Project description:Primary graft dysfunction (PGD) continues to be a major cause of early death after lung transplantation. Moreover, there remains a lack of accurate pre-transplant molecular markers for predicting PGD. To identify distinctive gene expression signatures associated with PGD, we profiled human donor lungs using microarray technology prior to the graft implantation. The genomic profiles of 10 donor lung samples from patients who subsequently developed clinically defined severe PGD were compared with 16 case-matched donor lung samples from those who had a favorable outcome without PGD. Matched factors used were: recipient age (± 10 years), recipient gender, recipient lung disease, and type of transplantation (single or bilateral). Keywords: Observational case-control study Matched case-control observational study: 10 primary graft dysfunction cases vs 16 Good outcome cases. One replicate per array.
Project description:Primary graft dysfunction (PGD) continues to be a major cause of early death after lung transplantation. Moreover, there remains a lack of accurate pre-transplant molecular markers for predicting PGD. To identify distinctive gene expression signatures associated with PGD, we profiled human donor lungs using microarray technology prior to the graft implantation. The genomic profiles of 10 donor lung samples from patients who subsequently developed clinically defined severe PGD were compared with 16 case-matched donor lung samples from those who had a favorable outcome without PGD. Matched factors used were: recipient age (± 10 years), recipient gender, recipient lung disease, and type of transplantation (single or bilateral). Keywords: Observational case-control study
Project description:Expression profile of human donor lungs that have developed primary graft dysfunction (PGD) after lung transplantation and those that have not. In this study, we attempt to further our understanding of PGD by observing the changes in gene expression across donor lungs that developed PGD versus those that did not. Keywords: stress response
Project description:Pre-existing lung restricted autoantibodies (LRA) are associated with a higher incidence of primary graft dysfunction (PGD) although it remains unclear whether LRA can drive its pathogenesis. In syngeneic murine left lung transplant recipients, pre-existing LRA worsened graft dysfunction, which was evident by impaired gas exchange, increased pulmonary edema, and activation of damage-associated pathways in lung epithelial cells. LRA-mediated injury was distinct from ischemia-reperfusion injury since deletion of donor non-classical monocytes as well as host neutrophils could not prevent graft dysfunction in LRA-pretreated recipients. Whole LRA IgG molecule was necessary for lung injury which was mediated by the classical and alternative complement pathways and reversed by complement inhibition. However, deletion of Fc receptors in donor macrophages or mannose-binding lectin proteins failed to rescue lung function. LRA- mediated injury was localized to the transplanted lung and dependent on IL1β-mediated permeabilization of pulmonary vascular endothelium which allowed extravasation of antibodies. Genetic deletion or pharmacological inhibition of IL1R in the donor lungs prevented LRA-induced graft injury. In humans, pre-existing LRA was an independent risk factor for severe PGD and could be treated with plasmapheresis and complement blockade. We conclude that pre-existing LRA can compound ischemia-reperfusion injury to worsen PGD for which complement inhibition may be effective.
Project description:This is an RNA-seq study of human lung transplant recipients. Bronchoalveolar lavage cells were collected on the first day after lung transplant. We performed bulk RNA-sequencing on 19 lung transplant recipients with severe primary graft dysfunction (PGD) and 19 lung transplant recipients without primary graft dysfunction. As this data is human identifiable, raw data are not included in this record.
Project description:Primary Graft Dysfunction (PGD) is the predominant cause of early graft loss following lung transplantation. We recently demonstrated that donor pulmonary intravascular non-classical monocytes (NCM) initiate neutrophil recruitment. Simultaneously, host-origin classical monocytes (CM) are mobilized from the spleen and, upon entry into the allograft, permeabilize the vascular endothelium to allow neutrophil extravasation necessary for PGD. Here, we show that CCL2-CCR2 axis is necessary for CM recruitment. Surprisingly, although intravital imaging and multichannel flow cytometry revealed that pharmacological or genetic depletion of donor NCM abrogated CM recruitment, single-cell RNAseq identified donor alveolar macrophages (AM) as predominant CCL2 secretors. Unbiased transcriptomic analysis of human and murine tissues combined with murine knockouts and chimeras indicated that while IL1β was secreted by multiple cell lineages, donor NCM were responsible for the early activation of AM and CCL2 release. IL1β production by NCM was NLRP3 inflammasome-dependent and inhibited by donor treatment using a clinically approved sulphonylurea, Glyburide. Production of CCL2 in the donor AM occurred through IL1R-dependent activation of PKC and NFκB-pathway. Accordingly, we show that IL1β-dependent paracrine interaction between donor NCM and AM leads to recruitment of host AM necessary for PGD. Since depletion of donor NCM, IL1β or IL1R antagonism, and inflammasome inhibition, abrogated recruitment of CM as well as PGD and are feasible using FDA-approved compounds, our findings have potential for immediate clinical translation.
