Cells ◽  
Inducible Costimulator ◽  
Donor T Cells

AbstractInducible costimulator (ICOS) is expressed on activated and memory T cells and is involved in the regulation of cytokine production. We studied the role of ICOS on alloreactive T cells in graft versus host disease (GVHD) and determined that ICOS expression was up-regulated on alloreactive T cells in recipients of an allogeneic hematopoietic stem cell transplantation (allo-HSCT) with GVHD. We compared ICOS-/- T cells with wild-type (WT) T cells in 2 GVHD models. In both models, recipients of ICOS-/- T cells demonstrated significantly less GVHD morbidity and mortality, which was associated with less intestinal and hepatic GVHD but increased cutaneous GVHD. In addition, recipients of ICOS-/- donor T cells displayed a slight decrease in graft versus leukemia (GVL) activity. Further analysis of alloreactive ICOS-/- T cells showed no defect in activation, proliferation, cytotoxicity, and target organ infiltration. Recipients of ICOS-/- T cells had decreased serum levels of interferon-γ (IFN-γ), while interleukin-4 (IL-4) and IL-10 levels were increased, suggesting that alloreactive ICOS-/- T cells are skewed toward T helper-2 (Th2) differentiation. These data suggest a novel role for ICOS in the regulation of Th1/Th2 development of activated T cells. In conclusion, alloreactive ICOS-/- donor T cells induce less GVHD due to a Th2 immune deviation while GVL activity is slightly diminished.

Clonal Expansion of Graft-Versus-Host Reactive CD8+ T Cells Is Dissociated from Full Effector Differentiation Following Delayed DLI.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2170-2170
Author(s):  
Ronjon Chakraverty ◽  
Barry Flutter ◽  
Hyeon-Seok Eom ◽  
Farnaz Fallah-Arani ◽  
Guiling Zhao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Population ◽  
Cd8 T Cells ◽  
Granzyme B ◽  
Cd8 T Cell ◽  
Host Environment ◽  
Graft Versus Host ◽  
Donor T Cells ◽  
Ifn Γ

Abstract Extrinsic factors within the host environment are crucial in determining recruitment of graft-versus-host (GVH)-reactive T cells to peripheral tissues and the capacity of these cells to induce graft-versus-host disease (GVHD). In this study, we have examined how the host environment influences graft-versus-leukemia (GVL) activity. Transfer of small numbers of allogeneic T cells to freshly irradiated (TBI allo) mice induces both GVL and GVHD, whereas transfer of much higher numbers of T cells to established (&gt;8 weeks) mixed chimeras (MC) can induce GVL without GVHD. Using an EL4 tumor protection assay and low doses of B10.A splenocytes (3 × 10e6, a dose 1 log lower than normally transferred to MC to induce GVL), we observed that tumor-free survival of recipient mice was greater following transfer to TBI allo B6 recipients than in B6 + B10.A → B6 MC. To determine the mechanisms for this disparity, we used a BALB/c recipient/B6 donor strain combination, in which we could track the distribution of donor T cells within secondary lymphoid organs and bone marrow (BM) following transfer to TBI allo or MC recipients. Despite similar expansions within the spleen, there was a significant delay in the accumulation of polyclonal donor T cells (B6 CD45.1) and transgenic 2C GVH-reactive CD8+ T-cells (bearing TCR specific for recipient antigen) in the BM of MC compared to TBI allo mice. Moreover, in vivo cytotoxicity of host B cell targets occurred rapidly and was virtually complete in TBI allo recipients, but was absent in MC even at late time points. To evaluate the acquisition of effector functions in a clonal GVH-reactive CD8+ T cell population, we sorted 2C T cells at intervals following transfer and performed quantitative RT-PCR of molecules linked to effector differentiation. Strikingly, transcription of IFN-γ, granzyme B and TNF-α was significantly higher in cells derived from TBI allo hosts compared to MC. Similar differences in IFN-γ and granzyme B protein expression were confirmed in the polyclonal donor CD8+ T cell population. Since, full GVL activity might also depend upon the survival of GVH-reactive CTL, we also examined the viability of donor T cells during the initial response in both environments. We observed higher rates of sustained 2C CD8+ T cell apoptosis (as indicated by annexin V staining) following T cell transfer to MC. Furthermore, we also detected lower expression of common γ chain cytokine receptors that mediate responsiveness to IL-2, IL-7 and IL-15, upon donor T cells from MC. However, following secondary co-transfer to syngeneic recipients for 21 days, memory phenotype polyclonal donor CD8+ T cells derived from established MC (CD45.1+) were recovered to a greater extent than T cells initially derived from TBI allo mice (Thy1.1+), arguing against any intrinsic defect in the viability of GVH-reactive T cell populations emerging in the former setting. Indeed, when co-cultured in the presence of individual cytokines, MC-derived CD8+ T cells maintained viability to a greater (IL-2, IL-7) or equivalent (IL-15) extent as TBI allo-derived cells. Taken together, these data suggest that disparity in GVL activity following to TBI allo recipients and MC can be explained by differences in the effector function and survival of anti-host CTL in quiescent MC environment. Reduced GVL activity of donor T cells on a per-cell basis in MC can be compensated for by transferring greater numbers of cells.

