Association between the renin-angiotensin system and chronic lung allograft dysfunction.

Chronic lung allograft dysfunction (CLAD) is the major cause of death after lung transplantation. Angiotensin II (AngII), the main effector of the renin-angiotensin system, elicits fibrosis in both kidney and lung. We identified six AngII-regulated proteins (Ras homolog family member B (RHOB), bone marrow stromal cell antigen 1 (BST1), lysophospholipase 1 (LYPA1), glutamine synthetase (GLNA), thrombospondin 1 (TSP1) and laminin subunit ß2 (LAMB2)) that were increased in urine of patients with kidney allograft fibrosis. We hypothesised that the renin-angiotensin system is active in CLAD and that AngII-regulated proteins are increased in bronchoalveolar lavage fluid (BAL) of CLAD patients.We performed immunostaining of AngII receptors (AGTR1 and AGTR2), TSP1 and GLNA in 10 CLAD lungs and five controls. Using mass spectrometry, we quantified peptides corresponding to AngII-regulated proteins in BAL of 40 lung transplant recipients (stable, acute lung allograft dysfunction (ALAD) and CLAD). Machine learning algorithms were developed to predict CLAD based on BAL peptide concentrations.Immunostaining demonstrated significantly more AGTR1+ cells in CLAD versus control lungs (p=0.02). TSP1 and GLNA immunostaining positively correlated with the degree of lung fibrosis (R2=0.42 and 0.57, respectively). In BAL, we noted a trend towards higher concentrations of AngII-regulated peptides in patients with CLAD at the time of bronchoscopy, and significantly higher concentrations of BST1, GLNA and RHOB peptides in patients that developed CLAD at follow-up (p<0.05). The support vector machine classifier discriminated CLAD from stable and ALAD patients at the time of bronchoscopy (area under the curve (AUC) 0.86) and accurately predicted subsequent CLAD development (AUC 0.97).Proteins involved in the renin-angiotensin system are increased in CLAD lungs and BAL. AngII-regulated peptides measured in BAL may accurately identify patients with CLAD and predict subsequent CLAD development.

The CD8+ T cell content of transbronchial biopsies from patients with a first episode of clinically stable grade A1 cellular rejection is associated with future chronic lung allograft dysfunction.

BACKGROUND: T cells drive acute cellular rejection (ACR) and its progression to chronic lung allograft dysfunction (CLAD) following lung transplantation. International Society for Heart and Lung Transplantation grade A1 ACR without associated allograft dysfunction is often untreated, yet some patients develop progressive graft dysfunction. T-cell composition of A1 ACR lesions may have prognostic value; therefore, protein-level and epigenetic techniques were applied to transbronchial biopsy tissue to determine whether differential T-cell infiltration in recipients experiencing a first episode of stable grade A1 ACR (StA1R) is associated with early CLAD. METHODS: Sixty-two patients experiencing a first episode of StA1R were divided into those experiencing CLAD within 2 years (n = 13) and those remaining CLAD-free for 5 or more years (n = 49). Imaging mass cytometry (IMC) was used to profile the spectrum and distribution of intragraft T cell phenotypes on a subcohort (n = 16; 8 early-CLAD and 8 no early-CLAD). Immunofluorescence was used to quantify CD4+, CD8+, and FOXP3+ cells. Separately, CD3+ cells were fluorescently labeled, micro-dissected, and the degree of Treg-specific demethylated region methylation was determined. RESULTS: PhenoGraph unsupervised clustering on IMC revealed 50 unique immune cell subpopulations. Methylation and immunofluorescence analyses demonstrated no significant differences in Tregs between early-CLAD and no early-CLAD groups. Immunofluorescence revealed that patients who developed CLAD within 2 years of lung transplantation showed greater CD8+ T cell infiltration compared to those who remained CLAD-free for 5 or more years. CONCLUSIONS: In asymptomatic patients with a first episode of A1 rejection, greater CD8+ T cell content may be indicative of worse long-term outlook.

