Objective To observe if VIR576,an 20-mer peptide derived from the C-proximal subfragment of a1-antitrypsin(a1-AT)which inhibits human immunodeficiency virus type 1(HIV-1)entry into the target cells by interacting with...Objective To observe if VIR576,an 20-mer peptide derived from the C-proximal subfragment of a1-antitrypsin(a1-AT)which inhibits human immunodeficiency virus type 1(HIV-1)entry into the target cells by interacting with fusion peptide(FP),can also directly inhibit CD4^(+)T cell activation in vitro.Methods Splenocytes isolated from DO11.10 OVA Tg mice were stimulated with ovalbumin or concanavalin A to test the effects of VIR576 on antigen-specific or non-antigen-specific T cell activation.Both primary CD4^(+)CD25-T cells from DO11.10 mice and CD4^(+)T cell line A2b were activated with specific antigens to evaluate the effects of VIR576.Results VIR576 inhibited antigen-specific splenocyte activation but had no significant effect on non-antigen-specific T-cell activation,which bypassed the crosstalk between the CD3-signaling complex and TCR.We furthermore observed that VIR576 could also down-regulate antigen-specific CD4^(+)T-cell activation.Conclusion Given the high susceptibility of activated CD4^(+)T cells in the mucosa to HIV-1 infection,the inhibitory effects of VIR576 on both HIV entry into the target cells and CD4^(+)T-cell activation suggest the potential of VIR576 as a microbicide for prevention of sexual transmission of HIV.展开更多
Aim To determine the effect of VIR576, a dimeric 20-mer peptide potently inhibits HIV-1 entry, on antigen-specific T cell and non-antigen-specific T cell activation. Methods In vitro T-cell proliferation assays were e...Aim To determine the effect of VIR576, a dimeric 20-mer peptide potently inhibits HIV-1 entry, on antigen-specific T cell and non-antigen-specific T cell activation. Methods In vitro T-cell proliferation assays were estalished to investigate the potential effect of FP16, VIR576 on the proliferation of A2b cells in response to MOG35-55. A fluorescence-based binding assay using Rhodamine （Rho）-conjugated VIR576 was estalished to e- valuate the potential interaction between VIR576 and TCR-TMD. Fluorescence confocal microscopy was used to to study whether VIR576 could colocalize with CD4 molecule in the CD4 ＋ T cell membrane to interact with TCR. Re- suits The effects of VIR576 on the proliferation of MOG-specific A2b T cells in response to the stimulation of MOG 35 -55 peptide wasevaluated. VIR576 itself could directly inhibit antigen-specific T-cell activation. Further studies confirmed that VIR576 also inhibited the proliferation of splenocytes and primary CD4 ＋ CD25- T cells iso- lated from the spleens of DOll. 10 OVA Tg mice in response to OVA stimulation in vitro. However, VIR576 had no effect on the proliferation of normal mouse splenocytes and T lymphocytes stimulated with Con A or anti-CD3 anti- body. The FRET assay confirmed that VIR576 effectively binds to the core peptide （CP） , corresponding to the N- terminal 9-residue region of TCR-TMD. Confocal microscopy revealed that VIR576 colocalizes with CD4 on the ac- tivated CD4 ＋ T-cell membrane, particularly within the activation cluster including re-assembled CD4 and TCR mol- ecules. Conclusion These results suggest that VIR576 is effective in suppressing antigen-specific T-cell activa- tion, but it has no effect on non-specific T-cell proliferation, and VIR576 has the ability to down-regulate antigen- specific T-cell activation by interaction with TCR transmembrane domain.展开更多
Kaposi sarcoma-associated herpesvirus(KSHV) is necessary but not sufficient to cause Kaposi sarcoma(KS).Coinfection with human immunodeficiency virus type 1(HIV-1), in the absence of antiretroviral suppressive therapy...Kaposi sarcoma-associated herpesvirus(KSHV) is necessary but not sufficient to cause Kaposi sarcoma(KS).Coinfection with human immunodeficiency virus type 1(HIV-1), in the absence of antiretroviral suppressive therapy, drastically increases the risk of KS.Previously, we identified that HIV-1 transactivative transcription protein(Tat) was an important cofactor that activated lytic cycle replication of KSHV.Here, we further investigated the potential of Tat to influence tumorigenesis induced by KSHV Kaposin A, a product of KSHV that was encoded by the open reading frame K12(a KSHV-transforming