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Vers la fin du XIXe siecle, au commencement de la modernisation du Japon, on assiste a l’emergence d’une serie d’idees et de raisonnements feministes. Les recherches dans ce domaine sont relativement developpees en histoire et en sociologie, mais elles ont ete negligees du point de vue de la philosophie. Cet article vise donc a combler cette lacune en mettant en relief les « reflexions sur le genre » menees par les penseurs des siecles passes, notamment en s’interessant a la question de la « dignite » de la femme comme concept clef. A l’epoque, « dignite » etait un mot nouveau absent du vocabulaire scientifique ou journalistique. Ainsi, a partir de l’hypothese que l’origine du feminisme s’est accompagnee d’une prise de conscience concernant la « dignite », nous examinons les discours des penseurs hommes qui ont defendu et œuvre a l’education des femmes, de meme que les discours des femmes qui ont participe aux activites intellectuelles et ont defendu l’emancipation feminine.

Lymph nodes (LNs) are the critical sites of immunity, and the stromal cells of LNs are crucial to their function. Our understanding of the stromal compartment of the LN has deepened recently with the characterization of nontraditional stromal cells. CD41 (integrin αIIb) is known to be expressed by platelets and hematolymphoid cells. We identified two distinct populations of CD41

Heart transplantation is the optimal therapy for patients with end-stage heart disease, but its long-term outcome remains inadequate. Recent studies have highlighted the importance of the melanocortin receptors (MCRs) in inflammation, but how MCRs regulate the balance between alloreactive T cells and Tregs, and whether they impact chronic heart transplant rejection, is unknown. Here, we found that Tregs express MC2R, and MC2R expression was highest among all MCRs by Tregs. Our data indicate that adrenocorticotropic hormone (ACTH), the sole ligand for MC2R, promoted the formation of Tregs by increasing the expression of IL-2Rα (CD25) in CD4+ T cells and activation of STAT5 in CD4+CD25+ T cells. ACTH treatment also improved the survival of heart allografts and increased the formation of Tregs in CD28KO mice. ACTH treatment synergized with the tolerogenic effect of CTLA-4-Ig, resulting in long-term survival of heart allografts and an increase in intragraft Tregs. ACTH administration also demonstrated higher prolongation of heart allograft survival in transgenic mouse recipients with both complete KO and conditional KO of PI3Kγ in T cells. Finally, ACTH treatment reduced chronic rejection markedly. These data demonstrate that ACTH treatment improved heart transplant outcomes, and this effect correlated with an increase in Tregs.

Inflammation occurring within the transplanted organ from the time of harvest is an important stimulus of early alloimmune reactivity, and promotes chronic allograft rejection. Chronic immune-mediated injury remains the primary obstacle to the long-term success of organ transplantation. However, organ transplantation represents a rare clinical setting in which the organ is accessible ex vivo, providing a unique opportunity to use nanotechnology to directly deliver therapeutics to the graft. This approach facilitates the directed delivery of immunosuppressive agents (ISA) to locally target pathogenic immune responses prior to the transplantation. Here, we have developed a system of direct delivery and sustained release of mycophenolate mofetil (MMF), to treat the donor organ prior to transplantation. Perfusion of a donor mouse heart with MMF-loaded PEG-PLGA nanoparticles (MMF-NP) prior to transplantation abrogated chronic allograft rejection by suppressing intra-graft pro-inflammatory cytokines and chemokines. Our findings demonstrate that ex vivo delivery of an ISA to donor organs using a nanocarrier can serve as a clinically feasible approach to reduce chronic allograft rejection.

The pancreatic lymph node is critical to the pathogenesis of autoimmune diabetes, as it constitutes the initial site for the priming of autoreactive T cells. In this study, we compared the histopathology of the head pancreatic lymph node (HPLN) to the tail pancreatic lymph node (TPLN) in NOD mice. HPLNs and TPLNs were harvested from 4 week-, 8 week-, and 12 week-old NOD mice, and their microvasculature, extracellular matrix, and immune cell subsets were characterized. The percentages of B cells and antigen-presenting cells (APCs) were much higher in the HPLN, as compared to the TPLN. Notably, the HPLNs of 12 week-old mice were characterized by greater expansion of high endothelial venules (HEVs) and lymphatic vessels in comparison to the TPLNs. Finally, we observed a higher density of extracellular matrix (ECM) fibers surrounding the lymphatic vasculature in the HPLNs than in the TPLNs. These data for the first time demonstrate that the HPLN possesses a different immune microanatomy and organization from the TPLN. These novel observations unveil a major phenotypic difference between two types of LNs from the same organ and may highlight an independent fundamental role played by each PLN during the establishment of T1D.

