title: Inhibition of T-cell expansion caused by inducible costimulator/B7h costimulation blockade in direct allorecognition pathway.
abstract: OBJECTIVE
  Inducible costimulator (ICOS)/B7h costimulation plays a crucial role in acute and chronic allograft rejection. To test the role of the ICOS signal in T-cell activation and expansion, we used ICOS-Fc-targeted B cells as donor antigen presenting cells to challenge the allogeneic response in vitro.
  
  
  METHODS
  In vitro, the binding of ICOS-Fc with B7h on splenic B cells was confirmed by flow cytometry analysis. To evaluate the capacity of ICOS-Fc-targeted B cells to elicit an allogeneic response in vitro, we performed mixed lymphocyte reactions.
  
  
  RESULTS
  The binding of B7h on splenic B cells by ICOS-Fc was confirmed at a saturating concentration of 100 μg/mL. Blockade of ICOS/B7h in direct allorecognition depressed proliferation of alloreactive T cells in vitro.
  
  
  CONCLUSIONS
  ICOS/B7h signal plays an important role in direct allorecognition, eliciting allogeneic responses in vitro.
authors.affiliation: Department of General Surgery, General Hospital of Beijing Military Command, Beijing, China.
authors.forename: J F
authors.initials: JF
authors.lastname: Du
authors.forename: Q-Y
authors.initials: QY
authors.lastname: Li
authors.forename: X Q
authors.initials: XQ
authors.lastname: Ji
authors.forename: G
authors.initials: G
authors.lastname: Chen
authors.forename: X
authors.initials: X
authors.lastname: Bai
authors.forename: F-Y
authors.initials: FY
authors.lastname: Zuo
authors.forename: B
authors.initials: B
authors.lastname: Yu
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D005434:Flow Cytometry; D007141:Immunoglobulin Fc Fragments / Q000378:metabolism; D060945:Inducible T-Cell Co-Stimulator Ligand / Q000378:metabolism*; D060889:Inducible T-Cell Co-Stimulator Protein / Q000378:metabolism*; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: C556694:Icos protein, mouse; C400230:Icosl protein, mouse; D007141:Immunoglobulin Fc Fragments; D060945:Inducible T-Cell Co-Stimulator Ligand; D060889:Inducible T-Cell Co-Stimulator Protein