gene).By using colony formation in soft agar, H-3-TdR incorporation, cell cycle, and microarray gene expression analyses, we demonstrated that Tat enhanced proliferation as well as mitogen-activated protein kinase, signal transducer and activator of transcription 3, and phosphatidylinositol 3-kinase/protein kinase B signaling induced by Kaposin A in NIH3T3 cells.Animal experiments further demonstrated that Tat accelerated tumorigenesis by Kaposin A in athymic nu/nu mice.Cells obtained from primary tumors of nude mice succeeded inducing tumors in immunocompetent mice.These data suggest that Tat can accelerate tumorigenesis induced by Kaposin A.Our data present the first line of evidence that Tat may participate in KS pathogenesis by collaborating with Kaposin A in acquired immunodeficiency syndrome(AIDS)-related KS(AIDS-KS) patients.Our data also suggest that the model for Kaposin and Tat-mediated oncogenesis will contribute to our understanding of the pathogenesis of AIDS-KS at the molecular level and may even be important in exploring a novel therapeutic method for AIDS-KS.展开更多
OBJECTIVE To evaluate whether the IDO1 inhibitor 1-methyl-L-tryptophan(1-MT)combine calcium influx inhibitor carboxyamidotriazole(CAI)could further enhance the suppression of programmed death 1(PD-1)in CD8^+T cells an...OBJECTIVE To evaluate whether the IDO1 inhibitor 1-methyl-L-tryptophan(1-MT)combine calcium influx inhibitor carboxyamidotriazole(CAI)could further enhance the suppression of programmed death 1(PD-1)in CD8^+T cells and investigate the curative effect of the combined use.METHODS CD8^+T cells were isolated from normal mice spleen by negative selection using magnetic cell separation.The isolated CD8^+T cells were cultured in RPMI 1640 medium containing 10%FBS and 100 U·mL^(-1)IL-2 and activated by the addition of anti-CD3 and anti-CD28(1 g·L^(-1) each mabs).CD8^+T cells were pretreated for 48 h with drug and the fluo-3 as a marker of intracellular calcium concentration was detected by flow cytometry.The calcineurin(Ca N)levels were assayed with ELISA in CD8^+T cells after 48 h incubation with 10μm CAI.The nuclear translocations of NFAT and AHR were detected by immunofluorescent staining after 48 h of drug treatment.The expression of PD-1 in CD8^+T cells was analyzed by flow cytometry.RESULTS Intracellular fluorescent intensity was markedly debase due to CAI treatment(P<0.01).Meanwhile,the changes of CaN content had a resembled correlation(P<0.01).Immunofluorescence experiment showed that after combination therapy the transfer of NFAT and AHR in nuclear substantially reduced.Flow cytometry revealed that after the combination caused a significant decrease in PD-1 expression in CD8^+T cells.CONCLUSION CAI and 1-MT could inhibit markedly the expression of PD-1 in CD8^+T cells by inhibiting the nuclear translocation of NFAT and AHR,respectively and the combination of them has synergetic effect.展开更多
基金Supported by National Natural Science Foundation of China(30672496 and 30801413)Guangdong Medical Research Grant(A201032)Guangdong International Cooperation Grant(2011B050200006)
文摘Objective To observe if VIR576,an 20-mer peptide derived from the C-proximal subfragment of a1-antitrypsin(a1-AT)which inhibits human immunodeficiency virus type 1(HIV-1)entry into the target cells by interacting with fusion peptide(FP),can also directly inhibit CD4^(+)T cell activation in vitro.Methods Splenocytes isolated from DO11.10 OVA Tg mice were stimulated with ovalbumin or concanavalin A to test the effects of VIR576 on antigen-specific or non-antigen-specific T cell activation.Both primary CD4^(+)CD25-T cells from DO11.10 mice and CD4^(+)T cell line A2b were activated with specific antigens to evaluate the effects of VIR576.Results VIR576 inhibited antigen-specific splenocyte activation but had no significant effect on non-antigen-specific T-cell activation,which bypassed the crosstalk between the CD3-signaling complex and TCR.We furthermore observed that VIR576 could also down-regulate antigen-specific CD4^(+)T-cell activation.Conclusion Given the high susceptibility of activated CD4^(+)T cells in the mucosa to HIV-1 infection,the inhibitory effects of VIR576 on both HIV entry into the target cells and CD4^(+)T-cell activation suggest the potential of VIR576 as a microbicide for prevention of sexual transmission of HIV.