Ischemia-reperfusion injury represents one of the most common causes of acute kidney injury, a serious and often deadly condition that affects up to 20% of all hospitalized patients in the United States. However, the current standard assay used universally for the diagnosis of acute kidney injury, serum creatinine, does not detect renal damage early in its course. Serendipitously, we found that the immunofluorescent signal of the constitutive podocyte marker podoplanin fades in the glomerulus and intensifies in the tubulointerstitial compartment of the kidney shortly after ischemia-reperfusion injury in 8- to 10-wk-old male C57Bl/6j mice. Therefore, we sought to define the appearance and course of the podoplanin-positive signal in the kidney after ischemia-reperfusion injury. The tubulointerstitial podoplanin-positive signal increased as early as 2 h but persisted for 7 days after ischemia-reperfusion injury. In addition, the strength of this tubulointerstitial signal was directly proportional to the severity of ischemia, and its location shifted from the tubules to interstitial cells over time. Finally, we detected podoplanin in the urine of mice after ischemia, and we observed that an increase in the urine podoplanin-to-creatinine ratio correlated strongly with the onset of renal ischemia-reperfusion injury. Our findings indicate that the measurement of urine podoplanin harbors promising potential for use as a novel biomarker for the early detection of ischemia-reperfusion injury of the kidney.

Costimulation is a critical step in T-cell activation, and costimulatory blockade at the time of T cell activation leads to T-cell anergy and allograft tolerance in animal models of transplantation. CD28:B7 is the most important costimulatory pathway and the balance of signals between CD28 and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) is a central determinant of transplant outcome. Form a clinical standpoint, CTLA-4 Ig is the only approved agent for costimulation blockade in transplantation. Advantages and disadvantages of its use are discussed. Progress in developing novel agents to target other pathways, including the promising CD40:CD154 pathway, is also discussed.

Despite much progress in improving graft outcome during cardiac transplantation, chronic allograft vasculopathy (CAV) remains an impediment to long‐term graft survival. MicroRNAs (miRNAs) emerged as regulators of the immune response. Here, we aimed to examine the miRNA network involved in CAV. miRNA profiling of heart samples obtained from a murine model of CAV and from cardiac‐transplanted patients with CAV demonstrated that miR‐21 was most significantly expressed and was primarily localized to macrophages. Interestingly, macrophage depletion with clodronate did not significantly prolong allograft survival in mice, while conditional deletion of miR‐21 in macrophages or the use of a specific miR‐21 antagomir resulted in indefinite cardiac allograft survival and abrogated CAV. The immunophenotype, secretome, ability to phagocytose, migration, and antigen presentation of macrophages were unaffected by miR‐21 targeting, while macrophage metabolism was reprogrammed, with a shift toward oxidative phosphorylation in naïve macrophages and with an inhibition of glycolysis in pro‐inflammatory macrophages. The aforementioned effects resulted in an increase in M2‐like macrophages, which could be reverted by the addition of L‐arginine. RNA‐seq analysis confirmed alterations in arginase‐associated pathways associated with miR‐21 antagonism. In conclusion, miR‐21 is overexpressed in murine and human CAV, and its targeting delays CAV onset by reprogramming macrophages metabolism., The authors show that, after heart transplantation, microRNA‐21 is overexpressed in chronic allograft vasculopathy (CAV), that pharmacological and genetic modulation of microRNA‐21 mitigated CAV, and that microRNA‐21 antagonism abrogated CAV by reprogramming macrophage metabolism.

