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

Toll-like receptors (TLRs) are pivotal components of the innate immune response, which is responsible for eradicating invading microorganisms through the induction of inflammatory molecules. These receptors are also involved in responding to harmful endogenous molecules and have crucial roles in the activation of the innate immune system and shaping the adaptive immune response. However, TLR signaling pathways must be tightly regulated because undue TLR stimulation may disrupt the fine balance between pro- and anti-inflammatory responses. Such disruptions may harm the host through the development of autoimmune and inflammatory diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Several studies have investigated the regulatory pathways of TLRs that are essential for modulating proinflammatory responses. These studies reported several pathways and molecules that act individually or in combination to regulate immune responses. In this review, we have summarized recent advancements in the elucidation of the negative regulation of TLR signaling. Moreover, this review covers the modulation of TLR signaling at multiple levels, including adaptor complex destabilization, phosphorylation and ubiquitin-mediated degradation of signal proteins, manipulation of other receptors, and transcriptional regulation. Lastly, synthetic inhibitors have also been briefly discussed to highlight negative regulatory approaches in the treatment of inflammatory diseases.
Animals ; Cytokines/biosynthesis ; Humans ; Ligands ; Models, Immunological ; Signal Transduction/*immunology ; Toll-Like Receptors/antagonists & inhibitors/*metabolism

OBJECTIVETo investigate the effects of tumor necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma) on the expression of pattern recognition receptors (PRRs) on the surface of mouse alveolar macrophages.

METHODSAlveolar macrophages from mouse were cultured in DMEM supplemented with 10% (V/V) endotoxin-free calf serum. After the alveolar macrophages were stimulated with TNF alpha and IFN gamma (concentration, 20 ng/ml) for 3 h, 6 h and 12 h, the expression of PRRs, including cluster of differentiation 14 (CD14), scavenger receptor (SR), toll-like receptor 4 (TLR4), TLR2 and TLR9 mRNA and proteins were examined by RT-PCR and immunohistochemistry.

RESULTSThe expressions of CD14, TLR2 and TLR9 receptors, which were related with cellular activation, were up-regulated by the stimulation of TNF alpha and IFN gamma (P < 0.05), while SR, which was related with cellular defense action, was down-regulated (P < 0.05). Although the expression of TLR4 was up-regulated, there was no statistical significance (P > 0.05).

CONCLUSIONSThe cytokines such as TNF alpha and IFN gamma could also produce feedback regulation on the expression of PRRs at the levels of genes and proteins. Such regulation on the PRRs expression would be significant for further amplification of inflammation cascade and eventually leading to uncontrolled inflammation.

Animals ; Cells, Cultured ; Interferon-gamma ; pharmacology ; Lipopolysaccharide Receptors ; biosynthesis ; genetics ; Macrophages, Alveolar ; metabolism ; Mice ; RNA, Messenger ; genetics ; Receptors, Pattern Recognition ; biosynthesis ; Toll-Like Receptor 2 ; biosynthesis ; genetics ; Toll-Like Receptor 4 ; biosynthesis ; genetics ; Toll-Like Receptor 9 ; biosynthesis ; genetics ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo investigate the protective mechanisms of Radix Salviae miltiorrhizae (RSM) on chronic alcoholic liver injury in mice.

METHODSThe chronic alcoholic liver injury mouse model was established. The morphologic change of hepatic tissue was observed with hematoxylin-eosin (HE) staining; the levels of toll-like receptor-4 (TLR-4) mRNA in hepatic tissue and hemeoxygenase-1 (HO-1) mRNA were determined using reverse transcription polymerase chain reaction (RT-PCR) technique; and the expression of TLR-4 protein was determined by immunohistochemistry method.

RESULTSRSM could alleviate the fatty degeneration and adiponecrosis of hepatic cells induced by alcohol, down-regulate the expressions of TLR-4 mRNA and HO-1 mRNA, and significantly decrease the number of TLR-4 positive cells.

CONCLUSIONRSM could prevent liver injury from alcohol by way of influencing TLR-4 signal transcription.

Animals ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Heme Oxygenase (Decyclizing) ; biosynthesis ; genetics ; Heme Oxygenase-1 ; Hepatitis, Alcoholic ; drug therapy ; pathology ; Liver ; metabolism ; Male ; Membrane Glycoproteins ; biosynthesis ; genetics ; Membrane Proteins ; Mice ; Phytotherapy ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, Cell Surface ; biosynthesis ; genetics ; Salvia miltiorrhiza ; Toll-Like Receptor 4 ; Toll-Like Receptors

BACKGROUNDTrichophyton rubrum (T. rubrum) represents the most important agent of dermatophytosis in humans. T. rubrum infection causes slight inflammation, and tends to be chronic and recurrent. It is suggested that it may result from the failure of epithelial cells to recognize T. rubrum effectively and initiate effective immune responses. The C-type lectin receptors (CLR) and toll-like receptors (TLR) are the two major pattern recognition receptors (PRRs) that recognize fungal components. Therefore, the purpose of the study was to analyze the expression of those PRRs and the cytokines in HaCaT cells stimulated with heat-inactivated T. rubrum conidia and hyphae, respectively.

