Toll-like receptor 9 binds to DNA from bacteria or viruses and activates a signaling pathway that leads to the induction of proinflammatory cytokines and type I interferon. Adaptor complex AP-3 was required for TLR9 trafficking and the production of type I interferon but not for proinflammatory cytokines. This suggests that TLR9 signaling is regulated by the subcellular localization of the receptor.
Bacteria ; Cytokines ; DNA ; Interferon Type I ; Toll-Like Receptor 9 ; Toll-Like Receptors

Several evidences suggested that Toll-like receptor 9 (TLR9) plays an important role in atherosclerosis and neuroprotection but the association between the TLR9 and risk for stroke or outcomes after stroke has not been investigated. The aim of the present study was to investigate the association between TLR9 polymorphisms and the risk for ischemic stroke using a case-control study design. We also explored the correlation between the polymorphisms and outcomes after stroke. We enrolled consecutive Korean stroke patients and controls without history of stroke. Four polymorphisms, namely c.-1486T>C, c.-1237C>T, c.1174A>G, and c.2848G>A were examined using polymerase chain reaction followed by direct sequencing. Initially we examined 193 stroke patients and the same number of healthy adults who had no history of stroke as controls. Due to deviation from Hardy-Weinberg equilibrium of initial controls, we performed genetic analysis of two polymorphisms (c.1174A>G and c.2848G>A) for additional 165 controls. The genotype frequency of four polymorphisms did not differ significantly between stroke patients and controls in unadjusted analysis. The variant allele (C) in c.-1486 locus was associated with significantly increased chance of favorable functional outcome at three month after stroke (OR 2.32, 95% CI 1.02~5.26, p = 0.043).
Adult ; Alleles ; Atherosclerosis ; Case-Control Studies ; Genotype ; Humans ; Polymerase Chain Reaction ; Stroke* ; Toll-Like Receptor 9* ; Toll-Like Receptors*

BACKGROUNDThe Toll-like receptors (TLRs) represent a group of single-pass transmembrane receptors expressed on sentinel cells that are central to innate immune responses.The aim of this study was to investigate the presence of soluble TLRs in pleural effusions, and the diagnostic values of TLRs for pleural effusion with various etiologies.

METHODSPleural effusion and serum samples were collected from 102 patients (36 with malignant pleural effusion, 36 with tuberculous pleural effusion, 18 with bacterial pleural effusion, and 12 with transudative pleural effusion). The concentrations of TLR1 to TLR10 were determined in effusion and serum samples by enzyme linked immunosorbent assay. Four classical parameters (protein, lactate dehydrogenase, glucose and C-reactive protein (CRP)) in the pleural fluid were also assessed. Receiver-operating characteristic curves were used to assess the sensitivity and specificity of pleural fluid TLRs and biochemical parameters for differentiating bacterial pleural effusion.

RESULTSThe concentrations of TLR1, TLR3, TLR4, TLR7 and TLR9 in bacterial pleural effusion were significantly higher than those in malignant, tuberculous, and transudative groups, respectively. Analysis of receiver operating characteristic curves revealed that the area under the curves of TLR1, TLR3, TLR4, TLR7 and TLR9 were 0.831, 0.843, 0.842, 0.883 and 0.786, respectively, suggesting that these TLRs play a role in the diagnosis of bacterial pleural effusion. Also, the diagnostic value of TLRs for bacterial pleural effusions was much better than that of biochemical parameters (protein, lactate dehydrogenase, glucose and CRP).

CONCLUSIONSThe concentrations of TLR1, TLR3, TLR4, TLR7 and TLR9 appeared to be increased in bacterial pleural effusion compared to non-bacterial pleural effusions. Determination of these pleural TLRs may improve the ability of clinicians to differentiate pleural effusion patients of bacterial origin from those with other etiologies.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Bacterial Infections ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Middle Aged ; Pleural Effusion ; metabolism ; microbiology ; Prospective Studies ; Toll-Like Receptor 1 ; metabolism ; Toll-Like Receptor 3 ; metabolism ; Toll-Like Receptor 4 ; metabolism ; Toll-Like Receptor 7 ; metabolism ; Toll-Like Receptor 9 ; metabolism ; Toll-Like Receptors ; metabolism ; Young Adult

Desensitization, Immunologic ; methods ; Oligodeoxyribonucleotides ; therapeutic use ; Toll-Like Receptor 9 ; therapeutic use

OBJECTIVEThis study examined the expression of Toll-like receptors (TLR) in peripheral blood mononuclear cells (PBMC) and serum levels of IL-6, IL-10 and TNF-alpha in children with recurrent herpes simplex, in order to investigate the role of TLR2 and TLR9 in recurrent herpes simplex.

METHODSThe expression of TLR2 and TLR9 in PBMC was examined by flow cytometer, and serum levels of IL-6, IL-10 and TNF-alpha were detected using ELISA in 22 children with recurrent herpes simplex and in 13 age-matched healthy volunteers.

