Interruption of OX40L signaling prevents costimulation blockade–resistant allograft rejection

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Abstract

The potential of costimulation blockade to serve as a novel transplant immunosuppression strategy has been explored for over 20 years, culminating in the recent clinical approval of belatacept for renal transplant patients. Despite improving long-term graft function and survival compared with calcineurin inhibitors, clinical acceptance of belatacept has been hindered by elevated rates of acute rejection. We examined the signaling pathways required to activate costimulation blockade–resistant alloreactive T cells and identified the OX40/OX40L secondary costimulatory pathway as a promising target. We next sought to improve the clinical efficacy of traditional costimulation blockade using belatacept by coupling it with anti-OX40L. Using a murine transplant model, we demonstrate that combined blockade enhances the suppression of alloreactive T cell proliferation and effector functions including both cytokine release and cytotoxic degranulation. We also show that anti-OX40L may be particularly useful in targeting alloreactive memory T cell responses that are relatively unaffected by traditional costimulation blockade regimens. Finally, we translated this therapy to a clinically relevant nonhuman primate renal transplant model, validating the efficacy of this regimen in a potentially novel steroid- and calcineurin inhibitor–free immunosuppression regimen.

Authors

William H. Kitchens, Ying Dong, David V. Mathews, Cynthia P. Breeden, Elizabeth Strobert, Maria E. Fuentes, Christian P. Larsen, Mandy L. Ford, Andrew B. Adams

Loss of immune homeostasis dictates SHIV rebound after stem-cell transplantation

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Abstract

The conditioning regimen used as part of the Berlin patient’s hematopoietic cell transplant likely contributed to his eradication of HIV infection. We studied the impact of conditioning in simian-human immunodeficiency virus–infected (SHIV-infected) macaques suppressed by combination antiretroviral therapy (cART). The conditioning regimen resulted in a dramatic, but incomplete depletion of CD4⁺ and CD8⁺ T cells and CD20⁺ B cells, increased T cell activation and exhaustion, and a significant loss of SHIV-specific Abs. The disrupted T cell homeostasis and markers of microbial translocation positively correlated with an increased viral rebound after cART interruption. Quantitative viral outgrowth and Tat/rev–induced limiting dilution assays showed that the size of the latent SHIV reservoir did not correlate with viral rebound. These findings identify perturbations of the immune system as a mechanism for the failure of autologous transplantation to eradicate HIV. Thus, transplantation strategies may be improved by incorporating immune modulators to prevent disrupted homeostasis, and gene therapy to protect transplanted cells.

Authors

Christopher W. Peterson, Clarisse Benne, Patricia Polacino, Jasbir Kaur, Cristina E. McAllister, Abdelali Filali-Mouhim, Willi Obenza, Tiffany A. Pecor, Meei-Li Huang, Audrey Baldessari, Robert D. Murnane, Ann E. Woolfrey, Keith R. Jerome, Shiu-Lok Hu, Nichole R. Klatt, Stephen DeRosa, Rafick P. Sékaly, Hans-Peter Kiem

An early-biomarker algorithm predicts lethal graft-versus-host disease and survival

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Abstract

BACKGROUND. No laboratory test can predict the risk of nonrelapse mortality (NRM) or severe graft-versus-host disease (GVHD) after hematopoietic cellular transplantation (HCT) prior to the onset of GVHD symptoms.

METHODS. Patient blood samples on day 7 after HCT were obtained from a multicenter set of 1,287 patients, and 620 samples were assigned to a training set. We measured the concentrations of 4 GVHD biomarkers (ST2, REG3α, TNFR1, and IL-2Rα) and used them to model 6-month NRM using rigorous cross-validation strategies to identify the best algorithm that defined 2 distinct risk groups. We then applied the final algorithm in an independent test set (n = 309) and validation set (n = 358).

RESULTS. A 2-biomarker model using ST2 and REG3α concentrations identified patients with a cumulative incidence of 6-month NRM of 28% in the high-risk group and 7% in the low-risk group (P < 0.001). The algorithm performed equally well in the test set (33% vs. 7%, P < 0.001) and the multicenter validation set (26% vs. 10%, P < 0.001). Sixteen percent, 17%, and 20% of patients were at high risk in the training, test, and validation sets, respectively. GVHD-related mortality was greater in high-risk patients (18% vs. 4%, P < 0.001), as was severe gastrointestinal GVHD (17% vs. 8%, P < 0.001). The same algorithm can be successfully adapted to define 3 distinct risk groups at GVHD onset.

