title: Proinflammatory role of epithelial cell-derived exosomes in allergic airway inflammation.
abstract: BACKGROUND
  Exosomes are nanovesicles involved in intercellular communication. Their roles in various diseases are often contextual, depending on the cell type producing them. Although few studies hint toward the proinflammatory role of bronchoalveolar lavage fluid-derived exosomes in asthmatic progression, the cell types in lungs associated with exosome-mediated crosstalk and their resultant effects remain unexplored.
  
  
  OBJECTIVE
  It is well established that exosome-mediated cellular communication can influence disease phenotypes. This study explores exosome-mediated cellular crosstalk between structural and immune cells in asthma pathogenesis.
  
  
  METHODS
  Exosomes were isolated and detected from bronchoalveolar lavage fluid of control and asthmatic mice and were quantified by using a bead-based assay. Involvement of epithelial cells and macrophages were established by using immunohistochemical techniques in lung tissue sections. The role of IL-13 in exosome production was ascertained by using various in vitro and in vivo techniques. Exosome secretion was blocked in in vitro and in vivo settings by using a chemical inhibitor, and the effects on various asthmatic features were studied.
  
  
  RESULTS
  Using combinatorial in vitro and in vivo approaches, we found that exosome secretion and production of exosome-associated proteins are higher in lungs of asthmatic mice compared with that seen in sham mice. Asthma is marked by enhanced secretion of exosomes by epithelial cells, but not macrophages, under the influence of IL-13. These epithelial cell exosomes induce proliferation and chemotaxis of undifferentiated macrophages. On the other hand, GW4869, which inhibited exosome production, resulted in a reduced population of proliferating monocytes and alleviation of various asthmatic features.
  
  
  CONCLUSIONS
  Under the influence of IL-13, epithelial cell-derived exosomes can induce enhanced proliferation and chemotaxis of undifferentiated macrophages in the lungs during asthmatic inflammatory conditions.
authors: Molecular Immunogenetics Laboratory and the Centre of Excellence for Translational Research in Asthma and Lung Disease, CSIR-Institute of Genomics and Integrative Biology, Delhi, India.
authors: Ankur
authors: A
authors: Kulshreshtha
authors: Tanveer
authors: T
authors: Ahmad
authors: Anurag
authors: A
authors: Agrawal
authors: Balaram
authors: B
authors: Ghosh
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology; D000818:Animals; D001249:Asthma / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D001597:Benzylidene Compounds / Q000494:pharmacology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D002633:Chemotaxis / Q000187:drug effects / Q000276:immunology; D004847:Epithelial Cells / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D055354:Exosomes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D007249:Inflammation / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D018793:Interleukin-13 / Q000276:immunology / Q000494:pharmacology; D008168:Lung / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009000:Monocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D020545:Respiratory Mucosa / Q000276:immunology* / Q000378:metabolism / Q000473:pathology
chemical_list: D000814:Aniline Compounds; D001597:Benzylidene Compounds; C468773:GW 4869; D018793:Interleukin-13