RESULTSThe expression of both TLR2 and TLR9 obviously increased in children with recurrent herpes simplex compared with that in healthy controls (p<0.01). Serum levels of IL-6 and IL-10 increased, while serum TNF-alpha levels decreased significantly in children with recurrent herpes simplex compared with those in healthy controls (p<0.01). There were positive correlations between TLR2 and TLR9 expression and serum IL-6 and IL-10 levels in children with recurrent herpes simplex (p<0.01).

CONCLUSIONSTLR2 and TLR9 in PBMC may participate in the recognition of herpes simplex virus and activate the signal pathway of TLR in children with recurrent herpes simplex. The production and release of IL-6 and IL-10 might be mediated by TLR2 and TLR9.

Adolescent ; Child ; Child, Preschool ; Cytokines ; blood ; Female ; Herpes Simplex ; immunology ; Humans ; Leukocytes, Mononuclear ; chemistry ; Male ; Recurrence ; Toll-Like Receptor 2 ; blood ; Toll-Like Receptor 9 ; blood

Plasmacytoid dendritic cells (pDCs), also known as type I interferon (IFN)-producing cells, are specialized immune cells characterized by their extraordinary capabilities of mounting rapid and massive type I IFN response to nucleic acids derived from virus, bacteria or dead cells. PDCs selectively express endosomal Toll-like receptor (TLR) 7 and TLR9, which sense viral RNA and DNA respectively. Following type I IFN and cytokine responses, pDCs differentiate into antigen presenting cells and acquire the ability to regulate T cell-mediated adaptive immunity. The functions of pDCs have been implicated not only in antiviral innate immunity but also in immune tolerance, inflammation and tumor microenvironments. In this review, we will focus on TLR7/9 signaling and their regulation by pDC-specific receptors.
Animals ; Dendritic Cells ; cytology ; metabolism ; Humans ; Protein Transport ; Proteolysis ; Signal Transduction ; Toll-Like Receptor 7 ; chemistry ; metabolism ; Toll-Like Receptor 9 ; chemistry ; metabolism

Recent studies indicate that several Toll-like receptors (TLRs) are implicated in recognizing viral structures and instigating immune responses against viral infections. The aim of this study is to examine the expression of TLRs and proinflammatory cytokines in viral skin diseases such as verruca vulgaris (VV) and molluscum contagiosum (MC). Reverse transcription-polymerase chain reaction and immunostaining of skin samples were performed to determine the expression of specific antiviral and proinflammatory cytokines as well as 5 TLRs (TLR2, 3, 4, 7, and 9). In normal human skin, TLR2, 4, and 7 mRNA was constitutively expressed, whereas little TLR3 and 9 mRNA was detected. Compared to normal skin (NS), TLR3 and 9 mRNA was clearly expressed in VV and MC specimens. Likewise, immunohistochemistry indicated that keratinocytes in NS constitutively expressed TLR2, 4, and 7; however, TLR3 was rarely detected and TLR9 was only weakly expressed, whereas 5 TLRs were all strongly expressed on the epidermal keratinocytes of VV and MC lesions. In addition, the mRNA expression of IFN-beta and TNF-alpha was upregulated in the VV and MC samples. Immunohistochemistry indicated that IFN-beta and TNF-alpha were predominately localized in the granular layer in the VV lesions and adjacent to the MC bodies. Our results indicated that VV and MC skin lesions expressed TLR3 and 9 in addition to IFN-beta and TNF-alpha. These viral-induced proinflammatory cytokines may play a pivotal role in cutaneous innate immune responses.
Cytokines/metabolism ; *Gene Expression Regulation ; Humans ; Immunohistochemistry/methods ; Inflammation ; Interferon-beta/biosynthesis ; Keratinocytes/cytology ; Models, Biological ; Molluscum Contagiosum/*metabolism ; Toll-Like Receptor 3/biosynthesis ; Toll-Like Receptor 9/biosynthesis ; Toll-Like Receptors/*biosynthesis ; Tumor Necrosis Factor-alpha/biosynthesis ; Warts/*metabolism