CONCLUSION. A biomarker algorithm based on a blood sample taken 7 days after HCT can consistently identify a group of patients at high risk for lethal GVHD and NRM.

FUNDING. The National Cancer Institute, American Cancer Society, and the Doris Duke Charitable Foundation.

Authors

Matthew J. Hartwell, Umut Özbek, Ernst Holler, Anne S. Renteria, Hannah Major-Monfried, Pavan Reddy, Mina Aziz, William J. Hogan, Francis Ayuk, Yvonne A. Efebera, Elizabeth O. Hexner, Udomsak Bunworasate, Muna Qayed, Rainer Ordemann, Matthias Wölfl, Stephan Mielke, Attaphol Pawarode, Yi-Bin Chen, Steven Devine, Andrew C. Harris, Madan Jagasia, Carrie L. Kitko, Mark R. Litzow, Nicolaus Kröger, Franco Locatelli, George Morales, Ryotaro Nakamura, Ran Reshef, Wolf Rösler, Daniela Weber, Kitsada Wudhikarn, Gregory A. Yanik, John E. Levine, James L.M. Ferrara

Transient antibody targeting of CD45RC induces transplant tolerance and potent antigen-specific regulatory T cells

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Abstract

Rat and human CD4⁺ and CD8⁺ Tregs expressing low levels of CD45RC have strong immunoregulatory properties. We describe here that human CD45 isoforms are nonredundant and identify distinct subsets of cells. We show that CD45RC is not expressed by CD4⁺ and CD8⁺ Foxp3⁺ Tregs, while CD45RA/RB/RO are. Transient administration of a monoclonal antibody (mAb) targeting CD45RC in a rat cardiac allotransplantation model induced transplant tolerance associated with inhibition of allogeneic humoral responses but maintained primary and memory responses against cognate antigens. Anti-CD45RC mAb induced rapid death of CD45RC^high T cells through intrinsic cell signaling but preserved and potentiated CD4⁺ and CD8⁺ CD45RC^low/– Tregs, which are able to adoptively transfer donor-specific tolerance to grafted recipients. Anti-CD45RC treatment results in distinct transcriptional signature of CD4⁺ and CD8⁺ CD45RC^low/– Tregs. Finally, we demonstrate that anti-human CD45RC treatment inhibited graft-versus-host disease (GVHD) in immune-humanized NSG mice. Thus, short-term anti-CD45RC is a potent therapeutic candidate to induce transplantation tolerance in human.

Authors

Elodie Picarda, Séverine Bézie, Laetitia Boucault, Elodie Autrusseau, Stéphanie Kilens, Dimitri Meistermann, Bernard Martinet, Véronique Daguin, Audrey Donnart, Eric Charpentier, Laurent David, Ignacio Anegon, Carole Guillonneau

Early cytokine signatures of ischemia/reperfusion injury in human orthotopic liver transplantation

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Abstract

BACKGROUND. Orthotopic liver transplant (OLT) is the primary therapy for end-stage liver disease and acute liver failure. However, ischemia/reperfusion injury (IRI) can severely compromise allograft survival. To understand the evolution of immune responses underlying OLT-IRI, we evaluated longitudinal cytokine expression profiles from adult OLT recipients before transplant through 1 month after transplant.

METHODS. We measured the expression of 38 cytokines, chemokines, and growth factors in preoperative and postoperative recipient circulating systemic blood (before transplant and 1 day, 1 week, and 1 month after transplant) and intraoperative portal blood (before and after reperfusion) of 53 OLT patients and analyzed this expression in relation to biopsy-proven IRI (n = 26 IRI+; 27 IRI–), clinical liver function tests early (days 1–7) after transplant, and expression of genes encoding cytokine receptors in biopsies of donor allograft taken before and after reperfusion.

RESULTS. Bilirubin and arginine transaminase levels early after transplant correlated with IRI. Fourteen cytokines were significantly increased in the systemic and/or portal blood of IRI+ recipients that shifted from innate to adaptive-immune responses over time. Additionally, expression of cognate receptors for 10 of these cytokines was detected in donor organ biopsies by RNAseq.

CONCLUSION. These results provide a mechanistic roadmap of the early immunological events both before and after IRI and suggest several candidates for patient stratification, monitoring, and treatment.

FUNDING. Ruth L. Kirschstein National Research Service Award T32CA009120, Keck Foundation award 986722, and a Quantitative & Computational Biosciences Collaboratory Postdoctoral Fellowship.

