RESUMO
Multivalent synthetic vaccines were obtained by solid-phase synthesis of tumor-associated MUC1 glycopeptide antigens and their coupling to a Pam3 Cys lipopeptide through click reactions. These vaccines elicited immune responses in mice without the use of any external adjuvant. The vaccine containing four copies of a MUC1 sialyl-TN antigen showed a significant cluster effect. It induced in mice prevailing IgG2a antibodies, which bind to MCF-7 breast tumor cells and initiate the killing of these tumor cells by activation of the complement-dependent cytotoxicity complex.
Assuntos
Vacinas Anticâncer/imunologia , Glicopeptídeos/química , Lipoproteínas/química , Mucina-1/química , Sequência de Aminoácidos , Animais , Anticorpos/imunologia , Anticorpos/farmacologia , Apoptose/efeitos dos fármacos , Vacinas Anticâncer/síntese química , Vacinas Anticâncer/química , Química Click , Epitopos de Linfócito T/química , Epitopos de Linfócito T/imunologia , Glicopeptídeos/síntese química , Humanos , Lipoproteínas/síntese química , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Mucina-1/imunologia , Mucina-1/metabolismo , CoelhosRESUMO
The T-helper epitope peptide P30 (green in the scheme) from tetanus toxoid was used as the immunostimulant in MUC1 glycopeptide antitumor vaccines and apparently also acts as a built-in adjuvant. P30-conjugated glycopeptide vaccines containing three glycans in the immunodominant motifs PDTRP and GSTAP induced much stronger immune responses and complement dependent cytotoxicity mediated killing of tumor cells when applied in plain PBS solution without complete Freund's adjuvant.
Assuntos
Vacinas Anticâncer/química , Epitopos de Linfócito T/imunologia , Epitopos/imunologia , Mucina-1/química , Toxoide Tetânico/imunologia , Epitopos de Linfócito B/imunologia , Glicopeptídeos , Humanos , Mucina-1/imunologia , PeptídeosRESUMO
The differences in the C-terminal domains of human amylin peptide variants initiate different aggregation processes and differences in the composition of the aggregates by affecting the hydrophobic cores, conformations, and intra-sheet interactions of the peptides, which have distinct effects on the cytotoxicity of the peptides.
Assuntos
Antineoplásicos/farmacologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/farmacologia , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Interações Hidrofóbicas e Hidrofílicas , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Conformação Proteica , Ratos , Relação Estrutura-AtividadeRESUMO
The pathogenesis of type II diabetes can be linked to cosecreted hIAPP/insulin interacting with cell membranes. Here we investigate the nanostructures by co-assembling hIAPP and insulin on surfaces. By tuning the hIAPP/insulin ratio, atomic force microscopy reveals the resulting nanostructure morphology changes from fibrils to oligomers, to annular. Implications for in vivo studies are discussed.
Assuntos
Amiloide/ultraestrutura , Diabetes Mellitus Tipo 2/metabolismo , Insulina/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Amiloide/metabolismo , Diabetes Mellitus Tipo 2/patologia , Humanos , Microscopia de Força AtômicaRESUMO
Abnormal assembly of monomeric beta-amyloid (Abeta) in Alzheimer's disease leads to the formation of most neurotoxic oligomers in vivo. In this study, we explored a linking strategy to design hybrid peptides, by combining the Abeta recognition motif and the solvent disruptive sequences. We found that in vitro all synthetic peptides with the recognition motif can affect Abeta fibrillization and alter the morphology of Abeta aggregates variously, different from those without the recognition motif. The effects of peptides containing recognition motif on Abeta aggregation correlate with their abilities to change the surface tension of solutions. In addition, compounds with the recognition motif, not those without such motif, can inhibit cytotoxicity of Abeta in cell culture probably by decreasing the amount of toxic Abeta oligomers. These results indicate that recognition domain and solvent effect should be considered as important factors when designing molecules to target Abeta aggregation.
Assuntos
Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/toxicidade , Neurônios/efeitos dos fármacos , Peptídeos/química , Peptídeos/farmacologia , Multimerização Proteica/efeitos dos fármacos , Motivos de Aminoácidos , Sequência de Aminoácidos , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/ultraestrutura , Animais , Linhagem Celular Tumoral , Camundongos , Microscopia Eletrônica de Transmissão , Dados de Sequência MolecularRESUMO
Decelerated degradation of beta-amyloid (Abeta) and its interaction with synaptic copper may be pathogenic in Alzheimer disease. Recently, Co(III)-cyclen tagged to an aromatic recognition motif was shown to degrade Abeta in vitro. Here, we report that apocyclen attached to selective Abeta recognition motifs (KLVFF or curcumin) can capture copper bound to Abeta and use the Cu(II) in place of Co(III) to become proteolytically active. The resultant complexes interfere with Abeta aggregation, degrade Abeta into fragments, preventing H2O2 formation and toxicity in neuronal cell culture. Because Abeta binds Cu in amyloid plaques, apocyclen-tagged targeting molecules may be a promising approach to the selective degradation of Abeta in Alzheimer disease. The principle of copper capture could generalize to other amyloidoses where copper is implicated.
