ABSTRACT
Split-virus vaccine serves as a major countermeasure against influenza virus, but its effectiveness and protective action are not complete. We previously demonstrated the effect of Benifuuki, a green tea cultivar in Japan, on enhancing the split-virus vaccine-elicited immune response. However, little is known about the detail mechanisms. Here, we show that EGCG3"Me intake significantly potentiated the vaccine-elicited hemagglutination inhibition titer increase. Flow cytometry analysis revealed the increased Toll-like receptor 5 (TLR5) expression after EGCG3"Me treatment in lamina propria dendritic cells (LPDCs) and macrophages, which play crucial roles in the humoral immune system. TLR5 expression correlated with the level of interleukin-6 (IL-6)/C-C chemokine type receptor 5, which are important mediators of the humoral immunity. Taken together, In vivo and ex vivo studies showed that EGCG3"Me potentiated the split-virus vaccine-elicited immune response accompanied with the upregulation of TLR5 in intestine and splenocyte macrophages.
Subject(s)
Catechin/analogs & derivatives , Toll-Like Receptor 5/biosynthesis , Animals , Catechin/chemistry , Catechin/pharmacology , Drug Administration Schedule , Drug Synergism , Female , Hemagglutination , Immunity, Humoral , Influenza Vaccines , Japan , Macrophages/metabolism , Methylation , Mice , Mice, Inbred BALB C , Plant Extracts/chemistry , Spleen/cytology , Tea , Up-RegulationABSTRACT
TLR signaling is critical to innate immune system regulation; however, aberrant TLR signaling is involved in several diseases, including insulin resistance, Alzheimer's disease, and tumor metastasis. Moreover, a recent study found that TLR-4 signaling pathway inhibition might be a target for the suppression of chronic inflammatory disorders. In this article, we show that the green tea polyphenol epigallocatechin-3-O-gallate (EGCG) increases the expression of Toll interacting protein, a strong inhibitor of TLR4 signaling, by suppressing the expression of E74-like ETS transcription factor 1 (Elf-1). A mechanistic study revealed that EGCG suppressed Elf-1 expression via protein phosphatase 2A/cyclic GMP (cGMP)-dependent mechanisms. We also confirmed that orally administered EGCG and a cGMP inducer upregulated Toll interacting protein expression, increased intracellular levels of cGMP in macrophages, and suppressed Elf-1 expression. These data support EGCG and a cGMP inducer as potential candidate suppressors of TLR4 signaling.
Subject(s)
Catechin/analogs & derivatives , DNA-Binding Proteins/immunology , Intracellular Signaling Peptides and Proteins/immunology , Nuclear Proteins/immunology , Second Messenger Systems/immunology , Tea/chemistry , Transcription Factors/immunology , Up-Regulation/immunology , Animals , Catechin/chemistry , Catechin/pharmacology , Cyclic GMP/genetics , Cyclic GMP/immunology , DNA-Binding Proteins/genetics , Intracellular Signaling Peptides and Proteins/genetics , Male , Mice , Mice, Inbred BALB C , Nuclear Proteins/genetics , Protein Phosphatase 2/genetics , Protein Phosphatase 2/immunology , Second Messenger Systems/genetics , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/immunology , Transcription Factors/geneticsABSTRACT
Recurrence following chemotherapy is observed in the majority of patients with pancreatic ductal adenocarcinoma (PDAC). Recent studies suggest that cancer stem cells (CSCs) may be involved in PDAC recurrence and metastasis. However, an efficient approach to targeting pancreatic CSCs remains to be established. Here we show that in cancer cells overexpressing the 67-kDa laminin receptor (67LR)-dependent cyclic GMP (cGMP) inducer, epigallocatechin-3-O-gallate (EGCG) and a phosphodiesterase 3 (PDE3) inhibitor in combination significantly suppressed the Forkhead box O3 and CD44 axis, which is indispensable for the CSC properties of PDAC. We confirmed that the EGCG and PDE3 inhibitor in combination strongly suppressed tumour formation and liver metastasis in vivo. We also found that a synthesized EGCG analog capable of inducing strong cGMP production drastically suppressed the CSC properties of PDAC and extended the survival period in vivo. In conclusion, the combination treatment of EGCG and a PDE3 inhibitor as a strong cGMP inducer could be a potential treatment candidate for the eradication of CSCs of PDAC.
