Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Cancers (Basel) ; 14(20)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36291919

RESUMO

The use of cancer vaccines is a promising therapeutic strategy able to stimulate anti-tumor immunity by inducing both humoral and cellular immunity. In this study, antigen presenting cells play a key role by inducing a strong activation of the T cell-mediated adaptive immune response, essential for the anti-tumor potential of cancer vaccines. The first human candidate vaccine created from the KISIMA platform, ATP128, bears three tumor-associated antigens highly expressed in colorectal cancer tissues. At the N-terminus, the cell-penetrating peptide allows the antigen delivery inside the cell and, together with the TLR agonist-derived peptide at the C-terminus, ensures the activation of the monocyte-derived dendritic cells. Here, we show that ATP128 leads to both NF-κB and IRF3 pathway activation, with subsequent pro-inflammatory cytokines and type I Interferon release, as well as an increase in the expression of costimulatory molecules, alongside an upregulation of MHC class I molecules. This cellular immune response involves TLR2 and TLR4, for both membrane and intracellular signaling. We demonstrated an endocytic component in ATP128's activity by combining the use of a variant of ATP128 lacking the cell-penetrating peptide with endocytosis inhibitors. Importantly, this internalization step is detemined essential for the activation of the IRF3 pathway. This study validates the design of the self-adjuvanting ATP128 vaccine for cancer immunotherapy.

2.
J Med Chem ; 64(19): 14377-14425, 2021 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-34569791

RESUMO

This study describes a novel series of UDP-N-acetylglucosamine acyltransferase (LpxA) inhibitors that was identified through affinity-mediated selection from a DNA-encoded compound library. The original hit was a selective inhibitor of Pseudomonas aeruginosa LpxA with no activity against Escherichia coli LpxA. The biochemical potency of the series was optimized through an X-ray crystallography-supported medicinal chemistry program, resulting in compounds with nanomolar activity against P. aeruginosa LpxA (best half-maximal inhibitory concentration (IC50) <5 nM) and cellular activity against P. aeruginosa (best minimal inhibitory concentration (MIC) of 4 µg/mL). Lack of activity against E. coli was maintained (IC50 > 20 µM and MIC > 128 µg/mL). The mode of action of analogues was confirmed through genetic analyses. As expected, compounds were active against multidrug-resistant isolates. Further optimization of pharmacokinetics is needed before efficacy studies in mouse infection models can be attempted. To our knowledge, this is the first reported LpxA inhibitor series with selective activity against P. aeruginosa.


Assuntos
Aciltransferases/antagonistas & inibidores , Antibacterianos/farmacologia , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/química , Cristalografia por Raios X , Farmacorresistência Bacteriana/efeitos dos fármacos , Inibidores Enzimáticos/química , Escherichia coli/enzimologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade
3.
Res Microbiol ; 161(7): 515-25, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20472057

RESUMO

The gene encoding beta-galactosidase from dairy Streptococcus thermophilus strain LMD9 was cloned, sequenced and expressed in Escherichia coli. The recombinant enzyme was purified and showed high specific activity of 464 U/mg. This protein displays a homotetrameric arrangement composed of four 118 kDa monomers. Monitoring of the activity showed that this enzyme was optimally active at a wide range of temperatures (25-40 degrees C) and at pH from 6.5 to 7.5. Immobilization of the recombinant E. coli in alginate beads clearly enhanced the enzyme activity at various temperatures, including 4 and 50 degrees C, and at pH values from 4.0 to 8.5. Stability studies indicated that this biocatalyst has high stability within a broad range of temperatures and pH. This stability was improved not only by addition of 1 mM of Mn(2+) and 1.2 mM Mg(2+), but essentially through immobilization. The remarkable bioconversion rates of lactose in milk and whey at different temperatures revealed the attractive catalytic efficiency of this enzyme, thus promoting its use for lactose hydrolysis in milk and other dairy products.


Assuntos
Lactose/metabolismo , Streptococcus thermophilus/enzimologia , beta-Galactosidase/metabolismo , Animais , Sequência de Bases , Reatores Biológicos , Clonagem Molecular , Laticínios , Estabilidade Enzimática , Enzimas Imobilizadas , Escherichia coli/genética , Expressão Gênica , Genes Bacterianos , Hidrólise , Óperon Lac , Leite/metabolismo , Proteínas do Leite/metabolismo , Reação em Cadeia da Polimerase , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNA , Streptococcus thermophilus/genética , Proteínas do Soro do Leite , beta-Galactosidase/química , beta-Galactosidase/genética , beta-Galactosidase/isolamento & purificação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...