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Background Allosensitization can be a significant barrier to transplantation for some patients, and previous studies suggested that pre-transplant allosensitization was associated with worse outcomes after lung transplantation. However, human leukocyte antigen (HLA) antibody testing has evolved significantly over the past 10 years, and current assays are highly sensitive and specific. Methods We examined the impact of pre-transplant allosensitization on post-transplant outcomes in the era of solid-phase multiplex HLA antibody detection assays in this retrospective, single-center study of 304 adult transplant recipients between January 1, 2006, and December 31, 2012. We accepted donor organs for allosensitized patients if a virtual crossmatch was compatible with all previously identified antibodies. Results In univariate and multivariate Cox proportional hazards models, pre-transplant allosensitization, the calculated panel reactive antibody, and the number of pre-transplant HLA antibodies were not associated with the development of acute cellular rejection, lymphocytic bronchiolitis, donor-specific HLA antibodies, chronic lung allograft dysfunction, or graft failure. Conclusions Pre-transplant allosensitization does not adversely affect outcomes after lung transplantation when the potentially reactive HLAs are avoided in the donor by a virtual crossmatch with the recipient. [ABSTRACT FROM AUTHOR]

Background Bronchiolitis obliterans syndrome (BOS), chronic lung allograft rejection, remains an impediment for the function of the transplanted organ. In this study, we defined the role of the microRNA (miRNA) miR-144 in fibroproliferation leading to BOS. Methods Biopsy specimens were obtained from 20 lung transplant recipients with BOS( + ) and 19 without BOS( – ). Expression of miR-144 and its target, transforming growth factor-β (TGF-β)–induced factor homeobox 1(TGIF1), were analyzed by real-time polymerase chain reaction and Western blot. Overexpression of miR-144 and luciferase reporter genes were performed to elucidate miRNA-target interactions. The function of miR-144 was evaluated by transfecting fibroblasts and determining the response to TGF-β by analyzing Sma- and Mad-related family (Smads), fibroblast growth factor, TGF-β, and vascular endothelial growth factor. Smooth muscle actin-α–positive stress fibers and F-actin filaments in lung fibroblasts were analyzed by immunofluorescence. Results Analysis of miR-144 in the biopsy specimens demonstrated 4.1 ± 0.8-fold increases in BOS + compared with BOS – patients, with a significant reduction in TGIF1 (3.6 ± 1.2-fold), a corepressor of Smads. In vitro transfection confirmed that over-expression of miR-144 results in a reduction in TGIF1 and an increase in SMAD2, SMAD4, fibroblast growth factor-6, TGF-β, and vascular endothelial growth factor. Increasing miR-144 by transfecting, increased smooth muscle actin-α and fibronectin, and knockdown of miR-144 diminished fibrogenesis in MRC-5 fibroblasts. Conclusions miR-144 is a critical regulator of the TGF-β signaling cascade and is over-expressed in lungs with BOS. Therefore, miR-144 is a potential target toward preventing fibrosis leading to BOS after lung transplant. [ABSTRACT FROM AUTHOR]

Neutrophils are critical mediators of innate immune responses and contribute to tissue injury. However, immune pathways that regulate neutrophil recruitment to injured tissues during noninfectious inflammation remain poorly understood. DAP12 is a cell membrane-associated protein that is expressed in myeloid cells and can either augment or dampen innate inflammatory responses during infections. To elucidate the role of DAP12 in pulmonary ischemia/reperfusion injury (IRI), we took advantage of a clinically relevant mouse model of transplant-mediated lung IRI. This technique allowed us to dissect the importance of DAP12 in tissue-resident cells and those that infiltrate injured tissue from the periphery during noninfectious inflammation. Macrophages in both mouse and human lungs that have been subjected to cold ischemic storage express DAP12. We found that donor, but not recipient, deficiency in DAP12 protected against pulmonary IRI. Analysis of the immune response showed that DAP12 promotes the survival of tissue-resident alveolar macrophages and contributes to local production of neutrophil chemoattractants. Intravital imaging demonstrated a transendothelial migration defect into DAP12-deficient lungs, which can be rescued by local administration of the neutrophil chemokine CXCL2. We have uncovered a previously unrecognized role for DAP12 expression in tissue-resident alveolar macrophages in mediating acute noninfectious tissue injury through regulation of neutrophil trafficking. [ABSTRACT FROM AUTHOR]

