title: Effects of Epstein-Barr virus on the development of dendritic cells derived from cord blood monocytes: an essential role for apoptosis.
abstract: OBJECTIVE
  Epstein-Barr virus (EBV) is a ubiquitous human γ-herpes virus, which can adapt and evade host immune defense. Dendritic cells (DCs) play a pivotal role in the initiation and maintenance of immune responses. This study investigated the effects of EBV on cord blood monocytes derived DCs (CBDC).
  
  
  METHODS
  Monocytes were isolated from cord blood and cultured in medium containing recombinant IL-4 and GM-CSF to induce DCs development. B95-8 supernatant was added in monocytes culture medium for EBV infection at day 0. Phenotypic characterization of DCs, apoptotic cells, and mitochondrial membrane potential (MMP) were detected by flow cytometry. The morphology was observed by Hoechst 33258 staining and TUNEL staining, the expression of X-linked inhibitor of apoptosis protein (XIAP) was detected by Western blotting assay and caspase 3, 8 and 9 activity was measured.
  
  
  RESULTS
  Phenotypic characterization of DCs was changed in EBV-treated group. Chromatin condensation and DNA fragmentation were observed in EBV induced CBDC apoptosis. In addition, caspase 3, caspase 8, and caspase 9 activation were enhanced in the EBV-treated group. This was accompanied by the loss of MMP. Furthermore, XIAP expression was down-regulated in the EBV-treated group and compared to mock-infected group.
  
  
  CONCLUSIONS
  These results suggested that EBV could inhibit CBDC phenotypic differentiation, and induce CBDC apoptosis in caspase-dependent manner with involvement of the mitochondrial pathway. This might help EBV to evade host immune responses to establish persistent infection.
authors.affiliation: Department of Clinical Immunology, Children's Hospital of Shanghai, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Wang
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Li
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Jin
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.forename: Tong-Xin
authors.initials: TX
authors.lastname: Chen
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D020169:Caspases / Q000276:immunology; D002454:Cell Differentiation; D003588:Cytopathogenic Effect, Viral / Q000502:physiology*; D003713:Dendritic Cells / Q000473:pathology* / Q000821:virology; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D004854:Herpesvirus 4, Human / Q000276:immunology / Q000502:physiology*; D006801:Humans; D015847:Interleukin-4 / Q000276:immunology; D009000:Monocytes / Q000166:cytology / Q000473:pathology* / Q000821:virology; D010641:Phenotype; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000276:immunology
chemical_list: D051636:X-Linked Inhibitor of Apoptosis Protein; D015847:Interleukin-4; D020169:Caspases