Damage to the gastrointestinal tract is a major cause of morbidity and mortality in graft-versus-host disease (GVHD) and is attributable to T cell–mediated inflammation. In this work, we identified a unique CD4+ T cell population that constitutively expresses the β2 integrin CD11c and displays a biased central memory phenotype and memory T cell transcriptional profile, innate-like properties, and increased expression of the gut-homing molecules α4β7 and CCR9. Using several complementary murine GVHD models, we determined that adoptive transfer and early accumulation of β2 integrin–expressing CD4+ T cells in the gastrointestinal tract initiated Th1-mediated proinflammatory cytokine production, augmented pathological damage in the colon, and increased mortality. The pathogenic effect of this CD4+ T cell population critically depended on coexpression of the IL-23 receptor, which was required for maximal inflammatory effects. Non–Foxp3-expressing CD4+ T cells produced IL-10, which regulated colonic inflammation and attenuated lethality in the absence of functional CD4+Foxp3+ T cells. Thus, the coordinate expression of CD11c and the IL-23 receptor defines an IL-10–regulated, colitogenic memory CD4+ T cell subset that is poised to initiate inflammation when there is loss of tolerance and breakdown of mucosal barriers.
Vivian Zhou, Kimberle Agle, Xiao Chen, Amy Beres, Richard Komorowski, Ludovic Belle, Carolyn Taylor, Fenlu Zhu, Dipica Haribhai, Calvin B. Williams, James Verbsky, Wendy Blumenschein, Svetlana Sadekova, Eddie Bowman, Christie Ballantyne, Casey Weaver, David A. Serody, Benjamin Vincent, Jonathan Serody, Daniel J. Cua, William R. Drobyski
The immune response against transplanted allografts is one of the most potent reactions mounted by the immune system. The acute rejection response has been attributed to donor dendritic cells (DCs), which migrate to recipient lymphoid tissues and directly activate alloreactive T cells against donor MHC molecules. Here, using a murine heart transplant model, we determined that only a small number of donor DCs reach lymphoid tissues and investigated how this limited population of donor DCs efficiently initiates the alloreactive T cell response that causes acute rejection. In our mouse model, efficient passage of donor MHC molecules to recipient conventional DCs (cDCs) was dependent on the transfer of extracellular vesicles (EVs) from donor DCs that migrated from the graft to lymphoid tissues. These EVs shared characteristics with exosomes and were internalized or remained attached to the recipient cDCs. Recipient cDCs that acquired exosomes became activated and triggered full activation of alloreactive T cells. Depletion of recipient cDCs after cardiac transplantation drastically decreased presentation of donor MHC molecules to directly alloreactive T cells and delayed graft rejection in mice. These findings support a key role for transfer of donor EVs in the generation of allograft-targeting immune responses and suggest that interrupting this process has potential to dampen the immune response to allografts.
Quan Liu, Darling M. Rojas-Canales, Sherrie J. Divito, William J. Shufesky, Donna Beer Stolz, Geza Erdos, Mara L.G. Sullivan, Gregory A. Gibson, Simon C. Watkins, Adriana T. Larregina, Adrian E. Morelli
Transplantation is the only cure for end-stage organ failure, but without immunosuppression, T cells rapidly reject allografts. While genetic disparities between donor and recipient are major determinants of the kinetics of transplant rejection, little is known about the contribution of environmental factors. Because colonized organs have worse transplant outcome than sterile organs, we tested the influence of host and donor microbiota on skin transplant rejection. Compared with untreated conventional mice, pretreatment of donors and recipients with broad-spectrum antibiotics (Abx) or use of germ-free (GF) donors and recipients resulted in prolonged survival of minor antigen–mismatched skin grafts. Increased graft survival correlated with reduced type I IFN signaling in antigen-presenting cells (APCs) and decreased priming of alloreactive T cells. Colonization of GF mice with fecal material from untreated conventional mice, but not from Abx-pretreated mice, enhanced the ability of APCs to prime alloreactive T cells and accelerated graft rejection, suggesting that alloimmunity is modulated by the composition of microbiota rather than the quantity of bacteria. Abx pretreatment of conventional mice also delayed rejection of major antigen–mismatched skin and MHC class II–mismatched cardiac allografts. This study demonstrates that Abx pretreatment prolongs graft survival, suggesting that targeting microbial constituents is a potential therapeutic strategy for enhancing graft acceptance.
