AIM:To explore the possibility and mechanism of inhibiting allogeneic T-cell responses by Kupffer cells (KC)pretreated with interferon-γ(IFN-γ)in vitro. METHODS:The expressions of indoleamine 2,3-dioxygenase(IDO)mRN...AIM:To explore the possibility and mechanism of inhibiting allogeneic T-cell responses by Kupffer cells (KC)pretreated with interferon-γ(IFN-γ)in vitro. METHODS:The expressions of indoleamine 2,3-dioxygenase(IDO)mRNA and FasL mRNA in KC pretreated with IFN-γwere studied with real-time polymerase chain reaction(PCR).The catabolism of tryptophan by IDO from KC was analyzed by high performance liquid chromatography.Allogeneic T-cell response was used to confirm the inhibition of KC in vitro.The proliferation of lymphocytes was detected using[ 3 H]thymidine incorporation.Cell cycle and lymphocyte apoptosis were evaluated by flow cytometric assay. RESULTS:Real-time PCR revealed IDO mRNA and FasL mRNA expressions in KC pretreated with IFN-γ,and IDO catabolic effect was confirmed by a decrease in tryptophan and increase in kynurenine concentration. KC expressing IDO and FasL in BABL/c mice acquired the ability to suppress the proliferation of T-cells from C57BL/6,which could be blocked by addition of 1-methyl-tryptophan and anti-FasL antibody.KC expressing IDO could induce allogeneic T-cell apoptosisCONCLUSION:In addition to Fas/FasL pathway,IDO may be another mechanism for KC to induce immune tolerance.展开更多
基金Supported by Natural Science Foundation of Fujian Province,No.2007J0073Young Talents Innovation Foundation of Fujian Province,No.2006F3033
文摘AIM:To explore the possibility and mechanism of inhibiting allogeneic T-cell responses by Kupffer cells (KC)pretreated with interferon-γ(IFN-γ)in vitro. METHODS:The expressions of indoleamine 2,3-dioxygenase(IDO)mRNA and FasL mRNA in KC pretreated with IFN-γwere studied with real-time polymerase chain reaction(PCR).The catabolism of tryptophan by IDO from KC was analyzed by high performance liquid chromatography.Allogeneic T-cell response was used to confirm the inhibition of KC in vitro.The proliferation of lymphocytes was detected using[ 3 H]thymidine incorporation.Cell cycle and lymphocyte apoptosis were evaluated by flow cytometric assay. RESULTS:Real-time PCR revealed IDO mRNA and FasL mRNA expressions in KC pretreated with IFN-γ,and IDO catabolic effect was confirmed by a decrease in tryptophan and increase in kynurenine concentration. KC expressing IDO and FasL in BABL/c mice acquired the ability to suppress the proliferation of T-cells from C57BL/6,which could be blocked by addition of 1-methyl-tryptophan and anti-FasL antibody.KC expressing IDO could induce allogeneic T-cell apoptosisCONCLUSION:In addition to Fas/FasL pathway,IDO may be another mechanism for KC to induce immune tolerance.