Specific delivery platforms for drugs to the kidney and diagnostic agents to renal cell carcinoma (RCC) constitute urgent but unfulfilled clinical needs. To address these challenges, we engineered nanocarriers that interact selectively for the first time with proximal tubule epithelial cells (PTECs) in the kidney and with RCC through the interplay between lambda light chains (LCs) attached to PEGylated polylactic-co-glycolic acid (PLGA) nanoparticles and the membrane protein megalin. Systemic administration of these light chain-conjugated nanoparticles (LC-NPs) to mice resulted in their specific retention by megalin-expressing PTECs for seven days. Repetitive dosing of LC-NPs demonstrated no renal toxicity. LC-NPs also localized selectively to megalin-expressing RCC tumors in mice. Moreover, we confirmed that both the primary tumor and lymph node metastases of human RCC express megalin, reinforcing the potential of LC-NPs for clinical use. Thus, LC-NPs can contribute potentially to improving the management of both non-oncologic and oncologic renal disorders.

Although the immune response within draining lymph nodes (DLNs) has been studied for decades, how their stromal compartment contributes to this process remains to be fully explored. Here, we show that donor mast cells were prominent activators of collagen I deposition by fibroblastic reticular cells (FRCs) in DLNs shortly following transplantation. Serial analysis of the DLN indicated that the LN stroma did not return to its baseline microarchitecture following organ rejection and that the DLN contained significant fibrosis following repetitive organ transplants. Using several FRC conditional-knockout mice, we show that induction of senescence in the FRCs of the DLN resulted in massive production of collagen I and a proinflammatory milieu within the DLN. Stimulation of herpes virus entry mediator (HVEM) on FRCs by its ligand LIGHT contributed chiefly to the induction of senescence in FRCs and overproduction of collagen I. Systemic administration of ex vivo-expanded FRCs to mice decreased DLN fibrosis and strengthened the effect of anti-CD40L in prolonging heart allograft survival. These data demonstrate that the transformation of FRCs into proinflammatory myofibroblasts is critically important for the maintenance of a proinflammatory milieu within a fibrotic DLN.

Author(s): Yonar, Merve; Uehara, Mayuko; Banouni, Naima; Kasinath, Vivek; Li, Xiaofei; Jiang, Liwei; Zhao, Jing; Bei, Fengfeng; Shin, Su Ryon; Cetrulo, Curtis L; Annabi, Nasim; Abdi, Reza | Abstract: BackgroundOrgan transplantation is a standard therapeutic strategy for irreversible organ damage, but the utility of nerve transplantation remains generally unexplored, despite its potential benefit to a large patient population. Here, we aimed to establish a feasible preclinical mouse model for understanding the cellular mechanisms behind the rejection of peripheral and optic nerves.MethodsWe performed syngenic and allogenic transplantation of optic and sciatic nerves in mice by inserting the nerve grafts inside the kidney capsule, and we assessed the allografts for signs of rejection through 14 d following transplantation. Then, we assessed the efficacy of CTLA4 Ig, Rapamycin, and anti-CD3 antibody in suppressing immune cell infiltration of the nerve allografts.ResultsBy 3 d posttransplantation, both sciatic and optic nerves transplanted from BALB/c mice into C57BL/6J recipients contained immune cell infiltrates, which included more CD11b+ macrophages than CD3+ T cells or B220+ B cells. Ex vivo immunogenicity assays demonstrated that sciatic nerves demonstrated higher alloreactivity in comparison with optic nerves. Interestingly, optic nerves contained higher populations of anti-inflammatory PD-L1+ cells than sciatic nerves. Treatment with anti-CD3 antibody reduced immune cell infiltrates in the optic nerve allograft, but exerted no significant effect in the sciatic nerve allograft.ConclusionsThese findings establish the feasibility of a preclinical allogenic nerve transplantation model and provide the basis for future testing of directed, high-intensity immunosuppression in these mice.

Ischemia reperfusion injuries (IRI) are unavoidable in solid organ transplantation. IRI augments alloimmunity but the mechanisms involved are poorly understood. Herein, we examined the effect of IRI on antigen specific alloimmunity. We demonstrate that ischemia promotes alloimmune activation, leading to more severe histological features of rejection, and increased CD4+ and CD8+ T cell graft infiltration, with a predominantly CD8+ IFNγ+ infiltrate. This process is dependent on the presence of alloreactive CD4+ T cells, where depletion prevented infiltration of ischemic grafts by CD8+ IFNγ+ T cells. IL-6 is a known driver of ischemia-induced rejection. Herein, depletion of donor antigen-presenting cells reduced ischemia-induced CD8+ IFNγ+ allograft infiltration, and improved allograft outcomes. Following prolonged ischemia, accelerated rejection was observed despite treatment with CTLA4Ig, indicating that T cell costimulatory blockade failed to overcome the immune activating effect of IRI. However, despite severe ischemic injury, treatment with anti-IL-6 and CTLA4Ig blocked IRI-induced alloimmune injury and markedly improved allograft survival. We describe a novel pathway where IRI activates innate immunity, leading to upregulation of antigen specific alloimmunity, resulting in chronic allograft injury. Based on these findings, we describe a clinically relevant treatment strategy to overcome the deleterious effect of IRI, and provide superior long-term allograft outcomes.