Background There is accumulating evidence that extracellular adenosine triphosphate (eATP) promotes many of the underlying mechanisms that exacerbate acute lung injury. However, much of these data are from inbred rodent models, indicating the need for further investigation in higher vertebrates to better establish clinical relevance. To this end we evaluated a human recombinant apyrase therapy in a canine warm pulmonary ischemia-reperfusion injury (IRI) model and measured eATP levels in human lung recipients with or without primary lung graft dysfunction (PGD). Methods Warm ischemia was induced for 90 minutes in the left lung of 14 mongrel dogs. Seven minutes after reperfusion, the apyrase APT102 (1 mg/kg, n = 7) or saline vehicle ( n = 7) was injected into the pulmonary artery. Arterial blood gases were obtained every 30 minutes up to 180 minutes after reperfusion. Bronchioalveolar lavage fluid (BALF) was analyzed for eATP concentration, cellularity, and inflammatory mediator accumulation. Thirty bilateral human lung transplant recipients were graded for immediate early PGD and assessed for BALF eATP levels. Results APT102-treated dogs had progressively better lung function and less pulmonary edema during the 3-hour reperfusion period compared with vehicle-treated controls. Protection from IRI was observed, with lower BALF eATP levels, fewer airway leukocytes, and blunted inflammatory mediator expression. Human lung recipients with moderate to severe PGD had significantly higher eATP levels compared with recipients without this injury. Conclusions Extracellular ATP accumulates in acutely injured canine and human lungs. Strategies that target eATP reduction may help protect lung recipients from IRI. [ABSTRACT FROM AUTHOR]

Memory T lymphocytes are commonly viewed as a major barrier for long-term survival of organ allografts and are thought to accelerate rejection responses due to their rapid infiltration into allografts, low threshold for activation, and ability to produce inflammatory mediators. Because memory T cells are usually associated with rejection, preclinical protocols have been developed to target this population in transplant recipients. Here, using a murine model, we found that costimulatory blockade-mediated lung allograft acceptance depended on the rapid infiltration of the graft by central memory CD8+ T cells (CD44(hi)CD62L(hi)CCR7+). Chemokine receptor signaling and alloantigen recognition were required for trafficking of these memory T cells to lung allografts. Intravital 2-photon imaging revealed that CCR7 expression on CD8+ T cells was critical for formation of stable synapses with antigen-presenting cells, resulting in IFN-γ production, which induced NO and downregulated alloimmune responses. Thus, we describe a critical role for CD8+ central memory T cells in lung allograft acceptance and highlight the need for tailored approaches for tolerance induction in the lung. [ABSTRACT FROM AUTHOR]

Memory T lymphocytes are commonly viewed as a major barrier for long-term survival of organ allografts and are thought to accelerate rejection responses due to their rapid infiltration into allografts, low threshold for activation, and ability to produce inflammatory mediators. Because memory T cells are usually associated with rejection, preclinical protocols have been developed to target this population in transplant recipients. Here, using a murine model, we found that costimulatory blockade--p> CCR7+). Chemokine receptor signaling and alloantigen recognition were required for trafficking of these memory T cells to lung allografts. Intravital 2-photon imaging revealed that CCR7 expression on CD8+ T cells was critical for formation of stable synapses with antigen-presenting cells, resulting in IFN-γ production, which induced NO and downregulated alloimmune responses. Thus, we describe a critical role for CD8+ central memory T cells in lung allograft acceptance and highlight the need for tailored approaches for tolerance induction in the lung. [ABSTRACT FROM AUTHOR]