Authors

Rebecca A. Sosa, Ali Zarrinpar, Maura Rossetti, Charles R. Lassman, Bita V. Naini, Nakul Datta, Ping Rao, Nicholas Harre, Ying Zheng, Roberto Spreafico, Alexander Hoffmann, Ronald W. Busuttil, David W. Gjertson, Yuan Zhai, Jerzy W. Kupiec-Weglinski, Elaine F. Reed

Autophagy-dependent regulatory T cells are critical for the control of graft-versus-host disease

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Abstract

Regulatory T cells (Tregs) play a crucial role in the maintenance of peripheral tolerance. Quantitative and/or qualitative defects in Tregs result in diseases such as autoimmunity, allergy, malignancy, and graft-versus-host disease (GVHD), a serious complication of allogeneic stem cell transplantation (SCT). We recently reported increased expression of autophagy-related genes (Atg) in association with enhanced survival of Tregs after SCT. Autophagy is a self-degradative process for cytosolic components that promotes cell homeostasis and survival. Here, we demonstrate that the disruption of autophagy within FoxP3⁺ Tregs (B6.Atg7^fl/fl-FoxP3cre⁺) resulted in a profound loss of Tregs, particularly within the bone marrow (BM). This resulted in dysregulated effector T cell activation and expansion, and the development of enterocolitis and scleroderma in aged mice. We show that the BM compartment is highly enriched in TIGIT⁺ Tregs and that this subset is differentially depleted in the absence of autophagy. Moreover, following allogeneic SCT, recipients of grafts from B6.Atg7^fl/fl-FoxP3cre⁺ donors exhibited reduced Treg reconstitution, exacerbated GVHD, and reduced survival compared with recipients of B6.WT-FoxP3cre⁺ grafts. Collectively, these data indicate that autophagy-dependent Tregs are critical for the maintenance of tolerance after SCT and that the promotion of autophagy represents an attractive immune-restorative therapeutic strategy after allogeneic SCT.

Authors

Laëtitia Le Texier, Katie E. Lineburg, Benjamin Cao, Cameron McDonald-Hyman, Lucie Leveque-El Mouttie, Jemma Nicholls, Michelle Melino, Blessy C. Nalkurthi, Kylie A. Alexander, Bianca Teal, Stephen J. Blake, Fernando Souza-Fonseca-Guimaraes, Christian R. Engwerda, Rachel D. Kuns, Steven W. Lane, Michele Teng, Charis Teh, Daniel Gray, Andrew D. Clouston, Susan K. Nilsson, Bruce R. Blazar, Geoffrey R. Hill, Kelli P.A. MacDonald

Heart-resident CCR2⁺ macrophages promote neutrophil extravasation through TLR9/MyD88/CXCL5 signaling

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Abstract

It is well established that maladaptive innate immune responses to sterile tissue injury represent a fundamental mechanism of disease pathogenesis. In the context of cardiac ischemia reperfusion injury, neutrophils enter inflamed heart tissue, where they play an important role in potentiating tissue damage and contributing to contractile dysfunction. The precise mechanisms that govern how neutrophils are recruited to and enter the injured heart are incompletely understood. Using a model of cardiac transplant–mediated ischemia reperfusion injury and intravital 2-photon imaging of beating mouse hearts, we determined that tissue-resident CCR2⁺ monocyte–derived macrophages are essential mediators of neutrophil recruitment into ischemic myocardial tissue. Our studies revealed that neutrophil extravasation is mediated by a TLR9/MyD88/CXCL5 pathway. Intravital 2-photon imaging demonstrated that CXCL2 and CXCL5 play critical and nonredundant roles in guiding neutrophil adhesion and crawling, respectively. Together, these findings uncover a specific role for a tissue-resident monocyte-derived macrophage subset in sterile tissue inflammation and support the evolving concept that macrophage ontogeny is an important determinant of function. Furthermore, our results provide the framework for targeting of cell-specific signaling pathways in myocardial ischemia reperfusion injury.

