Regulatory T-cells (Treg) are critical for maintaining immune homeostasis. However, current Treg immunotherapies do not optimally treat inflammatory diseases in patients. Understanding the cellular processes that control Treg function may allow for the augmentation of therapeutic efficacy. In contrast to activated conventional T-cells, where protein kinase C-θ (PKC-θ) localizes to the contact-point between T-cells and antigen-presenting cells, in human and mouse Treg, PKC-θ localizes to the opposite end of the cell in the distal pole complex (DPC). Here, using a phosphoproteomic screen, we identified the intermediate filament vimentin as a PKC-θ phospho-target and show that vimentin forms a DPC superstructure on which PKC-θ accumulates. Treatment of mouse Treg with either a clinically relevant PKC-θ inhibitor or vimentin siRNA disrupted vimentin and enhanced Treg metabolic and suppressive activity. Moreover, vimentin-disrupted mouse Treg were significantly better than controls in suppressing alloreactive T-cell priming in graft-versus-host disease, and graft-versus-host disease lethality, using a complete MHC mismatch mouse model of acute graft-versus-host disease (C57BL/6 donor in to BALB/c host). Interestingly, vimentin disruption augmented suppressor function of PKC-θ-deficient mouse Treg. This suggests that enhanced Treg activity after PKC-θ inhibition is secondary to effects on vimentin, not just PKC-θ kinase activity inhibition. Our data demonstrated that vimentin is a key metabolic and functional controller of Treg activity, and provide proof-of-principle that disrupting vimentin is a feasible, translationally relevant method to enhance Treg potency.
Cameron McDonald-Hyman, James T. Muller, Michael Loschi, Govindarajan Thangavelu, Asim Saha, Sudha Kumari, Dawn K. Reichenbach, Michelle J. Smith, Guoan Zhang, Brent H. Koehn, Jiqiang Lin, Jason S. Mitchell, Brian T. Fife, Angela Panoskaltsis-Mortari, Colby J. Feser, Andrew Kemal Kirchmeier, Mark J. Osborn, Keli L. Hippen, Ameeta Kelekar, Jonathan S. Serody, Laurence A. Turka, David H. Munn, Hongbo Chi, Thomas A. Neubert, Michael L. Dustin, Bruce R. Blazar
Graft-versus-host disease (GVHD) in the gastrointestinal (GI) tract remains the major cause of morbidity and non-relapse mortality after bone marrow transplantation (BMT). The Paneth cell protein, regenerating islet-derived 3-alpha (REG3α), is a biomarker specific for GI GVHD. REG3α serum levels rose in the systematic circulation as GVHD progressively destroyed Paneth cells and reduced GI epithelial barrier function. Paradoxically, GVHD suppressed intestinal REG3γ (the mouse homologue of human REG3α), and the absence of REG3γ in BMT recipients intensified GVHD but did not change the composition of the microbiome. IL-22 administration restored REG3γ production and prevented apoptosis of both intestinal stem cells (ISCs) and Paneth cells, but this protection was completely abrogated in Reg3g−/− mice. In vitro, addition of REG3α reduced the apoptosis of colonic cell lines. Strategies that increase intestinal REG3α/γ to promote crypt regeneration may offer a novel, non-immunosuppressive approach for GVHD and perhaps for other diseases involving the ISC niche such as inflammatory bowel disease.
Dongchang Zhao, Yeung-Hyen Kim, Seihwan Jeong, Joel K. Greenson, Mohammed S. Chaudhry, Matthias Hoepting, Erik R. Anderson, Marcel R.M. van den Brink, Jonathan U. Peled, Antonio L.C. Gomes, Ann E. Slingerland, Michael J. Donovan, Andrew C. Harris, John E. Levine, Umut Özbek, Lora V. Hooper, Thaddeus S. Stappenbeck, Aaron M. Ver Heul, Ta-Chiang Liu, Pavan Reddy, James L.M. Ferrara
Controlling graft-versus-host disease (GVHD) remains a major unmet need in stem cell transplantation, and new, targeted therapies are being actively developed. CD28-CD80/86 costimulation blockade represents a promising strategy, but targeting CD80/CD86 with CTLA4-Ig may be associated with undesired blockade of coinhibitory pathways. In contrast, targeted blockade of CD28 exclusively inhibits T cell costimulation and may more potently prevent GVHD. Here, we investigated FR104, an antagonistic CD28-specific pegylated-Fab′, in the nonhuman primate (NHP) GVHD model and completed a multiparameter interrogation comparing it with CTLA4-Ig, with and without sirolimus, including clinical, histopathologic, flow cytometric, and transcriptomic analyses. We document that FR104 monoprophylaxis and combined prophylaxis with FR104/sirolimus led to enhanced control of effector T cell proliferation and activation compared with the use of CTLA4-Ig or CTLA4-Ig/sirolimus. Importantly, FR104/sirolimus did not lead to a beneficial impact on Treg reconstitution or homeostasis, consistent with control of conventional T cell activation and IL-2 production needed to support Tregs. While FR104/sirolimus had a salutary effect on GVHD-free survival, overall survival was not improved, due to death in the absence of GVHD in several FR104/sirolimus recipients in the setting of sepsis and a paralyzed INF-γ response. These results therefore suggest that effectively deploying CD28 in the clinic will require close scrutiny of both the benefits and risks of extensively abrogating conventional T cell activation after transplant.