T-Bet Is Critical for the Development of Acute Graft-Versus-Host Disease Through Controlling T Cell Differentiation and Function

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 452-452
Author(s):  
Jianing Fu ◽  
Dapeng Wang ◽  
Yu Yu ◽  
Kane Kaosaard ◽  
Chen Liu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Th17 Cells ◽  
Acute Gvhd ◽  
T Cell Infiltration ◽  
Target Organs ◽  
Donor T Cells ◽  
Ifn Γ

Abstract Abstract 452 Background: Allogeneic hematopoietic cell transplantation (HCT) offers great promise for the treatment of hematologic malignancies. However, HCT benefits are frequently offset by graft-versus-host disease (GVHD). Donor T cells can differentiate into Th1 or Th17 subset that contribute to GVHD. The T-box transcription factor T-bet is important for promoting the differentiation of naïve CD4+T cells into Th1 phenotype, while simultaneously inhibiting Th2 and Th17 lineage commitment. Published data indicate that donor T cells deficient for IFN-γ induce exacerbated GVHD. In contrast, our recent study showed that T cells deficient for T-bet were impaired in the induction of GVHD. Given T-bet is a master regulator for the differentiation into Th1 cells that produce IFN-γ, the underlining mechanisms accounted for the distinct outcomes caused by T-bet- versus IFN-γ-deficient donor T cells are not clear. Method: We evaluated the roles of T-bet and IFN-γ in acute GVHD induced by naïve CD4+ T cells or polarized Th17 cells using murine allogeneic bone marrow transplantation (allo-BMT) model. WT, T-bet knockout (KO) and IFN-γ KO mice on C57BL/6 (B6) background were used as donors, and lethally irradiated BALB/c mice were used as recipients. Pathologic analysis and serum cytokine detection were done 14 days after adoptive transfer of WT, T-bet–/–, and IFN-γ–/– CD4+ T cells. Using microarray technology, gene expression profile on donor T cells was analyzed 7 days after adoptive transfer by sorting donor-derived CD4+ T cells from the recipients of WT, T-bet–/– or IFN-γ–/– CD4+ T cells. Results: We compared the ability of WT, T-bet–/–, and IFN-γ–/– CD4 T cells in the induction of acute GVHD. In the comparison with WT cells, IFN-γ–/– CD4 T cells caused similar or even more severe GVHD as expected. In sharp contrast, T-bet–/– CD4 T cells induced much ameliorated GVHD, as significantly higher survival and less body weight loss were observed in the recipients of T-bet–/–T cells. Pathology study on GVHD target organs showed that recipients of T-bet–/– donor T cells had markedly reduced T cell infiltration and tissue damage in liver, gut, and skin, when compared with those of WT or IFN-γ–/– T cells. Reduced GVHD in the recipients of T-bet–/– T cells was consistent with significantly lower levels of pathogenic cytokines IFN-γ, TNF-α, and IL-2 but higher IL-10 (anti-inflammatory), IL-6 (Th17 related) and IL-4 (Th2 related) in serum as compared with those in the recipients of WT T cells. Mechanistic studies in vitro revealed that T-bet–/– CD4 T cells expressed significantly lower levels of IFN-γ, CXCR3 (Th1 specific chemokine receptor) and CD122 (T cell activation marker), but higher levels of IL-17 (Th17 cytokine) and CCR6 (Th17 specific chemokine receptor) compared with WT CD4 T cells, indicating that T-bet–/– T cells impaired in differentiating into Th1 cells and instead into Th17 cells. Given Th17 subset only is capable of causing GVHD and T-bet–/– T cells are prone to Th17-differentiation, we assessed the role of T-bet or IFN-γ in the development of GVHD by comparing the pathogenicity of in vitro polarized WT, T-bet–/– and IFN-γ–/– Th17 cells. While IFN-γ–/– Th17 cells had a comparable ability to cause GVHD compared with WT Th17 cells, T-bet–/– Th17 cells had reduced pathogenicity, and caused ameliorated GVHD. Furthermore, microarray analysis identified genes that are regulated by T-bet but independent of IFN-γ, including Cxcr3, Ccr5, Ccl3, Ccl4, Klrc1, Klrd1, Nkg7 and Pdcd1, which may explain the compromised ability of T-bet−/− not IFN-γ–/–T cells in the induction of GVHD. Conclusions: We conclude that T-bet is required for Th1 differentiation and optimal function of Th17 cells, and it can also control T cell infiltration into GVHD target organs by regulating chemokines and their receptors. Thus, failure in Th1 generation, migration and reduced activity of polarized Th17 cells are likely accounted for impaired ability of T-bet−/− CD4 T cells in the induction of acute GVHD. The current study suggests that targeting T-bet or regulating its downstream effectors independent of IFN-γ may be a promising strategy to control GVHD after allogeneic HCT in clinic. Disclosures: No relevant conflicts of interest to declare.

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