Project description:BACKGROUND: Hypovolemia is common in lung donors before or after brain death. However, its impact on primary graft function (PGD) remains obscure. METHODS: A clinically relevant two-hit model of PGD was established by integrating hypovolemic shock (HS) and cold ischemia-reperfusion in a mouse model of orthotopic lung transplantation (LTx) from C57BL/6 to Balb/c. At -48 hours, HS was induced to donor by withdrawal of blood from femoral artery and keeping the mean arterial pressure at 15±5 mmHg for 4 h. At -24 hours, donor lungs were retrieved from mice with or without HS and stored at 0ºC until transplantation. CD11b-DTR mice were used as donor and treated with Diphtheria Toxin (DT) to deplete graft-infiltrating macrophages. RESULTS: HS mainly caused macrophage-predominant infiltration around pulmonary artery injury systemic inflammatory response, but little impairment of lung function even if in combination with cold ischemia-reperfusion. Transcriptional profiling showed HS pretreatment increased pulmonary damage and alveolar remodeling but ameliorated inflammatory infiltration when compared to one-hit model of 12 hours cold ischemia-reperfusion injury. The allografts with donor DT-treatment one day ahead of HS showed injury and dysfunction at donation and worsened further at 24 hours reperfusion, whereas the allografts with recipient DT-treatment immediately after transplantation showed similar function and histology to the control treated with saline. CONCLUSION: Donor hypovolemia causes pulmonary artery injury and infiltration but has little impact on allograft function, even in combination with 24 h cold ischemia. Graft-infiltrating macrophages are critical in protecting graft from HS-induced injury and cold ischemia-reperfusion injury.
Project description:Background: Primary graft dysfunction (PGD) remains a challenge to lung transplantation (LTx) recipients as a leading cause of poor early outcomes. New methods are needed for the rapid detection of PGD and the measurement of particle flow rate (PFR) from exhaled breath is a novel means to monitor disease. Methods: 22 recipient pigs underwent orthotopic left LTx and were evaluated for PGD on the third post-operative day. Exhaled breath particles (EBPs) and PFR were measured on mechanical ventilation. EBPs were evaluated with mass spectrometry and the proteome was compared to tissue biopsies and bronchoalveolar lavage fluid (BALF). Findings were confirmed in EBPs from 11 human transplant recipients. Results: 9 recipients developed PGD and had significantly higher PFR (686.4 (449.7-8824.0) particles per minute (ppm)) compared to recipients without PGD (116.6 (79.7-307.4) ppm, p=0.0005). From proteomic analysis, porcine and human EBP proteins recapitulated the BAL and adherens and tight junction proteins were underexpressed in PGD tissue. Conclusions: Histological and proteomic analysis found significant changes to the alveolar-capillary barrier to explain the increased PFR in recipients with PGD. Combined with the similarity of proteomic profiles between EBPs and BALF, exhaled breath measurement is proposed as a rapid and non-invasive bedside measurement of PGD.
Project description:Primary graft dysfunction (PGD) is the leading cause of early mortality after lung transplantation. Anti-collagen type-V (col(V)) immunity has been observed in animal models of ischemia-reperfusion injury (IRI) and in PGD. We hypothesized that collagen type-V is an innate danger signal contributing to PGD pathogenesis. Methods: Anti-col(V) antibody production was detected by flow cytometric assay following cultures of murine CD19+ splenic cells with col(V). Responding murine B cells were phenotyped using surface markers. RNA-Seq analysis was performed on murine CD19+ cells. Levels of anti-col(V) antibodies were measured in 188 recipients from the Lung Transplant Outcomes Group (LTOG) after transplantation. Results: Col(V) induced rapid production of anti-col(V) antibodies from murine CD19+ B cells. Subtype analysis demonstrated innate B-1 B cells bound col(V). Col(V) induced a specific transcriptional signature in CD19+ B cells with similarities to, yet distinct from, B cell receptor (BCR) stimulation. Rapid de novo production of anti-col(V) Abs was associated with an increased incidence of clinical PGD after lung transplant. Conclusions: This study demonstrated that col(V) is an rapidly recognized by B cells and has specific transcriptional signature. In lung transplants recipients the rapid seroconversion to anti-col(V) Ab is linked to increased risk of grade 3 PGD.
Project description:Lung transplantation remains the only viable therapy for patients with end-stage lung disease; however, full utilization of this treatment strategy is severely compromised by the lack of donor lung availability. For example, the vast majority of donor lungs available for transplantation are obtained from brain death (BD) individuals. Unfortunately, the autonomic storm which accompanies BD often results in neurogenic pulmonary edema (NPE), thereby either producing irreversible lung injury or leading to primary graft dysfunction following lung transplantation. We previously demonstrated that sphingosine 1-phosphate (S1P), a phospholipid angiogenic factor and major barrier-enhancing agent, as well as S1P analogues serve to reduce vascular permeability and ischemia/reperfusion (I/R) lung injury in rodents via ligation of the S1P1 receptor, S1PR1. As primary lung graft dysfunction is induced by lung vascular endothelial cell barrier dysfunction, we hypothesized that SEW-2871, a S1PR1 agonist, may attenuate NPE when administered to the donor shortly after BD. Significant lung injury was observed 4h after BD in a rat BD model with ~60% increases in BAL total protein, BAL cell counts, and lung tissue W/D weight ratios. In contrast, rats receiving SEW-2871 (0.1 mg/kg) 15 minutes after the induction of BD and assessed 4h later exhibited significant lung protection (~50% reduction, p=0.01) reflected by reduced BAL total protein, BAL cytokines concentrations, BAL albumin, BAL total cell count and lung tissue wet/dry (W/D) weights ratio. Microarray analysis at 4hrs revealed a global impact of both BD and SEW on lung gene expression with differential expression of a subclass of genes enriched in immune/inflammation response pathways across the 4 experimental groups. Overall, SEW served to attenuate the BD-mediated ie gene expression upregulation. Two potentially useful biomarkers, Tnf and Ccrl2, exhibited gene dysregulation by microarray analysis, which was validated by qPCR. We conclude that SEW-2871 significantly attenuates BD-induced lung injury and may serve as a potential candidate to improve human lung donor availability and transplantation outcomes. Animals were divided into four groups: sham, BD (A Fogarty catheter 4 Fr. was inserted and secured into the extradural space and inflated to induce BD), SEW (injection of SEW-2871), and BD/SEW. Three replicates each.