Benjamin K. Watkins, Victor Tkachev, Scott N. Furlan, Daniel J. Hunt, Kayla Betz, Alison Yu, Melanie Brown, Nicolas Poirier, Hengqi Betty Zheng, Agne Taraseviciute, Lucrezia Colonna, Caroline Mary, Gilles Blancho, Jean-Paul Soulillou, Angela Panoskaltsis-Mortari, Prachi Sharma, Anapatricia Garcia, Elizabeth Strobert, Kelly Hamby, Aneesah Garrett, Taylor Deane, Bruce R. Blazar, Bernard Vanhove, Leslie S. Kean
Purinergic receptor-7 (P2X7R) signaling controls Th17 and Th1 generation/differentiation, while NOD-like receptor P3 (NLRP3) acts as a Th2 transcriptional factor. Here, we demonstrated the existence of a P2X7R/NLRP3 pathway in T cells that is dysregulated by a P2X7R intracellular region loss-of-function mutation, leading to NLRP3 displacement and to excessive Th17 generation due to abrogation of the NLRP3-mediated Th2 program. This ultimately resulted in poor outcomes in cardiac-transplanted patients carrying the mutant allele, who showed abnormal Th17 generation. Transient NLRP3 silencing in nonmutant T cells or overexpression in mutant T cells normalized the Th profile. Interestingly, IL-17 blockade reduced Th17 skewing of human T cells in vitro and abrogated the severe allograft vasculopathy and abnormal Th17 generation observed in preclinical models in which P2X7R was genetically deleted. This P2X7R intracellular region mutation thus impaired the modulatory effects of P2X7R on NLRP3 expression and function in T cells and led to NLRP3 dysregulation and Th17 skewing, delineating a high-risk group of cardiac-transplanted patients who may benefit from personalized therapy.
Francesca D’Addio, Andrea Vergani, Luciano Potena, Anna Maestroni, Vera Usuelli, Moufida Ben Nasr, Roberto Bassi, Sara Tezza, Sergio Dellepiane, Basset El Essawy, Maria Iascone, Attilio Iacovoni, Laura Borgese, Kaifeng Liu, Gary Visner, Sirano Dhe-Paganon, Domenico Corradi, Reza Abdi, Randall C. Starling, Franco Folli, Gian Vincenzo Zuccotti, Mohamed H. Sayegh, Peter S. Heeger, Anil Chandraker, Francesco Grigioni, Paolo Fiorina
T cells must migrate in order to encounter antigen-presenting cells (APCs) and to execute their varied functions in immune defense and inflammation. ATP release and autocrine signaling through purinergic receptors contribute to T cell activation at the immune synapse that T cells form with APCs. Here, we show that T cells also require ATP release and purinergic signaling for their migration to APCs. We found that the chemokine SDF-1α triggered mitochondrial ATP production, rapid bursts of ATP release, and increased migration of primary human CD4+ T cells. This process depended on pannexin-1 ATP release channels and autocrine stimulation of P2X4 receptors. SDF-1α stimulation caused localized accumulation of mitochondria with P2X4 receptors near the front of cells, resulting in a feed-forward signaling mechanism that promotes cellular Ca2+ influx and sustains mitochondrial ATP synthesis at levels needed for pseudopod protrusion, T cell polarization, and cell migration. Inhibition of P2X4 receptors blocked the activation and migration of T cells in vitro. In a mouse lung transplant model, P2X4 receptor antagonist treatment prevented the recruitment of T cells into allograft tissue and the rejection of lung transplants. Our findings suggest that P2X4 receptors are therapeutic targets for immunomodulation in transplantation and inflammatory diseases.
