Clara cells drive eosinophil accumulation in allergic asthma
EUROPEAN RESPIRATORY JOURNAL
Authors: Sonar, S. S.; Ehmke, M.; Marsh, L. M.; Dietze, J.; Dudda, J. C.; Conrad, M. L.; Renz, H.; Nockher, W. A.
Development of allergic asthma is a complex process involving immune, neuronal and tissue cells. In the lung, Clara cells represent a major part of the "immunomodulatory barrier" of the airway epithelium. To understand the contribution of these cells to the inflammatory outcome of asthma, disease development was assessed using an adjuvant-free ovalbumin model. Mice were sensitised with subcutaneous injections of 10 mu g endotoxin-free ovalbumin in conjunction with naphthalene-induced Clara cell depletion. Clara epithelial cell depletion in the lung strongly reduced eosinophil influx, which correlated with decreased eotaxin levels and, moreover, diminished the T-helper cell type 2 inflammatory response, including interleukin (IL)-4, IL-5 and IL-13. In contrast, airway hyperresponsiveness was increased. Further investigation revealed Clara cells as the principal source of eotaxin in the lung. These findings are the first to show that Clara airway epithelial cells substantially contribute to the infiltration of eotaxin-responsive CCR3+ immune cells and augment the allergic immune response in the lung. The present study identifies Clara cells as a potential therapeutic target in inflammatory lung diseases such as allergic asthma.
Chemokine receptor patterns and right heart failure in mechanical circulatory support
JOURNAL OF HEART AND LUNG TRANSPLANTATION
Authors: Nayak, Aditi; Neill, Colin; Kormos, Robert L.; Lagazzi, Luigi; Haider, Indrani; McTiernan, Charles; Larsen, Jennifer; Inashvili, Ana; Teuteberg, Jeffrey; Bachman, Timothy N.; Hanley-Yanez, Karen; McNamara, Dennis M.; Simon, Marc A.
BACKGROUND: Right ventricular failure (RVF) complicates 9% to 44% of left ventricular assist device (LVAD) implants post-operatively. Current prediction scores perform only modestly in validation studies, and do not include immune markers. Chemokines are inflammatory signaling molecules with a fundamental role in cardiac physiology and stress adaptation. In this study we investigated chemokine receptor regulation in LVAD recipients who develop RVF. METHODS: Expression of chemokine receptor (CCR) genes 3 to 8 were examined in the peripheral blood of 1 1 1 LVAD patients, collected 24 hours before implant. RNA was isolated using a PAXgene protocol. Gene expression was assessed using a targeted microarray (RT2 Profiler PCR Array; Qiagen). Results were expressed as polymerase chain reaction (PCR) cycles to threshold and normalized to the average of 3 control genes, glyceraldehyde phosphate dehydrogenase (GAPDH), hypoxanthine phosphoribosyltransferase I (HPRTI) and beta(2)-microglobulin (B2M). Secondary outcomes studied were I-year mortality and long-term RV failure (RVF-LT). RESULTS: CCR3, CCR4, CCR6, CCR7 and CCR8 were downregulated in LVAD recipients with RVF. Within this cohort of patients, CCR4, CCR7 and CCR8 were further downregulated in those who required RV mechanical support. In addition, under-expression of CCR3 to CCR8 was independently associated with an increased risk of mortality at 1 year, even after adjusting for RVF. CCR expression did not predict RVF-LT in our patient cohort. CONCLUSIONS: Pre-LVAD CCR downregulation is associated with RVF and increased mortality after implant. Inflammatory signatures may play a major role in prognostication in this patient population. (C) 2017 International Society for Heart and Lung Transplantation. All rights reserved.