Lung Transplant Immunomodulation with Genetically Engineered Mesenchymal Stromal Cells-Therapeutic Window for Interleukin-10.

Lung transplantation results are compromised by ischemia-reperfusion injury and alloimmune responses. Ex vivo lung perfusion (EVLP) is used to assess marginal donor lungs before transplantation but is also an excellent platform to apply novel therapeutics. We investigated donor lung immunomodulation using genetically engineered mesenchymal stromal cells with augmented production of human anti-inflammatory hIL-10 (MSCsIL-10). Pig lungs were placed on EVLP for 6 h and randomized to control (n = 7), intravascular delivery of 20 × 106 (n = 5, low dose) or 40 × 106 human MSCs IL-10 (n = 6, high dose). Subsequently, single-lung transplantation was performed, and recipient pigs were monitored for 3 days. hIL-10 secretion was measured during EVLP and after transplantation, and immunological effects were assessed by cytokine profile, T and myeloid cell characterization and mixed lymphocyte reaction. MSCIL-10 therapy rapidly increased hIL-10 during EVLP and resulted in transient hIL-10 elevation after lung transplantation. MSCIL-10 delivery did not affect lung function but was associated with dose-related immunomodulatory effects, with the low dose resulting in a beneficial decrease in apoptosis and lower macrophage activation, but the high MSCIL-10 dose resulting in inflammation and cytotoxic CD8+ T cell activation. MSCIL-10 therapy during EVLP results in a rapid and transient perioperative hIL-10 increase and has a therapeutic window for its immunomodulatory effects.

Engineered mesenchymal stromal cell therapy during human lung ex vivo lung perfusion is compromised by acidic lung microenvironment.

Ex vivo lung perfusion (EVLP) is an excellent platform to apply novel therapeutics, such as gene and cell therapies, before lung transplantation. We investigated the concept of human donor lung engineering during EVLP by combining gene and cell therapies. Premodified cryopreserved mesenchymal stromal cells with augmented anti-inflammatory interleukin-10 production (MSCIL-10) were administered during EVLP to human lungs that had various degrees of underlying lung injury. Cryopreserved MSCIL-10 had excellent viability, and they immediately and efficiently elevated perfusate and lung tissue IL-10 levels during EVLP. However, MSCIL-10 function was compromised by the poor metabolic conditions present in the most damaged lungs. Similarly, exposing cultured MSCIL-10 to poor metabolic, and especially acidic, conditions decreased their IL-10 production. In conclusion, we found that "off-the-shelf" MSCIL-10 therapy of human lungs during EVLP is safe and feasible, and results in rapid IL-10 elevation, and that the acidic target-tissue microenvironment may compromise the efficacy of cell-based therapies.

miR-145 expression enhances integrin expression in SK-GT-4 cell line by down-regulating c-Myc expression.

Adenocarcinoma of the esophagus is increasing in frequency and is the 6th most common cause of cancer death in North America. In adenocarcinoma cell lines, we have previously demonstrated that expression of miR-145, leads to enhanced invasion, resistance to anoikis and better attachment to fibronectin in esophageal adenocarcinoma. In contrast, expression of miR-145 acts as a tumor suppressor in squamous cell carcinoma. The molecular mechanisms responsible for the oncogenic effects of miR-145 were investigated. In this report, we demonstrate that we can partially recreate the miR-145 effects in EAC by knock down of the expression of c-Myc, which is one of the targets of miR-145. Knocking down of c-Myc expression resulted in upregulation of integrin subunits α5 and ß3. Finally, we demonstrated that integrin α5 expression correlates to fibronectin attachment potential whereas integrin ß3 expression correlates with resistance to anoikis and invasion potential. Finally, we demonstrate that expression of miR-145 in esophageal adenocarcinoma cell line (SK-GT-4) enhances tumor growth and metastasis in a NOD/SCID xenograft model. Overall, the oncogenic potential of miR-145 in EAC appears to be mediated by downregulation of c-Myc leading to the expression of integrins subunits α5 and ß3.