Yuk Man Lei, Luqiu Chen, Ying Wang, Andrew T. Stefka, Luciana L. Molinero, Betty Theriault, Keston Aquino-Michaels, Ayelet S. Sivan, Cathryn R. Nagler, Thomas F. Gajewski, Anita S. Chong, Caroline Bartman, Maria-Luisa Alegre
Programmed death ligand-1 (PD-L1) interaction with PD-1 induces T cell exhaustion and is a therapeutic target to enhance immune responses against cancer and chronic infections. In murine bone marrow transplant models, PD-L1 expression on host target tissues reduces the incidence of graft-versus-host disease (GVHD). PD-L1 is also expressed on T cells; however, it is unclear whether PD-L1 on this population influences immune function. Here, we examined the effects of PD-L1 modulation of T cell function in GVHD. In patients with severe GVHD, PD-L1 expression was increased on donor T cells. Compared with mice that received WT T cells, GVHD was reduced in animals that received T cells from
Asim Saha, Roddy S. O’Connor, Govindarajan Thangavelu, Scott B. Lovitch, Durga Bhavani Dandamudi, Caleph B. Wilson, Benjamin G. Vincent, Victor Tkachev, Jan M. Pawlicki, Scott N. Furlan, Leslie S. Kean, Kazutoshi Aoyama, Patricia A. Taylor, Angela Panoskaltsis-Mortari, Rocio Foncea, Parvathi Ranganathan, Steven M. Devine, Joel S. Burrill, Lili Guo, Catarina Sacristan, Nathaniel W. Snyder, Ian A. Blair, Michael C. Milone, Michael L. Dustin, James L. Riley, David A. Bernlohr, William J. Murphy, Brian T. Fife, David H. Munn, Jeffrey S. Miller, Jonathan S. Serody, Gordon J. Freeman, Arlene H. Sharpe, Laurence A. Turka, Bruce R. Blazar
Experimentally, females show an improved ability to recover from ischemia-reperfusion injury (IRI) compared with males; however, this sex-dependent response is less established in humans. Here, we developed a series of murine renal ischemia and transplant models to investigate sex-specific effects on recovery after IRI. We found that IRI tolerance is profoundly increased in female mice compared with that observed in male mice and discovered an intermediate phenotype after neutering of either sex. Transplantation of adult kidneys from either sex into a recipient of the opposite sex followed by ischemia at a remote time resulted in ischemia recovery that reflected the sex of the recipient, not the donor, revealing that the host sex determines recovery. Likewise, renal IRI was exacerbated in female estrogen receptor α–KO mice, while female mice receiving supplemental estrogen before ischemia were protected. We examined data from the United Network for Organ Sharing (UNOS) to determine whether there is an association between sex and delayed graft function (DGF) in patients who received deceased donor renal transplants. A multivariable logistic regression analysis determined that there was a greater association with DGF in male recipients than in female recipients. Together, our results demonstrate that sex affects renal IRI tolerance in mice and humans and indicate that estrogen administration has potential as a therapeutic intervention to clinically improve ischemia tolerance.
David D. Aufhauser Jr., Zhonglin Wang, Douglas R. Murken, Tricia R. Bhatti, Yanfeng Wang, Guanghui Ge, Robert R. Redfield III, Peter L. Abt, Liqing Wang, Nikolaos Svoronos, Arwin Thomasson, Peter P. Reese, Wayne W. Hancock, Matthew H. Levine
Adoptive immunotherapy with regulatory T cells (Tregs) is a promising treatment for allograft rejection and graft-versus-host disease (GVHD). Emerging data indicate that, compared with polyclonal Tregs, disease-relevant antigen-specific Tregs may have numerous advantages, such as a need for fewer cells and reduced risk of nonspecific immune suppression. Current methods to generate alloantigen-specific Tregs rely on expansion with allogeneic antigen-presenting cells, which requires access to donor and recipient cells and multiple MHC mismatches. The successful use of chimeric antigen receptors (CARs) for the generation of antigen-specific effector T cells suggests that a similar approach could be used to generate alloantigen-specific Tregs. Here, we have described the creation of an HLA-A2–specific CAR (A2-CAR) and its application in the generation of alloantigen-specific human Tregs. In vitro, A2-CAR–expressing Tregs maintained their expected phenotype and suppressive function before, during, and after A2-CAR–mediated stimulation. In mouse models, human A2-CAR–expressing Tregs were superior to Tregs expressing an irrelevant CAR at preventing xenogeneic GVHD caused by HLA-A2+ T cells. Together, our results demonstrate that use of CAR technology to generate potent, functional, and stable alloantigen-specific human Tregs markedly enhances their therapeutic potential in transplantation and sets the stage for using this approach for making antigen-specific Tregs for therapy of multiple diseases.