Carola Ledderose, Kaifeng Liu, Yutaka Kondo, Christian J. Slubowski, Thomas Dertnig, Sara Denicoló, Mona Arbab, Johannes Hubner, Kirstin Konrad, Mahtab Fakhari, James A. Lederer, Simon C. Robson, Gary A. Visner, Wolfgang G. Junger
Ischemia-reperfusion injury, a form of sterile inflammation, is the leading risk factor for both short-term mortality following pulmonary transplantation and chronic lung allograft dysfunction. While it is well recognized that neutrophils are critical mediators of acute lung injury, processes that guide their entry into pulmonary tissue are not well understood. Here, we found that CCR2+ classical monocytes are necessary and sufficient for mediating extravasation of neutrophils into pulmonary tissue during ischemia-reperfusion injury following hilar clamping or lung transplantation. The classical monocytes were mobilized from the host spleen, and splenectomy attenuated the recruitment of classical monocytes as well as the entry of neutrophils into injured lung tissue, which was associated with improved graft function. Neutrophil extravasation was mediated by MyD88-dependent IL-1β production by graft-infiltrating classical monocytes, which downregulated the expression of the tight junction–associated protein ZO-2 in pulmonary vascular endothelial cells. Thus, we have uncovered a crucial role for classical monocytes, mobilized from the spleen, in mediating neutrophil extravasation, with potential implications for targeting of recipient classical monocytes to ameliorate pulmonary ischemia-reperfusion injury in the clinic.
Hsi-Min Hsiao, Ramiro Fernandez, Satona Tanaka, Wenjun Li, Jessica H. Spahn, Stephen Chiu, Mahzad Akbarpour, Daniel Ruiz-Perez, Qiang Wu, Cem Turam, Davide Scozzi, Tsuyoshi Takahashi, Hannah P. Luehmann, Varun Puri, G.R. Scott Budinger, Alexander S. Krupnick, Alexander V. Misharin, Kory J. Lavine, Yongjian Liu, Andrew E. Gelman, Ankit Bharat, Daniel Kreisel
PIM kinase family members play a crucial role in promoting cell survival and proliferation via phosphorylation of their target substrates. In this study, we investigated the role of the PIM kinases with respect to T cell responses in transplantation and tumor immunity. We found that the PIM-2 isoform negatively regulated T cell responses to alloantigen, in contrast to the PIM-1 and PIM-3 isoforms, which acted as positive regulators. T cells deficient in PIM-2 demonstrated increased T cell differentiation toward Th1 subset, proliferation, and migration to target organs after allogeneic bone marrow transplantation, resulting in dramatically accelerated graft-versus-host disease (GVHD) severity. Restoration of PIM-2 expression markedly attenuated the pathogenicity of PIM-2–deficient T cells to induce GVHD. On the other hand, mice deficient in PIM-2 readily rejected syngeneic tumor, which was primarily dependent on CD8+ T cells. Furthermore, silencing PIM-2 in polyclonal or antigen-specific CD8+ T cells substantially enhanced their antitumor response in adoptive T cell immunotherapy. We conclude that PIM-2 kinase plays a prominent role in suppressing T cell responses, and provide a strong rationale to target PIM-2 for cancer immunotherapy.
Anusara Daenthanasanmak, Yongxia Wu, Supinya Iamsawat, Hung D. Nguyen, David Bastian, MengMeng Zhang, M. Hanief Sofi, Shilpak Chatterjee, Elizabeth G. Hill, Shikhar Mehrotra, Andrew S. Kraft, Xue-Zhong Yu
Mucosal-associated invariant T (MAIT) cells are a unique innate-like T cell subset that responds to a wide array of bacteria and yeast through recognition of riboflavin metabolites presented by the MHC class I–like molecule MR1. Here, we demonstrate using MR1 tetramers that recipient MAIT cells are present in small but definable numbers in graft-versus-host disease (GVHD) target organs and protect from acute GVHD in the colon following bone marrow transplantation (BMT). Consistent with their preferential juxtaposition to microbial signals in the colon, recipient MAIT cells generate large amounts of IL-17A, promote gastrointestinal tract integrity, and limit the donor alloantigen presentation that in turn drives donor Th1 and Th17 expansion specifically in the colon after BMT. Allogeneic BMT recipients deficient in IL-17A also develop accelerated GVHD, suggesting MAIT cells likely regulate GVHD, at least in part, by the generation of this cytokine. Indeed, analysis of stool microbiota and colon tissue from IL-17A–/– and MR1–/– mice identified analogous shifts in microbiome operational taxonomic units (OTU) and mediators of barrier integrity that appear to represent pathways controlled by similar, IL-17A–dependent mechanisms. Thus, MAIT cells act to control barrier function to attenuate pathogenic T cell responses in the colon and, given their very high frequency in humans, likely represent an important population in clinical BMT.