Authors

Wenjun Li, Hsi-Min Hsiao, Ryuji Higashikubo, Brian T. Saunders, Ankit Bharat, Daniel R. Goldstein, Alexander S. Krupnick, Andrew E. Gelman, Kory J. Lavine, Daniel Kreisel

The MEK inhibitor trametinib separates murine graft-versus-host disease from graft-versus-tumor effects

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Abstract

The efficacy of allogeneic hematopoietic stem cell transplantation for hematologic malignancies is limited by the difficulty in suppressing graft-versus-host disease (GVHD) without compromising graft-versus-tumor (GVT) effects. We previously showed that RAS/MEK/ERK signaling depends on memory differentiation in human T cells, which confers susceptibility to selective inhibition of naive T cells. Actually, antineoplastic MEK inhibitors selectively suppress alloreactive T cells, sparing virus-specific T cells in vitro. Here, we show that trametinib, a MEK inhibitor clinically approved for melanoma, suppresses GVHD safely without affecting GVT effects in vivo. Trametinib prolonged survival of GVHD mice and attenuated GVHD symptoms and pathology in the gut and skin. It inhibited ERK1/2 phosphorylation and expansion of donor T cells, sparing Tregs and B cells. Although high-dose trametinib inhibited myeloid cell engraftment, low-dose trametinib suppressed GVHD without severe adverse events. Notably, trametinib facilitated the survival of mice transplanted with allogeneic T cells and P815 tumor cells with no residual P815 cells observed in the livers and spleens, whereas tacrolimus resulted in P815 expansion. These results confirm that trametinib selectively suppresses GVHD-inducing T cells while sparing antitumor T cells in vivo, which makes it a promising candidate for translational studies aimed at preventing or treating GVHD.

Authors

Hidekazu Itamura, Takero Shindo, Isao Tawara, Yasushi Kubota, Ryusho Kariya, Seiji Okada, Krishna V. Komanduri, Shinya Kimura

ISL1 cardiovascular progenitor cells for cardiac repair after myocardial infarction

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Abstract

Cardiovascular progenitor cells (CPCs) expressing the ISL1-LIM–homeodomain transcription factor contribute developmentally to cardiomyocytes in all 4 chambers of the heart. Here, we show that ISL1-CPCs can be applied to myocardial regeneration following injury. We used a rapid 3D methylcellulose approach to form murine and human ISL1-CPC spheroids that engrafted after myocardial infarction in murine hearts, where they differentiated into cardiomyocytes and endothelial cells, integrating into the myocardium and forming new blood vessels. ISL1-CPC spheroid–treated mice exhibited reduced infarct area and increased blood vessel formation compared with control animals. Moreover, left ventricular (LV) contractile function was significantly better in mice transplanted with ISL1-CPCs 4 weeks after injury than that in control animals. These results provide proof-of-concept of a cardiac repair strategy employing ISL1-CPCs that, based on our previous lineage-tracing studies, are committed to forming heart tissue, in combination with a robust methylcellulose spheroid–based delivery approach.

Authors

Oscar Bartulos, Zhen Wu Zhuang, Yan Huang, Nicole Mikush, Carol Suh, Alda Bregasi, Lin Wang, William Chang, Diane S. Krause, Lawrence H. Young, Jordan S. Pober, Yibing Qyang

Induced regulatory T cells in allograft tolerance via transient mixed chimerism

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Abstract

Successful induction of allograft tolerance has been achieved in nonhuman primates (NHPs) and humans via induction of transient hematopoietic chimerism. Since allograft tolerance was achieved in these recipients without durable chimerism, peripheral mechanisms are postulated to play a major role. Here, we report our studies of T cell immunity in NHP recipients that achieved long-term tolerance versus those that rejected the allograft (AR). All kidney, heart, and lung transplant recipients underwent simultaneous or delayed donor bone marrow transplantation (DBMT) following conditioning with a nonmyeloablative regimen. After DBMT, mixed lymphocyte culture with CFSE consistently revealed donor-specific loss of CD8⁺ T cell responses in tolerant (TOL) recipients, while marked CD4⁺ T cell proliferation in response to donor antigens was found to persist. Interestingly, a significant proportion of the proliferated CD4⁺ cells were FOXP3⁺ in TOL recipients, but not in AR or naive NHPs. In TOL recipients, CD4⁺FOXP3⁺ cell proliferation against donor antigens was greater than that observed against third-party antigens. Finally, the expanded Tregs appeared to be induced Tregs (iTregs) that were converted from non-Tregs. These data provide support for the hypothesis that specific induction of iTregs by donor antigens is key to long-term allograft tolerance induced by transient mixed chimerism.

Authors

Kiyohiko Hotta, Akihiro Aoyama, Tetsu Oura, Yohei Yamada, Makoto Tonsho, Kyu Ha Huh, Kento Kawai, David Schoenfeld, James S. Allan, Joren C. Madsen, Gilles Benichou, Rex-Neal Smith, Robert B. Colvin, David H. Sachs, A. Benedict Cosimi, Tatsuo Kawai