title: [Effects of natural killer cells stimulated with immobilized MHC class I chain-related antigen A on activities of dendritic cells].
abstract: OBJECTIVE
  To observe the effects of NK cells stimulated with immobilized MHC class I chain-related antigen A (iMICA) on activities of dendritic cells (DCs).
  
  
  METHODS
  Firstly fresh allogeneic NK cells, or iMICA-stimulated allogeneic NK cells, and autologous NK cells stimulated with IL-2 or IL-2 and iMICA were co-cultured with immature DCs (iDCs) at the ratio of 5:1 for 24 hours. Frequencies of HLA-DR positive or CD86 positive DCs were detected by flow cytometry. Next autologous NK cells stimulated with iMICA were co-cultured with iDCs at the ratio of 1:5 for 24 hours. Variation of HLA-DR or CD86 expression on dendritic cells was measured. Lastly IFN-γ neutralizing antibody was added into the NK-DCs co-culture system to observe HLA-DR or CD86 expression on DCs.
  
  
  RESULTS
  When NK:iDCs ratio was 5:1, both fresh allogeneic and activated autologous NK cells killed iDCs efficiently. iMICA did not synergize this cytotoxicity. However, when NK:iDCs ratio was 1:5, NK cells activated by iMICA promoted HLA-DR and CD86 expression on DCs. IFN-γ antibody down-regulated HLA-DR and CD86 expression on DCs which were co-cultured with iMICA-activated NK cells.
  
  
  CONCLUSIONS
  iMICA is redundant as fresh allogeneic or activated autologous NK cells killed iDCs. However, if numbers of NK cell are less than those of DCs, iMICA can stimulate NK cells to produce IFN-γ for DCs maturation.
authors.affiliation: Department of Immunology, Medical College, the Second Affiliated Hospital, Yangzhou University, Yangzhou 225001, China. wjgong@yzu.edu.cn
authors.forename: Wei-juan
authors.initials: WJ
authors.lastname: Gong
authors.forename: Chun-xiang
authors.initials: CX
authors.lastname: Gong
authors.forename: Ti
authors.initials: T
authors.lastname: Yang
authors.forename: Wei-ming
authors.initials: WM
authors.lastname: Xiao
authors.forename: Li
authors.initials: L
authors.lastname: Qian
authors.forename: Ming-chun
authors.initials: MC
authors.lastname: Ji
mesh_terms: D018920:Coculture Techniques; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D006684:HLA-DR Antigens / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000494:pharmacology*; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*
chemical_list: D006684:HLA-DR Antigens; D015395:Histocompatibility Antigens Class I; D007376:Interleukin-2; C099187:MHC class I-related chain A