Antiopi Varelias, Mark D. Bunting, Kate L. Ormerod, Motoko Koyama, Stuart D. Olver, Jasmin Straube, Rachel D. Kuns, Renee J. Robb, Andrea S. Henden, Leanne Cooper, Nancy Lachner, Kate H. Gartlan, Olivier Lantz, Lars Kjer-Nielsen, Jeffrey Y.W. Mak, David P. Fairlie, Andrew D. Clouston, James McCluskey, Jamie Rossjohn, Steven W. Lane, Philip Hugenholtz, Geoffrey R. Hill
Transplantation of neural progenitor cells (NPCs) is a potential therapy for treating neurodegenerative disorders, but this approach has faced many challenges and limited success, primarily because of inhospitable host brain environments that interfere with enriched neuron engraftment and function. Astrocytes play neurotrophic roles in the developing and adult brain, making them potential candidates for helping with modification of hostile brain environments. In this study, we examined whether astrocytic function could be utilized to overcome the current limitations of cell-based therapies in a murine model of Parkinson’s disease (PD) that is characterized by dopamine (DA) neuron degeneration in the midbrain. We show here that cografting astrocytes, especially those derived from the midbrain, remarkably enhanced NPC-based cell therapeutic outcomes along with robust DA neuron engraftment in PD rats for at least 6 months after transplantation. We further show that engineering of donor astrocytes with Nurr1 and Foxa2, transcription factors that were recently reported to polarize harmful immunogenic glia into the neuroprotective form, further promoted the neurotrophic actions of grafted astrocytes in the cell therapeutic approach. Collectively, these findings suggest that cografting astrocytes could be a potential strategy for successful cell therapeutic outcomes in neurodegenerative disorders.
Jae-Jin Song, Sang-Min Oh, Oh-Chan Kwon, Noviana Wulnansari, Hyun-Seob Lee, Mi-Yoon Chang, Eunsoo Lee, Woong Sun, Sang-Eun Lee, Sunghoe Chang, Heeyoung An, C. Justin Lee, Sang-Hun Lee
Humoral rejection is the most common cause of solid organ transplant failure. Here, we evaluated a cohort of 49 patients who were successfully grafted with allogenic islets and determined that the appearance of donor-specific anti-HLA antibodies (DSAs) did not accelerate the rate of islet graft attrition, suggesting resistance to humoral rejection. Murine DSAs bound to allogeneic targets expressed by islet cells and induced their destruction in vitro; however, passive transfer of the same DSAs did not affect islet graft survival in murine models. Live imaging revealed that DSAs were sequestrated in the circulation of the recipients and failed to reach the endocrine cells of grafted islets. We used murine heart transplantation models to confirm that endothelial cells were the only accessible targets for DSAs, which induced the development of typical microvascular lesions in allogeneic transplants. In contrast, the vasculature of DSA-exposed allogeneic islet grafts was devoid of lesions because sprouting of recipient capillaries reestablished blood flow in grafted islets. Thus, we conclude that endothelial chimerism combined with vascular sequestration of DSAs protects islet grafts from humoral rejection. The reduced immunoglobulin concentrations in the interstitial tissue, confirmed in patients, may have important implications for biotherapies such as vaccines and monoclonal antibodies.
Chien-Chia Chen, Eric Pouliquen, Alexis Broisat, Francesco Andreata, Maud Racapé, Patrick Bruneval, Laurence Kessler, Mitra Ahmadi, Sandrine Bacot, Carole Saison-Delaplace, Marina Marcaud, Jean-Paul Duong Van Huyen, Alexandre Loupy, Jean Villard, Sandrine Demuylder-Mischler, Thierry Berney, Emmanuel Morelon, Meng-Kun Tsai, Marie-Nathalie Kolopp-Sarda, Alice Koenig, Virginie Mathias, Stéphanie Ducreux, Catherine Ghezzi, Valerie Dubois, Antonino Nicoletti, Thierry Defrance, Olivier Thaunat
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