MicroRNA expression profiling of esophageal cancer before and after induction chemoradiotherapy.

BACKGROUND: The prognosis for esophageal cancer is poor but may be improved by neoadjuvant therapy. A complete pathologic response (pCR) is associated with improved survival. We conducted a study to profile the expression of microRNAs (miRNAs) in esophageal cancer before and after induction therapy. Our aims were to identify those miRNAs that are differentially regulated after induction therapy and attempt to describe a miRNA pattern that could predict pCR. METHODS: Total RNA was extracted from pretreatment and posttreatment specimens from 25 patients who underwent trimodal therapy using concurrent irinotecan/cisplatin and radiotherapy followed by surgical treatment. miRNAs were labeled and hybridized to the Illumina miRNA BeadChip microarray (Illumina, Inc, San Diego, CA). Expression data was quantified using BeadStudio software (Illumina), using a cutoff for significant gene differences of p less than 0.05 with a 2-fold difference in expression. Survival analysis was performed using SPSS, version 18 (SPSS, Inc, Chicago, IL). RESULTS: Using pretreatment biopsy specimens, 71 miRNAs were significantly different between pCR and non-pCR groups. Of these, 5 miRNAs were greater than 2-fold differentially regulated, including miR-296, recently shown to be of prognostic significance in esophageal carcinoma. After induction therapy, 568 miRNAs were found to be significantly upregulated or downregulated, 111 of which had a 2-fold difference. Patients with high levels of miR-135b or miR-145 in the posttreatment biopsy specimens had significantly shorter median disease-free survival (DFS) than did those with low levels (11.5 versus 5.1 months; p=0.04; 11.5 versus 2.8 months; p=0.03). CONCLUSIONS: miRNA expression profiling of pretreatment biopsy specimens revealed 5 miRNAs differentially expressed in patients with pCR compared with patients without pCR. We have also identified 111 miRNAs significantly upregulated or downregulated after induction therapy, some of which may be predictive of outcome. Further study of these miRNAs may elucidate a novel understanding of mechanisms of resistance to chemotherapy or radiotherapy.

Local long-term expression of lentivirally delivered IL-10 in the lung attenuates obliteration of intrapulmonary allograft airways.

Obliterative bronchiolitis (OB) is a form of chronic rejection after lung transplantation. Lentiviral vectors (LVs) facilitate long-term gene transduction in many tissues and organs. We hypothesized that lentiviral gene transfer of interleukin (IL)-10, a potent immune-modulating cytokine, to the lung could modulate the alloimmune responses in the lung after transplantation. C57BL6 mice received LVs encoding luciferase, enhanced green fluorescent protein (eGFP), or human IL-10 (huIL-10) through airways and underwent repeated bioluminescent imaging, immunofluorescence imaging, or ELISA of lung tissues, respectively. Luciferase activities peaked at day 7 and were stable after day 28 to over 15 months. eGFP staining demonstrated LV-mediated gene transduction mainly in alveolar macrophages. LV-huIL-10 delivery resulted in stable long-term expression of huIL-10 in the lung tissue (average 3.66 pg/mg at 1 year). Intrapulmonary allograft tracheal transplantation (BALBc→C57BL6) was used as a model of OB. LV-huIL-10 or LV-eGFP were delivered 7 days before transplantation and compared with no LV-transfection group. Allograft airways at day 28 were almost completely obliterated in all the groups. However, at day 42, allograft airways treated with LV-huIL-10 showed a spectrum of attenuation in airway fibrosis ranging from complete obliteration through bubble-like partial opening to complete patency with epithelial coverage in association with a significantly reduced obliteration ratio compared with the other groups (p<0.05). In conclusion, lentivirus-mediated gene transduction is useful in achieving long-term transgene expression in the lung. Long-term IL-10 expression has the potential to attenuate allograft airway obliteration. LV-mediated gene therapy could be a useful strategy to prevent or treat OB after lung transplantation.