Phosphatidylinositol-3-kinases (PI3K) γ and δ are preferentially enriched in leukocytes, and defects in these signaling pathways have been shown to impair T cell activation. The effects of PI3Kγ and PI3Kδ on alloimmunity remain underexplored. Here, we show that both PI3Kγ −/− and PI3Kδ D910A/D910A mice receiving heart allografts have suppression of alloreactive T effector cells and delayed acute rejection. However, PI3Kδ mutation also dampens regulatory T cells (Treg). After treatment with low dose CTLA4-Ig, PI3Kγ −/−, but not PI3Κδ D910A/D910A, recipients exhibit indefinite prolongation of heart allograft survival. PI3Kδ D910A/D910A Tregs have increased apoptosis and impaired survival. Selective inhibition of PI3Kγ and PI3Kδ (using PI3Kδ and dual PI3Kγδ chemical inhibitors) shows that PI3Kγ inhibition compensates for the negative effect of PI3Kδ inhibition on long-term allograft survival. These data serve as a basis for future PI3K-based immune therapies for transplantation., Phosphatidylinositol-3-kinases (PI3K) γ and δ are key regulators of T cell signaling. Here the author show, using mouse heart allograft transplantation models, that PI3Kγ or PI3Kδ deficiency prolongs graft survival, but selective inhibition of PI3Kγ or PI3Kδ reveals alternative transplant survival outcomes post CTLA4-Ig treatment.

Studies of NISHIDA Kitarō (西田幾多郎) (1870–1945) in the field of philosophy often treat the Buddhist dimension of his work. There are plenty of literary works as well as abundant scholarly papers on this theme in Japanese that make this Buddhist aspect of Nishida distinctly evident. Outside of Japan, American academic circles, with their 60 years’ history of studies on Nishida’s philosophy, tend to regard his philosophy as Buddhist philosophy. Some scholars’ interpretations seem to place much emphasis on the identity of Nishida’s philosophy as Mahāyāna Buddhism, especially Zen 禅, as if to claim that his philosophy is simply what expresses Buddhist thought in philosophical language. But Nishida himself took precautions against this sort of viewpoint that regarded his philosophy solely as Zen. In this paper, I will restrict myself to the task of taking up Zen in relation to Nishida. However, the principal course of our reflection will focus on the “theory of the body” that Nishida earnestly formulated after the 1930s for the purpose of relating his experiences of self-cultivation, in particular sitting meditation, to his philosophical thinking. Nishida’s theory of the body explains the human body through his original concepts and expressions such as “active intuition” (J. kōiteki chokkan 行為的直観), “historical body” (J. rekishiteki shintai 歴史的身体), and “from the made to the making” (J. tsukurartea mono kara tsukuru mono e 作られたものから作るものへ). Here, the body is conceived of as a medium for the historical world as well as for the human being existing therein. The concepts of his later philosophy are characterized, on one hand, by this somatic vision, and, on the other hand, by the “absolutely contradictory self-identity” (J. zettaimujunteki jikodōitsu 絶対矛盾的自己同一), “inverse correlation” (J. gyakutaiō 逆対応) and “depth in the ordinary” (J. heijōtei 平常底), of which the latter two are crucial concepts of his final stage, that is, his philosophy of religion. My purpose will be to clarify any link between his theory of the body and other key concepts relative to his philosophy of religion. This question generally seems to have been put aside: how did Nishida as a Buddhist philosopher assimilate self-cultivation from his own life into his theory of the body and, furthermore, his philosophy of religion.