Reverse cholesterol transport (RCT) refers to the mobilization of cholesterol on HDL particles (HDL-C) from extravascular tissues to plasma, ultimately for fecal excretion. Little is known about how HDL-C leaves peripheral tissues to reach plasma. We first used 2 models of disrupted lymphatic drainage from skin -- 1 surgical and the other genetic -- to quantitatively track RCT following injection of [³H]-cholesterol-loaded macrophages upstream of blocked or absent lymphatic vessels. Macrophage RCT was markedly impaired in both models, even at sites with a leaky vasculature. Inhibited RCT was downstream of cholesterol efflux from macrophages, since macrophage efflux of a fluorescent cholesterol analog (BODIPY-cholesterol) was not altered by impaired lymphatic drainage. We next addressed whether RCT was mediated by lymphatic vessels from the aortic wall by loading the aortae of donor atherosclerotic Apoe-deficient mice with [²H]6-labeled cholesterol and surgically transplanting these aortae into recipient Apoe-deficient mice that were treated with anti-VEGFR3 antibody to block lymphatic regrowth or with control antibody to allow such regrowth. [²H]-Cholesterol was retained in aortae of anti-VEGFR3-treated mice. Thus, the lymphatic vessel route is critical for RCT from multiple tissues, including the aortic wall. These results suggest that supporting lymphatic transport function may facilitate cholesterol clearance in therapies aimed at reversing atherosclerosis. [ABSTRACT FROM AUTHOR]

The authors discuss the failure of adaptive immune system in mediating the immunosurveillance of lung cancer growth. The authors state that the success for immunotherapeutic approach against lung cancer is limited as compared to prostate cancer and melanoma. The authors also highlight the dominant role of the innate immune system in the immunosurveillance of lung cancer.

The mechanisms that link bacterial infection to solid organ rejection remain unclear. In this study, we show that following the establishment of lung allograft ac-ceptance in mice, Pseudomonas aeruginosa airway in-fection induces a G-CSF--dependent neutrophilia that stimulates acute rejection. Graft-infiltrating neutro-phils sharply upregulate the B7 molecules CD80 and CD86, but they do not express CD40 or MHC class II in response to P. aeruginosa infection. Neutrophil B7 promotes naive CD4+ T cell activation and intragraft IL-2+, IFN-'V+) and IL-17+ T lymphocyte accumula-tion. Intravital two-photon microscopy reveals direct interactions between neutrophils and CD4+ T cells within pulmonary allografts. Importantly, lung rejec-tion in P. aeruginosa-infectcd recipients is triggered by CD80/86 on neutrophils and can be prevented by B7 blockade without affecting clearance of this pathogen. These data show that neutrophils enhance T cell acti-vation through B7 trans-costimulation and suggest that inhibiting neutrophil-mediated alloimmunity can be accomplished without compromising bacterial immune surveillance. [ABSTRACT FROM AUTHOR]

Abstract: The infiltration of neutrophils and monocytes is a prominent feature of inflammatory diseases including human rheumatoid arthritis. Understanding how neutrophil recruitment is regulated during pathogenesis is crucial for developing anti-inflammatory therapies. We optimized the K/B×N serum-induced mouse arthritis model to study neutrophil trafficking dynamics in vivo using two-photon microscopy. Arthritogenic serum was injected subcutaneously into one hind footpad to induce a local arthritis with robust neutrophil recruitment. Using this approach, we showed that the depletion of monocytes with clodronate liposomes impaired neutrophil recruitment specifically at the transendothelial migration step. The depletion of CCR2+ monocytes with the monoclonal antibody MC-21 reproduced these effects, implicating CCR2+ monocytes as key regulators of neutrophil extravasation during arthritis initiation. However, monocyte depletion did not prevent neutrophil extravasation in response to bacterial challenge. These findings suggest that anti-inflammatory therapies targeting monocytes may act in part through antagonizing neutrophil extravasation at sites of aseptic inflammation. [Copyright &y& Elsevier]

Two-photon intravital microscopy has substantially broadened our understanding of tissue- and organ-specific differences in the regulation of inflammatory responses. However, little is known about the dynamic regulation of leukocyte recruitment into inflamed heart tissue, largely due to technical difficulties inherent in imaging moving tissue. Here, we report a method for imaging beating murine hearts using intravital 2-photon microscopy. Using this method, we visualized neutrophil trafficking at baseline and during inflammation. Ischemia reperfusion injury induced by transplantation or transient coronary artery ligation led to recruitment of neutrophils to the heart, their extravasation from coronary veins, and infiltration of the myocardium where they formed large clusters. Grafting hearts containing mutant ICAM-1, a ligand important for neutrophil recruitment, reduced the crawling velocities of neutrophils within vessels, and markedly inhibited their extravasation. Similar impairment was seen with the inhibition of Mac-1, a receptor for ICAM-1. Blockade of LFA-1, another ICAM-1 receptor, prevented neutrophil adherence to endothelium and extravasation in heart grafts. As inflammatory responses in the heart are of great relevance to public health, this imaging approach holds promise for studying cardiac-specific mechanisms of leukocyte recruitment and identifying novel therapeutic targets for treating heart disease. [ABSTRACT FROM AUTHOR]

