title: FasL expression in hepatic antigen-presenting cells and phagocytosis of apoptotic T cells by FasL+ Kupffer cells are indicators of rejection activity in human liver allografts.
abstract: Fas-Fas ligand (FasL) interaction and apoptosis are important in the mechanism of allograft rejection. However, the interaction between donor and recipient cells, specifically focusing on antigen-presenting cells (APCs), under various conditions is poorly understood in human liver allografts. FasL expression on APCs, its association with apoptosis, and the origin of apoptotic lymphocytes in human liver allografts were assessed by immunohistochemistry and in situ hybridization. We found increased expression of FasL on Kupffer cells (KCs) and endothelium in acute cellular rejection (n = 20) and to lesser extent in chronic rejection (n = 6) and septic cholangitis (n = 5) compared with stable grafts and normal controls. In addition, the graft specificity of infiltrating T cells was confirmed by polymerase chain reaction examination of T-cell receptor-gamma loci. T-cell apoptosis occurred at a higher rate in acute cellular rejection than in chronic rejection or septic cholangitis. The number of apoptotic bodies derived from recipient lymphocytes correlated with the severity of rejection and was reversed by treatment. FasL(+) KCs phagocytosed CD4(+) interferon-gamma(+) T cells, rather than CD4(+) interleukin-4(+) T cells, suggesting a role of KCs in regulating CD4(+) T-cell subset differentiation. In conclusion, our data suggest that FasL expression on APCs and phagocytosis of apoptotic T cells by FasL(+) KCs are indicators of rejection activity in human liver allografts.
authors.affiliation: Department of Diagnostic Pathology, Kyoto University Hospital, Kyoto, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Miyagawa-Hayashino
authors.forename: Tatsuaki
authors.initials: T
authors.lastname: Tsuruyama
authors.forename: Hiroto
authors.initials: H
authors.lastname: Egawa
authors.forename: Hironori
authors.initials: H
authors.lastname: Haga
authors.forename: Hiromi
authors.initials: H
authors.lastname: Sakashita
authors.forename: Tomoko
authors.initials: T
authors.lastname: Okuno
authors.forename: Shinya
authors.initials: S
authors.lastname: Toyokuni
authors.forename: Keiji
authors.initials: K
authors.lastname: Tamaki
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Yamabe
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Manabe
authors.forename: Shinji
authors.initials: S
authors.lastname: Uemoto
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology*; D017209:Apoptosis; D002675:Child, Preschool; D053222:Fas Ligand Protein / Q000378:metabolism*; D006084:Graft Rejection / Q000276:immunology*; D006801:Humans; D007728:Kupffer Cells / Q000378:metabolism / Q000502:physiology*; D016031:Liver Transplantation / Q000276:immunology*; D010587:Phagocytosis; D013601:T-Lymphocytes / Q000276:immunology*; D014184:Transplantation, Homologous; D019014:fas Receptor / Q000378:metabolism