Cancer therapies kill tumors either directly or indirectly by evoking immune responses and have been combined with varying levels of success. Here, we describe a paradigm to control cancer growth that is based on both direct tumor killing and the triggering of protective immunity. Genetic ablation of serine protease inhibitor SerpinB9 (Sb9) results in the death of tumor cells in a granzyme B (GrB)-dependent manner. Sb9-deficient mice exhibited protective T cell-based host immunity to tumors in association with a decline in GrB-expressing immunosuppressive cells within the tumor microenvironment (TME). Maximal protection against tumor development was observed when the tumor and host were deficient in Sb9. The therapeutic utility of Sb9 inhibition was demonstrated by the control of tumor growth, resulting in increased survival times in mice. Our studies describe a molecular target that permits a combination of tumor ablation, interference within the TME, and immunotherapy in one potential modality.

SUMMARY Active-targeted delivery to lymph nodes represents a major advance toward more effective treatment of immune-mediated disease. The MECA79 antibody recognizes peripheral node address in molecules expressed by high endothelial venules of lymph nodes. By mimicking lymphocyte trafficking to the lymph nodes, we have engineered MECA79-coated microparticles containing an immunosuppressive medication, tacrolimus. Following intravenous administration, MECA79-bearing particles showed marked accumulation in the draining lymph nodes of transplanted animals. Using an allograft heart transplant model, we show that targeted lymph node delivery of microparticles containing tacrolimus can prolong heart allograft survival with negligible changes in tacrolimus serum level. Using MECA79 conjugation, we have demonstrated targeted delivery of tacrolimus to the lymph nodes following systemic administration, with the capacity for immune modulation in vivo., Graphical Abstract

A primary goal in the management of burn wounds is early wound closure. The use of skin allografts represents a lifesaving strategy for severe burn patients, but their ultimate rejection limits their potential efficacy and utility. IL-6 is a major pleiotropic cytokine which critically links innate and adaptive immune responses. Here, we devised anti-IL-6 receptor eluting gelatin methacryloyl (GelMA) biomaterials (GelMA/anti-IL-6), which were implanted at the interface between the wound beds and skin allografts. Our visible light crosslinked GelMA/anti-IL-6 immunomodulatory biomaterial (IMB) demonstrated a stable kinetic release profile of anti-IL-6. In addition, the incorporation of anti-IL-6 within the GelMA hydrogel had no effect on the mechanical properties of the hydrogels. Using a highly stringent skin transplant model, the GelMA/anti-IL-6 IMB almost doubled the survival of skin allografts. The use of GelMA/anti-IL-6 IMB was far superior to systemic anti-IL-6 receptor treatment in prolonging skin allograft survival. As compared to the untreated control group, skin from the GelMA/anti-IL-6 IMB group contained significantly fewer alloreactive T cells and macrophages. Interestingly, the environmental milieu of the draining lymph nodes (DLNs) of the mice implanted with the GelMA/anti-IL-6 IMB was also considerably less pro-inflammatory. The percentage of CD4+ IFNγ+ cells was much lower in the DLNs of the GelMA/anti-IL-6 IMB group in comparison to the GelMA group. These data highlight the importance of localized immune delivery in prolonging skin allograft survival and its potential utility in treating patients with severe burns.

Recent studies in cancer research have focused intensely on the antineoplastic effects of immune checkpoint inhibitors. While the development of these inhibitors has progressed successfully, strategies to further improve their efficacy and reduce their toxicity are still needed. We hypothesized that the delivery of anti–PD-1 antibody encapsulated in PLGA nanoparticles (anti–PD-1 NPs) to the spleen would improve the antitumor effect of this agent. Unexpectedly, we found that mice treated with a high dose of anti–PD-1 NPs exhibited significantly higher mortality compared with those treated with free anti–PD-1 antibody, due to the overactivation of T cells. Administration of anti–PD-1 NPs to splenectomized LT-α–/– mice, which lack both lymph nodes and spleen, resulted in a complete reversal of this increased mortality and revealed the importance of secondary lymphoid tissues in mediating anti–PD-1–associated toxicity. Attenuation of the anti–PD-1 NPs dosage prevented toxicity and significantly improved its antitumor effect in the B16-F10 murine melanoma model. Furthermore, we found that anti–PD-1 NPs undergo internalization by DCs in the spleen, leading to their maturation and the subsequent activation of T cells. Our findings provide important clues that can lead to the development of strategies to enhance the efficacy of immune checkpoint inhibitors.