PURPOSE: To analyze the correlation of polymorphisms of toll-like receptor 7 (TLR7) (rs179009) and toll-like receptor 9 (TLR9) (rs187084) in hepatitis C virus (HCV) infections in the Han population. MATERIALS AND METHODS: The genotypes of TLR7IVS2-151 in HCV infection were detected by Sanger sequencing using polymerase chain reaction-restriction fragment length polymorphism to determine the TLR9 T-1486C single nucleotide polymorphisms (SNP) for all enrolled patients. RESULTS: We found no significant difference between males with spontaneous clearance of HCV versus those chronically infected [chi2=2.71, p=0.10, odd ratios (OR)=0.58, 95% confidence interval (CI) 0.31-1.11]. However, significant differences were found for the distribution of TLR7 (rs179009) in females (chi2=9.46, p=0.01). In females, a significant difference was also found between chronic hepatitis C and those with spontaneous clearance of HCV in terms of TLR7 IVS2-151G/A allele frequencies (chi2=9.50, p=0.00, OR=0.46, 95% CI 0.28-0.75). In HCV-infected patients, no significant association was found between the frequency of TLR9 genotypes and alleles. CONCLUSION: The site of TLR7 IVS2-151 (rs179009) G/A may be a factor for susceptibility of chronic HCV in the female Han population. TLR9T-1486C (rs18084) SNP may not play a major role in HCV infection. However, individual risk profiles for HCV infection did vary by sex and this relationship should be further investigated.
Alleles ; China* ; Confidence Intervals ; Female ; Gene Frequency ; Genotype ; Hepacivirus* ; Hepatitis C* ; Hepatitis C, Chronic ; Hepatitis* ; Humans ; Male ; Methods ; Polymorphism, Single Nucleotide* ; Toll-Like Receptor 7* ; Toll-Like Receptor 9* ; Toll-Like Receptors*

PURPOSE: The aim of this study is to explore the effect of the Toll-like receptor 9 (TLR9) expressed in plasmacytoid dendritic cells (pDCs) that respond to antigen to Th2 immune deviation in allergic patients. METHODS: Subjects consisted of 19 allergic patients and 17 healthy volunteers. Skin prick tests and nasal provocation tests were performed for the two groups. Peripheral blood mononuclear cells (PBMCs) were collected from subjects and analyzed for the Lineage Cocktail (CD3, CD14, CD16, CD19, CD20, CD56) (-), HLA-DR (+), and CD123 (+) using flow cytometry. In addition, we analyzed TLR9 mRNA by reverse transcriptase-polymerase chain reaction. The level of interferon-alpha (IFN-alpha) of the PBMCs following stimulation with the TLR9 ligand CpG-ODN 2216 was also evaluated. RESULTS: Analyses of CD123 (+) revealed a nearly similar distribution for the classical pDC markers in the allergic group (0.1%+/-0.04%) and in the controls (0.25%+/-0.23%). The mRNA levels of TLR9 on PBMCs were not different between the allergic group and the controls (1.29+/-0.41 vs. 1.25+/-0.23, respectively). Additionally, the level of IFN-alpha in PBMCs exposed to stimuli of the TLR9 ligand CpG-ODN 2216 was not significantly different between the two groups (911+/-829 vs. 1,095+/-888 pg/mL, respectively). CONCLUSIONS: We found no evidence that TLR9-dependent immune responses in human pDCs are associated with allergic status.
Dendritic Cells ; Flow Cytometry ; HLA-DR Antigens ; Humans ; Hypersensitivity ; Interferon-alpha ; Nasal Provocation Tests ; Oligodeoxyribonucleotides ; RNA, Messenger ; Skin ; Toll-Like Receptor 9 ; Toll-Like Receptors

PURPOSE: The aim of this study is to explore the effect of the Toll-like receptor 9 (TLR9) expressed in plasmacytoid dendritic cells (pDCs) that respond to antigen to Th2 immune deviation in allergic patients. METHODS: Subjects consisted of 19 allergic patients and 17 healthy volunteers. Skin prick tests and nasal provocation tests were performed for the two groups. Peripheral blood mononuclear cells (PBMCs) were collected from subjects and analyzed for the Lineage Cocktail (CD3, CD14, CD16, CD19, CD20, CD56) (-), HLA-DR (+), and CD123 (+) using flow cytometry. In addition, we analyzed TLR9 mRNA by reverse transcriptase-polymerase chain reaction. The level of interferon-alpha (IFN-alpha) of the PBMCs following stimulation with the TLR9 ligand CpG-ODN 2216 was also evaluated. RESULTS: Analyses of CD123 (+) revealed a nearly similar distribution for the classical pDC markers in the allergic group (0.1%+/-0.04%) and in the controls (0.25%+/-0.23%). The mRNA levels of TLR9 on PBMCs were not different between the allergic group and the controls (1.29+/-0.41 vs. 1.25+/-0.23, respectively). Additionally, the level of IFN-alpha in PBMCs exposed to stimuli of the TLR9 ligand CpG-ODN 2216 was not significantly different between the two groups (911+/-829 vs. 1,095+/-888 pg/mL, respectively). CONCLUSIONS: We found no evidence that TLR9-dependent immune responses in human pDCs are associated with allergic status.
Dendritic Cells ; Flow Cytometry ; HLA-DR Antigens ; Humans ; Hypersensitivity ; Interferon-alpha ; Nasal Provocation Tests ; Oligodeoxyribonucleotides ; RNA, Messenger ; Skin ; Toll-Like Receptor 9 ; Toll-Like Receptors