Subject(s)
Carcinoma, Pancreatic Ductal/metabolism , Catechin/analogs & derivatives , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Phosphodiesterase 3 Inhibitors/pharmacology , Animals , Biomarkers, Tumor , Catechin/chemistry , Catechin/pharmacology , Cell Line, Tumor , Cyclic GMP/metabolism , Cyclic Nucleotide Phosphodiesterases, Type 3/genetics , Cyclic Nucleotide Phosphodiesterases, Type 3/metabolism , Disease Models, Animal , Drug Synergism , Fluorescent Antibody Technique , Gene Expression , Humans , Mice , Phosphodiesterase 3 Inhibitors/chemistry , Xenograft Model Antitumor AssaysABSTRACT
In 95% of patients with pancreatic ductal adenocarcinoma, recurrence is observed following chemotherapy. Findings from several studies have indicated that cancer stem cells (CSCs) are resistant to anticancer agents and may be involved in cancer recurrence and metastasis. The CD44 protein is a major CSC marker, and CD44 also plays an indispensable role in the CSC properties in several cancers, including pancreatic cancer; however, no clinical approach exists to inhibit CD44 activity. Here, we have performed knock-in/knockdown experiments, and we demonstrate that the forkhead box O3 (FOXO3)/liver kinase B1 (LKB1)/AMP-activated protein kinase/peroxisome proliferator-activated receptor-γ co-activator-1ß (PGC-1ß)/pyruvate dehydrogenase-A1 pathway is essential for CD44 expression and CSC properties. We observed that patients exhibiting high pyruvate dehydrogenase-A1 expression have a poor prognosis. Systemic PGC-1ß knock-out mice are fertile and viable and do not exhibit an overt phenotype under normal conditions. This suggests that cGMP induction and PGC-1ß inhibition represent potential strategies for treating patients with pancreatic ductal adenocarcinoma.
Subject(s)
Biomarkers, Tumor/metabolism , Carcinoma, Pancreatic Ductal/metabolism , Carrier Proteins/metabolism , Forkhead Box Protein O3/metabolism , Neoplasm Proteins/metabolism , Pancreatic Neoplasms/metabolism , Signal Transduction , Animals , Biomarkers, Tumor/genetics , Carcinoma, Pancreatic Ductal/genetics , Carcinoma, Pancreatic Ductal/pathology , Carrier Proteins/genetics , Cell Line, Tumor , Female , Forkhead Box Protein O3/genetics , Humans , Male , Mice, Knockout , Neoplasm Proteins/genetics , Neoplastic Stem Cells , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/genetics , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , RNA-Binding ProteinsABSTRACT
Toll-like receptor 4 (TLR4) plays an essential role in innate immunity through inflammatory cytokine induction. Recent studies demonstrated that the abnormal activation of TLR4 has a pivotal role in obesity-induced inflammation, which is associated with several diseases, including hyperinsulinemia, hypertriglyceridemia, and cardiovascular disease. Here we demonstrate that (-)-epigallocatechin-3-O-gallate, a natural agonist of the 67-kDa laminin receptor (67LR), suppressed TLR4 expression through E3 ubiquitin-protein ring finger protein 216 (RNF216) up-regulation. Our data indicate cyclic GMP mediates 67LR agonist-dependent RNF216 up-regulation. Moreover, we show that the highly absorbent 67LR agonist (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3â³Me) significantly attenuated TLR4 expression in the adipose tissue. EGCG3â³Me completely inhibited the high-fat/high-sucrose (HF/HS)-induced up-regulation of tumor necrosis factor α in adipose tissue and serum monocyte chemoattractant protein-1 increase. Furthermore, this agonist intake prevented HF/HS-induced hyperinsulinemia and hypertriglyceridemia. Taken together, 67LR presents an attractive target for the relief of obesity-induced inflammation.
Subject(s)
Catechin/analogs & derivatives , Gene Expression Regulation/drug effects , Macrophages, Peritoneal/drug effects , Receptors, Laminin/metabolism , Tea/chemistry , Toll-Like Receptor 4/metabolism , Ubiquitin-Protein Ligases/metabolism , Animals , Catechin/pharmacology , Cells, Cultured , Hyperinsulinism/metabolism , Hyperinsulinism/prevention & control , Hypertriglyceridemia/metabolism , Hypertriglyceridemia/prevention & control , Inflammation/etiology , Inflammation/prevention & control , Lipopolysaccharides/pharmacology , Macrophages, Peritoneal/cytology , Macrophages, Peritoneal/metabolism , Male , Mice , Mice, Inbred C57BL , NF-kappa B/genetics , NF-kappa B/metabolism , Obesity/etiology , Obesity/prevention & control , Receptors, Laminin/agonists , Receptors, Laminin/genetics , Signal Transduction/drug effects , Toll-Like Receptor 4/genetics , Transcriptional Activation , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism , Ubiquitin-Protein Ligases/genetics , Up-RegulationABSTRACT
Influenza is a widespread disease caused by infection with the influenza virus. Vaccination is considered to be the main countermeasure against influenza. A split vaccine is widely used to avoid severe adverse events, and it induces strong humoral immunity. However, the split vaccine alone cannot elicit mucosal immunity, including IgA production, and its preventative effects are limited. Here, we show that the green tea cultivar 'Benifuuki' extract enhanced the effect of a split vaccine on mucosal immunity. The frequency of IgA+ cells was increased in lung and Peyer's patch that received Benifuuki diet. Secretion of hemagglutinin-specific mucosal IgA, which is closely linked to the prevention of viral infection, was significantly increased in the bronchoalveolar lavage fluid of split vaccine-immunized BALB/c mice that were administered green tea Benifuuki extract. Our findings suggest that Benifuuki intake enhanced the effects of the split vaccine on mucosal immunity.