The targeted delivery of therapeutic drugs to lymph nodes (LNs) provides an unprecedented opportunity to improve the outcomes of transplantation and immune-mediated diseases. The high endothelial venule is a specialized segment of LN vasculature that uniquely expresses peripheral node addressin (PNAd) molecules. PNAd is recognized by MECA79 mAb. We previously generated a MECA79 mAb–coated microparticle (MP) that carries tacrolimus. Although this MP trafficked to LNs, it demonstrated limited therapeutic efficacy in our transplant model. Here, we have synthesized a nanoparticle (NP) as a carrier of anti-CD3, and optimized the conjugation strategy to coat the NP surface with MECA79 mAb (MECA79-anti-CD3-NP) to enhance LN accumulation. As compared with nonconjugated NPs, a significantly higher quantity of MECA79-NPs accumulated in the draining lymph node (DLN). Many MECA79-NPs underwent internalization by T cells and dendritic cells within the LNs. Short-term treatment of murine cardiac allograft recipients with MECA79-anti-CD3-NP resulted in significantly prolonged allograft survival in comparison with the control groups. Prolonged graft survival following treatment with MECA79-anti-CD3-NP was characterized by a significant increase in intragraft and DLN Treg populations. Treg depletion abrogated the prolongation of heart allograft survival. We believe this targeted approach of drug delivery could redefine the methods of administering immune therapeutics in transplantation.

The contribution of the kidney-draining lymph node (KLN) to the pathogenesis of ischemia-reperfusion injury (IRI) of the kidney and its subsequent recovery has not been explored in depth. In addition, the mechanism by which repetitive IRI contributes to renal fibrosis remains poorly understood. Herein, we have found that IRI of the kidney is associated with expansion of high endothelial venules (HEVs) and activation of fibroblastic reticular cells (FRCs) in the KLN, as demonstrated by significant expansion in the extracellular matrix. The lymphotoxin α signaling pathway mediates activation of FRCs, and chronic treatment with lymphotoxin β receptor-immunoglobulin fusion protein (LTβr-Ig) resulted in marked alteration of the KLN as well as augmentation of renal fibrosis. Depletion of FRCs reduced T cell activation in the KLN and ameliorated renal injury in acute IRI. Repetitive renal IRI was associated with senescence of FRCs, fibrosis of the KLN, and renal scarring, which were ameliorated by FRC administration. Therefore, our study emphasizes the critical role of FRCs in both the initiation and repair phases of injury following IRI of the kidney.

In transplantation, donor dendritic cells (do-DCs) initiate the alloimmune response either by direct interaction with host T cells or by transferring intact donor MHC to host DCs. However, how do-DCs can be targeted for improving allograft survival is still unclear. Here we show CD103+ DCs are the major do-DC subset involved in the acute rejection of murine skin transplants. In the absence of CD103+ do-DCs, less donor MHC-II is carried to host lymph nodes, fewer allogenic T cells are primed and allograft survival is prolonged. Incubation of skin grafts with the anti-inflammatory mycobacterial protein DnaK reduces donor MHC-II on CD103+DCs and prolongs graft survival. This effect is mediated through IL-10-induced March1, which ubiquitinates and decreases MHC-II levels. Importantly, in vitro pre-treatment of human DCs with DnaK reduces their ability to prime alloreactive T cells. Our findings demonstrate a novel therapeutic approach to dampen alloimmunity by targeting donor MHC-II on CD103+DCs., Donor-derived dendritic cells (do-DC) in the graft can contribute to the induction of alloimmunity and tissue rejection, but how do-DC can be targeted for improving graft survival is unclear. Here the authors show that reducing MHC-II expression on do-DCs by DnaK pre-treatment can decrease the priming of alloimmunity and prolong graft survival in mouse models.