文摘Aim To determine the effect of VIR576, a dimeric 20-mer peptide potently inhibits HIV-1 entry, on antigen-specific T cell and non-antigen-specific T cell activation. Methods In vitro T-cell proliferation assays were estalished to investigate the potential effect of FP16, VIR576 on the proliferation of A2b cells in response to MOG35-55. A fluorescence-based binding assay using Rhodamine （Rho）-conjugated VIR576 was estalished to e- valuate the potential interaction between VIR576 and TCR-TMD. Fluorescence confocal microscopy was used to to study whether VIR576 could colocalize with CD4 molecule in the CD4 ＋ T cell membrane to interact with TCR. Re- suits The effects of VIR576 on the proliferation of MOG-specific A2b T cells in response to the stimulation of MOG 35 -55 peptide wasevaluated. VIR576 itself could directly inhibit antigen-specific T-cell activation. Further studies confirmed that VIR576 also inhibited the proliferation of splenocytes and primary CD4 ＋ CD25- T cells iso- lated from the spleens of DOll. 10 OVA Tg mice in response to OVA stimulation in vitro. However, VIR576 had no effect on the proliferation of normal mouse splenocytes and T lymphocytes stimulated with Con A or anti-CD3 anti- body. The FRET assay confirmed that VIR576 effectively binds to the core peptide （CP） , corresponding to the N- terminal 9-residue region of TCR-TMD. Confocal microscopy revealed that VIR576 colocalizes with CD4 on the ac- tivated CD4 ＋ T-cell membrane, particularly within the activation cluster including re-assembled CD4 and TCR mol- ecules. Conclusion These results suggest that VIR576 is effective in suppressing antigen-specific T-cell activa- tion, but it has no effect on non-specific T-cell proliferation, and VIR576 has the ability to down-regulate antigen- specific T-cell activation by interaction with TCR transmembrane domain.
基金This study was partially supported by a grant from the ministry of HealthL abor and Welfare of Japan+1 种基金Hum an Genom e and Regenerative Medicine Project (ChairpersonHidehiko Saito)
文摘Kaposi sarcoma-associated herpesvirus(KSHV) is necessary but not sufficient to cause Kaposi sarcoma(KS).Coinfection with human immunodeficiency virus type 1(HIV-1), in the absence of antiretroviral suppressive therapy, drastically increases the risk of KS.Previously, we identified that HIV-1 transactivative transcription protein(Tat) was an important cofactor that activated lytic cycle replication of KSHV.Here, we further investigated the potential of Tat to influence tumorigenesis induced by KSHV Kaposin A, a product of KSHV that was encoded by the open reading frame K12(a KSHV-transforming gene).By using colony formation in soft agar, H-3-TdR incorporation, cell cycle, and microarray gene expression analyses, we demonstrated that Tat enhanced proliferation as well as mitogen-activated protein kinase, signal transducer and activator of transcription 3, and phosphatidylinositol 3-kinase/protein kinase B signaling induced by Kaposin A in NIH3T3 cells.Animal experiments further demonstrated that Tat accelerated tumorigenesis by Kaposin A in athymic nu/nu mice.Cells obtained from primary tumors of nude mice succeeded inducing tumors in immunocompetent mice.These data suggest that Tat can accelerate tumorigenesis induced by Kaposin A.Our data present the first line of evidence that Tat may participate in KS pathogenesis by collaborating with Kaposin A in acquired immunodeficiency syndrome(AIDS)-related KS(AIDS-KS) patients.Our data also suggest that the model for Kaposin and Tat-mediated oncogenesis will contribute to our understanding of the pathogenesis of AIDS-KS at the molecular level and may even be important in exploring a novel therapeutic method for AIDS-KS.
基金supported by National Natural Science Foundation of China(81402943)CAMS Major Collaborative Innovation Project(2016-I2M-1-011)PUMC Youth Fund(3332015168)
文摘OBJECTIVE To evaluate whether the IDO1 inhibitor 1-methyl-L-tryptophan(1-MT)combine calcium influx inhibitor carboxyamidotriazole(CAI)could further enhance the suppression of programmed death 1(PD-1)in CD8^+T cells and investigate the curative effect of the combined use.METHODS CD8^+T cells were isolated from normal mice spleen by negative selection using magnetic cell separation.The isolated CD8^+T cells were cultured in RPMI 1640 medium containing 10%FBS and 100 U·mL^(-1)IL-2 and activated by the addition of anti-CD3 and anti-CD28(1 g·L^(-1) each mabs).CD8^+T cells were pretreated for 48 h with drug and the fluo-3 as a marker of intracellular calcium concentration was detected by flow cytometry.The calcineurin(Ca N)levels were assayed with ELISA in CD8^+T cells after 48 h incubation with 10μm CAI.The nuclear translocations of NFAT and AHR were detected by immunofluorescent staining after 48 h of drug treatment.The expression of PD-1 in CD8^+T cells was analyzed by flow cytometry.RESULTS Intracellular fluorescent intensity was markedly debase due to CAI treatment(P<0.01).Meanwhile,the changes of CaN content had a resembled correlation(P<0.01).Immunofluorescence experiment showed that after combination therapy the transfer of NFAT and AHR in nuclear substantially reduced.Flow cytometry revealed that after the combination caused a significant decrease in PD-1 expression in CD8^+T cells.CONCLUSION CAI and 1-MT could inhibit markedly the expression of PD-1 in CD8^+T cells by inhibiting the nuclear translocation of NFAT and AHR,respectively and the combination of them has synergetic effect.