The article highlights a study which examined whether sepsis is associated with changes in host and innate adaptive immunity in the U.S. The spleen and lung tissues of intensive care unit (ICU) patients with severe sepsis were examined post-mortem. Procedures performed include cytokine secretion assays, immunohistochemical staining, and immunophenotyping of cell surface receptor-ligand expression profiles. Results of the study revealed that ICU patients who died following sepsis have flow cytometric, biochemical and immunohistochemical results consistent with immunosuppression.

the lung is constantly exposed to both innocuous and potentially noxious antigens, a thorough understanding of both innate and adaptive immune responses in this organ is of the essence. Imaging modalities such as magnetic resonance imaging, positron emission tomography, and confocal microscopy have expanded our knowledge about various molecular processes and cellular responses in the lung. Two-photon microscopy has evolved into a powerful tool to observe cellular interactions in real time and has markedly expanded our understanding of the immune system. Recently, two-photon microscopy has also been utilized to image the murine lung. As immune responses in the lung differ from those in other non-lymphoid tissues, this technique holds great promise to advance our knowledge of the biology that underlies a wide spectrum of pulmonary diseases. [ABSTRACT FROM AUTHOR]

The diagnosis of aortic graft infection and aortoenteric fistula can be difficult to establish using conventional radiographic imaging modalities. Positron emission tomography (PET) imaging with 18-fluorodeoxyglucose (FDG) can rapidly provide anatomically clear images and define areas of inflammation with increased glucose metabolism. In this report the authors present a case of aortoenteric fistula diagnosed by FDG-PET, Early diagnosis led to rapid surgical intervention with graft removal and extraanatomic bypass. These encouraging results warrant larger controlled studies to evaluate the utility of FDG-PET in the diagnosis of prosthetic aortic graft infection. [ABSTRACT FROM AUTHOR]

Background: Primary graft dysfunction (PGD) and acute cellular rejection (ACR) are important causes of early morbidity and mortality following lung and heart transplantation. While many studies have elucidated donor‐related risk factors of PGD and ACR, these complications often occur even with "ideal" donors. Therefore, we investigated potential associations of PGD and ACR between bilateral lung and heart transplant recipients from the same multiorgan donor, respectively. Methods: Between 2011 and 2017, 100 donors contributed 100 bilateral lung transplants and 100 heart transplants performed. Logistic regression analysis for PGD and Cox proportional hazards regression analysis for ACR were used to estimate the relationship of heart and lung transplants. Results: The incidence of PGD was 33% among lung and 17% among heart transplant recipients. Similarly, the incidence of ACR grade ≥ A2 for lung recipients was 38% (30/80), and the incidence of ACR grade ≥ 2R for heart recipients was 19% (15/80). There was no association between the development of PGD and ACR in lung and heart transplant recipients from the same donor, respectively. Conclusions: These findings suggest that inherent donor factors are not critical to the development of PGD and ACR after lung and heart transplantation. [ABSTRACT FROM AUTHOR]

Individuals with robust natural killer (NK) cell function incur lower rates of malignancies. To expand our understanding of genetic factors contributing to this phenomenon, we analyzed NK cells from cancer resistant and susceptible strains of mice. We identified a correlation between NK levels of the X-chromosome-located adaptor protein SLy1 and immunologic susceptibility to cancer. Unlike the case for T or B lymphocytes, where SLy1 shuttles between the cytoplasm and nucleus to facilitate signal transduction, in NK cells SLy1 functions as a ribosomal protein and is located solely in the cytoplasm. In its absence, ribosomal instability results in p53-mediated NK cell senescence and decreased clearance of malignancies. NK defects are reversible under inflammatory conditions and viral clearance is not impacted by SLy1 deficiency. Our work defines a previously unappreciated X-linked ribosomopathy that results in a specific and subtle NK cell dysfunction leading to immunologic susceptibility to cancer. [ABSTRACT FROM AUTHOR]