The clonal expansion of effector T cells and subsequent generation of memory T cells are critical in determining the outcome of transplantation. While cytotoxic T lymphocytes induce direct cytolysis of target cells through secretion of Granzyme-B (GrB), they also express cytoplasmic serine protease inhibitor-6 (Spi6) to protect themselves from GrB that has leaked from granules. Here, we studied the role of GrB/Spi6 axis in determining clonal expansion of alloreactive CD8-T cells and subsequent generation of memory CD8-T cells in transplantation. CD8-T cells from Spi6(-/-) mice underwent more GrB mediated apoptosis upon alloantigen stimulation in vitro and in vivo following adoptive transfer into an allogeneic host. Interestingly, while OT1.Spi6(-/-) CD8 T cells showed significantly lower clonal expansion following skin transplants from OVA mice, there was no difference in the size of the effector memory CD8-T cells long after transplantation. Furthermore, lack of Spi6 resulted in a decrease of short-lived-effector-CD8-cells but did not impact the pool of memory-precursor-effector-CD8-cells. Similar results were found in heart transplant models. Our findings suggest that the final alloreactive CD8-memory-pool-size is independent from the initial clonal-proliferation as memory precursors express low levels of GrB and therefore are independent of Spi6 for survival. These data advance our understanding of memory T cells generation in transplantation and provide basis for Spi6 based strategies to target effector T cells.

Ischemia reperfusion injuries (IRI) are unavoidable in solid organ transplantation. IRI augments alloimmunity but the mechanisms involved are poorly understood. Herein, we examined the effect of IRI on antigen specific alloimmunity. We demonstrate that ischemia promotes alloimmune activation, leading to more severe histological features of rejection, and increased CD4+ and CD8+ T cell graft infiltration, with a predominantly CD8+ IFNγ+ infiltrate. This process is dependent on the presence of alloreactive CD4+ T cells, where depletion prevented infiltration of ischemic grafts by CD8+ IFNγ+ T cells. IL-6 is a known driver of ischemia-induced rejection. Herein, depletion of donor antigen-presenting cells reduced ischemia-induced CD8+ IFNγ+ allograft infiltration, and improved allograft outcomes. Following prolonged ischemia, accelerated rejection was observed despite treatment with CTLA4Ig, indicating that T cell costimulatory blockade failed to overcome the immune activating effect of IRI. However, despite severe ischemic injury, treatment with anti-IL-6 and CTLA4Ig blocked IRI-induced alloimmune injury and markedly improved allograft survival. We describe a novel pathway where IRI activates innate immunity, leading to upregulation of antigen specific alloimmunity, resulting in chronic allograft injury. Based on these findings, we describe a clinically relevant treatment strategy to overcome the deleterious effect of IRI, and provide superior long-term allograft outcomes.

Ischemia-reperfusion injury (IRI) evokes intragraft inflammatory responses, which markedly augment alloimmune responses against the graft. Understanding the mechanisms underlying these responses is fundamental to develop therapeutic regimens to prevent/ameliorate organ IRI. Here, we demonstrate that IRI results in a marked increase in mitochondrial damage and autophagy in dendritic cells (DCs). While autophagy is a survival mechanism for ischemic DCs, it also augments their production of interleukin (IL)-6. Allograft-derived dendritic cells (ADDCs) lacking autophagy-related gene 5 (Atg5) showed higher death rates posttransplantation. Transplanted ischemic hearts from CD11cCre/Atg5 conditional knockout mice showed marked reduction in intragraft expression of IL-6 compared with controls. To antagonize the effect of IL-6 locally in the heart, we synthesized novel anti-IL-6 nanoparticles with capacity for controlled release of anti-IL-6 over time. Compared with systemic delivery of anti-IL-6, localized delivery of anti-IL-6 significantly reduced chronic rejection with a markedly lower amount administered. Despite improved allograft histology, there were no changes to splenic T cell populations, illustrating the importance of local IL-6 in driving chronic rejection after IRI. These data carry potential clinical significance by identifying an innovative, targeted strategy to manipulate organs before transplantation to diminish inflammation, leading to improved long-term outcomes.