Katherine G. MacDonald, Romy E. Hoeppli, Qing Huang, Jana Gillies, Dan S. Luciani, Paul C. Orban, Raewyn Broady, Megan K. Levings
Grégoire Couvrat-Desvergnes, Apolline Salama, Ludmilla Le Berre, Gwénaëlle Evanno, Ondrej Viklicky, Petra Hruba, Pavel Vesely, Pierrick Guerif, Thomas Dejoie, Juliette Rousse, Arnaud Nicot, Jean-Marie Bach, Evelyn Ang, Yohann Foucher, Sophie Brouard, Stéphanie Castagnet, Magali Giral, Jean Harb, Hélène Perreault, Béatrice Charreau, Marine Lorent, Jean-Paul Soulillou
Lung transplantation is the only viable option for patients suffering from otherwise incurable end-stage pulmonary diseases such as chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis. Despite aggressive immunosuppression, acute rejection of the lung allograft occurs in over half of transplant recipients, and the factors that promote lung acceptance are poorly understood. The contribution of lymphatic vessels to transplant pathophysiology remains controversial, and data that directly address the exact roles of lymphatic vessels in lung allograft function and survival are limited. Here, we have shown that there is a marked decline in the density of lymphatic vessels, accompanied by accumulation of low-MW hyaluronan (HA) in mouse orthotopic allografts undergoing rejection. We found that stimulation of lymphangiogenesis with VEGF-C156S, a mutant form of VEGF-C with selective VEGFR-3 binding, alleviates an established rejection response and improves clearance of HA from the lung allograft. Longitudinal analysis of transbronchial biopsies from human lung transplant recipients demonstrated an association between resolution of acute lung rejection and decreased HA in the graft tissue. Taken together, these results indicate that lymphatic vessel formation after lung transplantation mediates HA drainage and suggest that treatments to stimulate lymphangiogenesis have promise for improving graft outcomes.
Ye Cui, Kaifeng Liu, Maria E. Monzon-Medina, Robert F. Padera, Hao Wang, Gautam George, Demet Toprak, Elie Abdelnour, Emmanuel D’Agostino, Hilary J. Goldberg, Mark A. Perrella, Rosanna Malbran Forteza, Ivan O. Rosas, Gary Visner, Souheil El-Chemaly
Cytokines and metabolic pathway–controlling enzymes regulate immune responses and have potential as powerful tools to mediate immune tolerance. Blockade of the interaction between CD40 and CD40L induces long-term cardiac allograft survival in rats through a CD8+CD45RClo Treg potentiation. Here, we have shown that the cytokine IL-34, the immunoregulatory properties of which have not been previously studied in transplantation or T cell biology, is expressed by rodent CD8+CD45RClo Tregs and human FOXP3+CD45RCloCD8+ and CD4+ Tregs. IL-34 was involved in the suppressive function of both CD8+ and CD4+ Tregs and markedly inhibited alloreactive immune responses. Additionally, in a rat cardiac allograft model, IL-34 potently induced transplant tolerance that was associated with a total inhibition of alloantibody production. Treatment of rats with IL-34 promoted allograft tolerance that was mediated by induction of CD8+ and CD4+ Tregs. Moreover, these Tregs were capable of serial tolerance induction through modulation of macrophages that migrate early to the graft. Finally, we demonstrated that human macrophages cultured in the presence of IL-34 greatly expanded CD8+ and CD4+ FOXP3+ Tregs, with a superior suppressive potential of antidonor immune responses compared with non–IL-34–expanded Tregs. In conclusion, we reveal that IL-34 serves as a suppressive Treg–specific cytokine and as a tolerogenic cytokine that efficiently inhibits alloreactive immune responses and mediates transplant tolerance.
Séverine Bézie, Elodie Picarda, Jason Ossart, Laurent Tesson, Claire Usal, Karine Renaudin, Ignacio Anegon, Carole Guillonneau
Marie Bleakley, Shelly Heimfeld, Keith R. Loeb, Lori A. Jones, Colette Chaney, Stuart Seropian, Ted A. Gooley, Franziska Sommermeyer, Stanley R. Riddell, Warren D. Shlomchik
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