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
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
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.
