title: Lymphocyte-derived microparticles induce bronchial epithelial cells' pro-inflammatory cytokine production and apoptosis.
abstract: OBJECTIVE
  The aim of this study was to determine if human CEM (human lymphoblastoma) T cell-derived microparticles (LMPs) could directly induce human bronchial epithelial cells (BECs) apoptosis and cytokine production. We also tested if LMPs phagocytosis by BECs played a role in mediating these effects.
  
  
  METHODS
  We generated LMPs from CEM (human lymphoblastoma) T cells to investigate their effects on a human BEC cell line (16HBE) in vitro.
  
  
  RESULTS
  BECs (16HBE cells) incubation with LMPs resulted in significant production of inflammation-associated cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and IL-8, in a dose- and time-dependent manner. LMPs also induced increased activities of caspase-3, caspase-8, and caspase-9 in BECS, which resulted in increased BECs apoptosis as assessed by flow cytometry (Annexin V and propidium iodide staining) and transmission electronic microscopy (TEM). Interestingly, LMPs effects on BECS were inhibited by the phagocytosis inhibitors cytochalasin D and chloroquine.
  
  
  CONCLUSIONS
  These results suggest that phagocytosis plays an important role in mediating the effects of LMPs on BECs. Thus, increased LMP concentrations may contribute to increased respiratory inflammatory responses and innate immune response maintenance in airway epithelium after LMPs engulfment by endothelial cells.
authors.affiliation: Department of Pulmonology, Chongqing Southwest Hospital, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Qiu
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.forename: Chun
authors.initials: C
authors.lastname: Yang
authors.forename: Carmen
authors.initials: C
authors.lastname: Gagnon
authors.forename: Pierre
authors.initials: P
authors.lastname: Hardy
mesh_terms: D017209:Apoptosis / Q000276:immunology*; D001980:Bronchi / Q000166:cytology* / Q000276:immunology* / Q000473:pathology; D002460:Cell Line; D049109:Cell Proliferation; D055252:Cell-Derived Microparticles / Q000276:immunology* / Q000648:ultrastructure; D016207:Cytokines / Q000096:biosynthesis* / Q000502:physiology; D006801:Humans; D007113:Immunity, Innate; D007249:Inflammation / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D010587:Phagocytosis / Q000276:immunology; D020545:Respiratory Mucosa / Q000166:cytology / Q000276:immunology* / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology* / Q000648:ultrastructure
chemical_list: D016207:Cytokines