Aim Administration of anti-MHC class I (H-2Kb) leads to induction of transcription factor Zinc finger and BTB domain containing 7A (Zbtb7a) leading to inflammatory cascade and chronic rejection in a murine obliterative airway disease model. Development of DSA and Abs to lung-associated self-antigens (K-alpla-1 Tubulin (K α 1T) and Collagen V (Col-V) are significant risk factors in development of bronchiolitis obliterans syndrome (BOS) following human lung transplantation (LTx). The current study focused on the role of Zbtb7a in development of BOS following human LTx. Methods We analyzed 25 LTx patients that developed BOS years after LTx as well as 10 stable LTx performed at Barnes-Jewish Washington University. Kinetics of Zbtb7a expression was studied in bronchoalveolar lavage (BAL) cells. Quantitative PCR analysis was performed to evaluate mRNA levels and data was compared with the DSA, autoantibody and immunosuppression. Results Increases in the Zbtb7a expression was observed in BAL cells collected at visits immediately prior to clinical BOS diagnosis compared with earlier visits. Zbtb7a expression was significantly ( p < 0.01) increased (150%) in pre-BOS BAL cells. On the contrary, stable patients did not demonstrate any change in Zbtb7a levels. All of the BOS+ patients had developed DSA and Abs to K α 1T and Col-V. Zbtb7a expression in 13 patients who received Ab directed therapy following DSA demonstrated significant reduction along with decrease in DSA and Abs to lung self-antigens. Therefore, Zbtb7a activation is an important inducer of the DSA and autoantibody. Conclusions Up regulation of Zbtb7a was positively associated with de novo DSA and Abs to lung-associated self-antigens. Ab directed therapy significantly reduced Zbtb7a expression. We propose that Zbtb7a may be used as a prognostic marker in evaluating Ab-induced inflammation in the lung as well as efficacy of Ab directed therapy following development of DSA. [ABSTRACT FROM AUTHOR]

Aim Chronic rejection (bronchiolitis obliterans syndrome (BOS)) is the major limitation for long-term survival after lung transplantation (LTx). Its pathogenesis, however, is poorly understood and no effective predictive biomarkers have been identified. Several studies have shown that de novo development of antibodies to donor mismatched HLA (DSA) is a significant risk factor for the development of BOS. Methods Thirty LTx recipients from Barnes Jewish Hospital/Washington University School of Medicine (10 stable DSA− and BOS−, 10 DSA+ BOS− and 10 DSA+ and BOS+) were analyzed for circulating microRNAs (miRNAs). MiRNAs expression in the recipients’ serum was detected using RNA extraction and quantitative PCR analysis. Results We identified eight miRNAs which were selectively expressed on lung allograft recipients with de novo developed DSA and diagnosed with BOS in comparison to stable LTx without DSA and BOS: miR-369-5p, miR-144, miR-134, miR-10a, miR-195 miR-142-5p, miR-133b, and miR-155 ( p < 0.01). Among them, transforming growth factor beta (TGF- β ) associated miRNAs: miR-369-5p was down regulated (2.3-fold, p < 0.001), miR-144 was up-regulated (3.1-fold, p < 0.001) in the serum of LTx with DSA compared to stable, indicating their role in fibrogenesis mediated by TGF- β signalling. In addition, miR-134 involved in B cell receptor pathway was decreased ( p < 0.001) in the serum of LTx with DSA and BOS, demonstrating its role in B cell activation and DSA development following LTx. Furthermore, miR-10a, known to be associated with Treg development, was down-regulated ( p < 0.001) in LTx with DSA and BOS, demonstrating its involvement in down regulation of Treg function leading to development of DSA. Finally, results obtained from independent validation using an independent cohort of 9 stable, 7 DSA+ BOS−, and 10 DSA+ BOS+ LTx demonstrated that these miRNAs can discriminate LTx with development of DSA and BOS from those stable LTx without DSA and BOS ( p < 0.01). Conclusion Our results, for the first time, demonstrated differential expression of circulating miRNAs in lung allograft recipients with de novo development of DSA and BOS. These dysregulated miRNAs are involved in T and B cell regulation and fibrogenesis, indicating their role in the development of DSA leading to chronic lung allograft rejection. [ABSTRACT FROM AUTHOR]