One of the key unmet needs to improve long-term outcomes of heart transplantation is to develop accurate, noninvasive, and practical diagnostic tools to detect transplant rejection. Early intragraft inflammation and endothelial cell injuries occur prior to advanced transplant rejection. We developed a novel diagnostic imaging platform to detect early declines in microvascular perfusion (MP) of cardiac transplants using contrast-enhanced ultrasonography (CEUS). The efficacy of CEUS in detecting transplant rejection was tested in a murine model of heart transplants, a standard preclinical model of solid organ transplant. As compared to the syngeneic groups, a progressive decline in MP was demonstrated in the allografts undergoing acute transplant rejection (40%, 64%, and 92% on days 4, 6, and 8 posttransplantation, respectively) and chronic rejection (33%, 33%, and 92% on days 5, 14, and 30 posttransplantation, respectively). Our perfusion studies showed restoration of MP following antirejection therapy, highlighting its potential to help monitor efficacy of antirejection therapy. Our data suggest that early endothelial cell injury and platelet aggregation contributed to the early MP decline observed in the allografts. High-resolution MP mapping may allow for noninvasive detection of heart transplant rejection. The data presented have the potential to help in the development of next-generation imaging approaches to diagnose transplant rejection.

OBJECTIVES: The objective of this study was to analyse the relationship between the intraoperative transit-time flow measurement (TTFM) parameter values and the postoperative angiographic results of gastroepiploic arterial (GEA) grafts to the right coronary artery (RCA). We investigated whether the intraoperative TTFM parameter values are reliable indicators of early patency in GEA grafts to the RCA. METHODS: Patients undergoing off-pump coronary artery bypass surgery with GEA grafts were included in this study. Eighty-three GEA grafts were individually anastomosed and examined by angiography 1 week after surgery. The quality of each graft was graded using FitzGibbon grading (Study 1) and graft-flow grading (Study 2). RESULTS: Study 1: Seventy-two grafts were determined as Grade A and 11 as Grades B or O. There were no significant differences in the average of mean graft flow (MGF), pulsatility index or diastolic filling percentage between Grade A and Grades B or O grafts. Study 2: Sixty-two grafts were graded as good-graft dominant, 16 as bidirectional and 5 as occlusion including string. The average of the MGF, pulsatility index and diastolic filling percentage in the grafts graded as bidirectional and occlusion including string were not significantly different from those of grafts graded as good-graft dominant. CONCLUSIONS: Previously reported cut-off values for intraoperative TTFM parameters could not be adapted for the early patency of GEA grafts to the RCA. However, the smoothness of the graft-flow curve may be a reliable predictor of postoperative graft patency.

Constitutive proteasomes (c-20S) are ubiquitously expressed cellular proteases that degrade polyubiquitinated proteins and regulate cell functions. An isoform of proteasome, the immunoproteasome (i-20S), is highly expressed in human T cells, dendritic cells (DCs), and B cells, suggesting that it could be a potential target for inflammatory diseases, including those involving autoimmunity and alloimmunity. Here, we describe DPLG3, a rationally designed, noncovalent inhibitor of the immunoproteasome chymotryptic subunit β5i that has thousands-fold selectivity over constitutive β5c. DPLG3 suppressed cytokine release from blood mononuclear cells and the activation of DCs and T cells, diminished accumulation of effector T cells, promoted expression of exhaustion and coinhibitory markers on T cells, and synergized with CTLA4-Ig to promote long-term acceptance of cardiac allografts across a major histocompatibility barrier. These findings demonstrate the potential value of using brief posttransplant immunoproteasome inhibition to entrain a long-term response favorable to allograft survival as part of an immunomodulatory regimen that is neither broadly immunosuppressive nor toxic.

To evaluate the association of previous abdominal aortic aneurysm (AAA) graft replacement with infradiaphragmatic malperfusion in patients with acute aortic dissection.Between November 2006 and June 2011, 133 patients were referred to our hospital for management of acute aortic dissection. Eight (6.0 %) of these patients had undergone AAA graft replacement prior to the acute aortic dissection. We compared the computed tomography (CT) images of these 8 patients with those of the remaining 125 patients without previous AAA graft replacement, in terms of organ ischemia as a complication induced by acute aortic dissection.Infradiaphragmatic malperfusion from acute aortic dissection was confirmed in four of the eight patients who had undergone AAA graft replacement. Contrasted CT scan images indicated that the main cause of infradiaphragmatic malperfusion was collapse of the true lumen from compression by the false lumen into the suprarenal aorta. Although there was no significant difference between the groups in terms of cerebral ischemia and myocardial ischemia, bilateral leg ischemia and visceral ischemia occurred more frequently in the patients who had undergone AAA graft replacement.Previous AAA graft replacement is a risk factor for infradiaphragmatic malperfusion in patients with acute aortic dissection.