Peptide P60

Peptide P60 is a FOXP3 inhibitor. Peptide P60 reduces the nuclear translocation of FOXP3 and impairs FOXP3-mediated inhibition of NF-κB and NFAT activity. Peptide P60 inhibits the immunosuppressive activity of regulatory T cells and restores the proliferation and activation of effector T cells. Peptide P60 induces lymphoproliferative autoimmune syndrome in neonatal ICR mice and reduces the number of CD4⁺CD25⁺Foxp3⁺ T cells in the spleen. Peptide P60 enhances the efficacy of AH1 (HY-P4193) peptide vaccine and recombinant adenovirus-based HCV NS3 vaccine in BALB/c mice, including protective effects against CT26 tumor implantation. Peptide P60 can be used in studies related to tumor immunity, viral infection and lymphoproliferative autoimmune syndrome^[1]. In Vitro:Peptide P60 (5 μM; 60 s association, 30 s dissociation) specifically binds to recombinant human FOXP3 protein in cell-free surface plasmon resonance assays^[1].
Peptide P60 (10 μM; 2-18 min) can enter live Jurkat T cells, with its intracellular accumulation detectable within 2 min and reaching a peak at 10 min of incubation^[1].
Peptide P60 (100 μM; 24 h) inhibits the nuclear translocation of transiently transfected FOXP3 in human embryonic kidney 293 cells, partially restores the NF-κB transcriptional activity suppressed by FOXP3 overexpression in human embryonic kidney 293 cells, and rescues the NFAT transcriptional activity inhibited by FOXP3 overexpression in Jurkat T cells^[1].
Peptide P60 (100 μM; 3 days) inhibits the suppressive function of murine or human CD4⁺CD25⁺ regulatory T cells (Tregs), restores the proliferation of CD4⁺CD25⁻ effector T cells from BALB/c mice stimulated with anti-CD3 antibody, and restores the proliferation of human peripheral blood mononuclear cells (PBMCs) stimulated with anti-CD3/CD28 magnetic beads^[1].
Peptide P60 (100 μM; 3 days) inhibits the suppressive function of mouse or human CD4⁺CD25⁺ Treg cells, restores the proliferation of BALB/c mouse effector T cells in mixed lymphocyte reactions with C57BL/6 dendritic cells, and restores the proliferation of human peripheral blood mononuclear cells (PBMCs) in mixed lymphocyte reactions^[1].
Peptide P60 (100 μM; 48 h) modulates gene expression in human CD4⁺CD25⁻ effector T cells stimulated by anti-CD3, reduces the mRNA levels of Foxp3 and IL-10, and increases the mRNA level of IFN-γ^[1].
Peptide P60 (100 μM; 48 h) upregulates IL-2 mRNA expression in human CD4⁺CD25⁺ regulatory T cells (Tregs) stimulated with IL-2 + anti-CD3, without altering the mRNA levels of Foxp3 or IFN-γ^[1]. In Vivo:Peptide P60 (25 nM/mouse; i.p.; daily; day 1 to 10 after birth) induces fatal, scurfy syndrome-like lymphoproliferative autoimmune disease in neonatal ICR mice, accompanied by a reduction in splenic CD4⁺CD25⁺Foxp3⁺ T cells and persistent inflammatory injury^[1].
When administered in combination with the AH1 peptide vaccine, Peptide P60 (50 nM/mouse; i.p.; daily; days 0-9 post immunization) increases the tumor-free survival rate of BALB/c mice challenged with CT26 colorectal cancer cells to 82%^[1].
When administered in combination with the RAdNS3 vaccine, Peptide P60 (50 nM/mouse; i.p.; daily; days 0-10 after immunization) provides complete protection against recombinant vaccinia virus HCV challenge in BALB/c mice^[1].