title: Cross-linking of CD80 and CD86 Diminishes Expression of CD54 on EBV-transformed B Cells through Inactivation of RhoA and Ras.
abstract: BACKGROUND
  Epstein Barr virus (EBV) infected B cells are transformed into lymphoblastoid cell lines. Some researchers suggested some a few similarities between this process and carcinogenesis. We observed the expression of CD80 and CD86, co-stimulatory molecules on EBV-transformed B cells and changes of CD54 expression after stimulation of CD80 and CD86.
  
  
  METHODS
  CD80 and CD86 were stimulated using anti-CD80 and anti-CD86 monoclonal antibodies. To assess apoptosis and surface protein expression, flow cytometric analysis was performed. Intracellular signal molecules were evaluated by RT-PCR and immunoblot. Morphology and localization of proteins were examined using inverted or confocal microscope.
  
  
  RESULTS
  Cross-linking of CD80 and CD86 induced apoptosis and interfered with proliferation of EBV-transformed B cells, and dispersion of clumped cells. We also examined that their stimulation induced ROS accumulation and reduced CD54 expression. Interestingly, we observed that CD80 and CD86 diminished the expression of CD54 in different methods. Both CD80 and CD86 down-regulated activation of focal adhesion kinase. CD80 stimulus inhibited CD54 expression through mainly RhoA inactivation, while CD86 down-regulated Ras and JNK phosphorylation.
  
  
  CONCLUSIONS
  These results suggest that co-stimulatory CD80 and CD86 molecules, expressed EBV-transformed B cells, may play a role in apoptosis and cell adhesion.
authors.affiliation: Department of Anatomy and Research Center for Tumor Immunology, Inje University College of Medicine, Busan 614-735, Korea.
authors.forename: Ga Bin
authors.initials: GB
authors.lastname: Park
authors.forename: Yeong Seok
authors.initials: YS
authors.lastname: Kim
authors.forename: Hyunkeun
authors.initials: H
authors.lastname: Song
authors.forename: Seonghan
authors.initials: S
authors.lastname: Kim
authors.forename: Dong Man
authors.initials: DM
authors.lastname: Park
authors.forename: Wang Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Dae Young
authors.initials: DY
authors.lastname: Hur