Aim: De novo autoantibodies (autoAbs) against lung restricted autoantigens, namely k-alpha 1 tubulin (KAT) and collagen type V (colV), develop following transplant but their role in allograft rejection remains unclear. Using the murine model of lung transplant we investigated whether these autoAbs can abrogate immunosuppression mediated tolerance of lung allografts and induce rejection of syngeneic grafts. Methods: Abs to KAT, ColV and isotype control (n =5/group) were administered in Bl/6 murine recipients of MHC-mismatched Balb/c single left lung allografts that were tolerized using costimulatory blockade (MR1 and CTLA4-Ig). ELISPOT was used to analyze antigen specific T cells. Graft rejection was characterized using histochemistry. Syngeneic single left lung transplants were performed in B/6 mice following which Abs to KAT, ColV and isotype control were injected. Results: Lung allografts showed no rejection following co-stimulatory blockade. Administration of either KAT or colV autoAbs, but not isotype control, led to allograft rejection (but not native lungs) by day 45. This correlated with infiltration of IFN and IL-17 secreting Tcells specific to the lung-restricted autoantigens (but not Collagen II) as well as donor MHC antigens (but not against third party MHC antigens). Either KAT or colV autoAbs alone induced immunity against the other lung restricted autoantigen as well but not against non-lung antigen Collagen II. Administration of either colV or KAT autoAbs led to the rejection of syngeneic left lung grafts (but not native lungs) that was associated with infiltration of autoantigen specific IFN and IL-17 secreting T cells. Conclusions: De novo autoAbs can abrogate immunosuppression mediated lung allograft tolerance. Autoabs can lead to graft rejection in the absence of alloimmunity as evident by rejection of syngeneic grafts. AutoAbs also lead to epitope spreading and development of additional autoimmune responses against target tissue-restricted as well as donor MHC antigens. [ABSTRACT FROM AUTHOR]

Background: Although surgeons are constantly making efforts to improve efficiency of care, it is important to also optimize the patients'' understanding and satisfaction with their surgical experience. We investigated the effect of a preoperative educational video on patient outcomes and perception of surgery. Study Design: An educational video was developed outlining preoperative, operative, and postoperative expectations for patients undergoing pulmonary resection. A prospective study was conducted with 150 patients undergoing surgery with routine preoperative discussion (control group, January 2008 to June 2009) and 150 patients who were provided a supplemental video module (video or study group, September 2009 to October 2010) in addition to routine discussion. Demographics and outcomes data were recorded. Patients completed a pain survey (McGill Questionnaire) and a standardized patient satisfaction survey at discharge and within 1 month of operation. Results: The groups were similar in sex, age, comorbidities, and forced expiratory volume, 1 second, % predicted. Length of hospital stay (5.19 ± 7.4 days vs 4.31 ± 4.3 days; p = 0.2) and hospital readmission rates (12 of 134 [9%] vs 5 of 103 [4.9%]; p = 0.3) were similar for the 2 groups. At discharge, patients in the study group reported less pain at rest (0.98 ± 0.09) vs controls (1.39 ± 0.11) (p = 0.01) with no difference in pain with lifting or coughing. Patients in the study group reported better overall satisfaction with their operation (2.14 ± 0.07 vs 1.85 ± 0.07; p = 0.02), believed they were better prepared (2.01 ± 0.07 vs 1.70 ± 0.06; p = 0.006), and reported less anxiety about the surgical experience (2.79 ± 0.10 vs 2.24 ± 0.09; p = 0.0001). Conclusions: Implementation of a pulmonary resection education module improves patient preparedness, relieves anxiety, and improves pain perception. Additional development and dissemination of a comprehensive education program can improve patients'' experience with lung surgery and impact outcomes. [Copyright &y& Elsevier]