METHODSHaCaT cells were unstimulated or stimulated with heat-inactivated T. rubrum conidia and hyphae (1×10(6) and 1.5×10(5) colony-forming unit (CFU) in 2 ml medium, respectively) for 6, 12 and 24 hours. The mRNA expression of PRRs involved in recognizing fungal pathogen-associated molecular patterns (PAMPs) and signaling molecules were measured by quantitative reverse transcription polymerase chain reaction (RT-PCR). Meanwhile, surface toll-like receptor (TLR) 2, TLR4 and Dectin-1 were analyzed by fluorescence-activated cell sorter (FACS) 24 hours after treatment. The cytokines were detected in cell culture supernatants of HaCaT cells in 12 and 24 hours after treatment.

RESULTSHaCaT cells constitutively expressed mRNA of membrane-bound TLR1, 2, 4 and 6, Dectin1 and DC-SIGN, but not Dectin-2 or Mincle. Heat-killed T. rubrum did not significantly upregulate gene transcriptions of the PRRs of HaCaT cells. Heat-inactivated T. rubrum conidia significantly reduced the surface expression of TLR2 and Dectin-1, and suppressed the secretions of interferon-inducible protein-10 (IP-10) and monocyte chemotactic protein-1 (MCP-1) of HaCaT cells, while heat-killed T. rubrum hyphae significantly induced the secretions of IP-10 and MCP-1.

CONCLUSIONThe cell-wall antigens of T. rubrum fail to activate transcriptional expression of PRRs and induce a lower immune response of HaCaT cells by limited cytokines secretion.

Cells, Cultured ; Cytokines ; biosynthesis ; Humans ; Keratinocytes ; immunology ; Lectins, C-Type ; genetics ; physiology ; RNA, Messenger ; analysis ; Receptors, Pattern Recognition ; genetics ; physiology ; Toll-Like Receptor 2 ; physiology ; Trichophyton ; immunology

Dendritic cells (DCs) comprise two functionally distinct subsets: plasmacytoid DCs (pDCs) and myeloid DCs (mDCs). pDCs are specialized in rapid and massive secretion of type I interferon (IFN-I) in response to nucleic acids through Toll like receptor (TLR)-7 or TLR-9. In this report, we characterized a CD56(+) DC population that express typical pDC markers including CD123 and BDCA2 but produce much less IFN-I comparing with pDCs. In addition, CD56(+) DCs cluster together with mDCs but not pDCs by genome-wide transcriptional profiling. Accordingly, CD56(+) DCs functionally resemble mDCs by producing IL-12 upon TLR4 stimulation and priming naïve T cells without prior activation. These data suggest that the CD56(+) DCs represent a novel mDC subset mixed with some pDC features. A CD4(+)CD56(+) hematological malignancy was classified as blastic plasmacytoid dendritic cell neoplasm (BPDCN) due to its expression of characteristic molecules of pDCs. However, we demonstrated that BPDCN is closer to CD56(+) DCs than pDCs by global gene-expression profiling. Thus, we propose that the CD4(+)CD56(+) neoplasm may be a tumor counterpart of CD56(+) mDCs but not pDCs.
Biomarkers ; metabolism ; CD56 Antigen ; genetics ; immunology ; Cell Lineage ; genetics ; immunology ; Dendritic Cells ; immunology ; metabolism ; pathology ; Gene Expression ; Hematologic Neoplasms ; genetics ; immunology ; pathology ; Humans ; Immunophenotyping ; Interferon Type I ; biosynthesis ; metabolism ; Interleukin-12 ; biosynthesis ; metabolism ; Interleukin-3 Receptor alpha Subunit ; genetics ; immunology ; Lectins, C-Type ; genetics ; immunology ; Membrane Glycoproteins ; genetics ; immunology ; Myeloid Cells ; immunology ; metabolism ; pathology ; Receptors, Immunologic ; genetics ; immunology ; Terminology as Topic ; Toll-Like Receptor 4 ; genetics ; immunology ; Toll-Like Receptor 7 ; genetics ; immunology ; Toll-Like Receptor 9 ; genetics ; immunology

MicroRNAs (miRNAs) have been demonstrated to play an important role in regulation of the immunoinflammatory response; however, the function of miRNAs in periodontal inflammation has not been investigated. The objective of this study was to explore the properties of miRNAs in periodontal inflammation by comparing miRNA profiles of inflamed and healthy gingival tissues. Gingival tissues were obtained from 10 periodontitis patients and 10 healthy subjects. After RNA extraction, miRNA profiles were analyzed by microarray, and expression levels of selected miRNAs were confirmed by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR). Analyses using two computational methods, Targetscan and MicroRNA.org, were combined to identify common targets of these miRNAs. Finally, the individual miRNA expression levels of three toll-like receptor (TLR)-related miRNAs from inflamed and healthy gingival tissues were evaluated by RT-PCR. Ninety-one miRNAs were found to be upregulated and thirty-four downregulated over two-fold in inflamed gingival tissue compared with those in healthy gingival tissue. Twelve selected inflammatory-related miRNAs, hsa-miR-126*, hsa-miR-20a, hsa-miR-142-3p, hsa-miR-19a, hsa-let-7f, hsa-miR-203, hsa-miR-17, hsa-miR-223, hsa-miR-146b, hsa-miR-146a, hsa-miR-155, and hsa-miR-205 showed comparable expression levels by microarray and real-time quantitative RT-PCR analyses. In addition, the putative inflammation targets of these miRNAs were predicted, and three that were tested (hsa-miRNA-146a, hsa-miRNA-146b, and hsa-miRNA-155), showed significant differences between inflamed and healthy gingiva. This remarkable difference in miRNA profiles between periodontal diseased and healthy gingiva implicates a probable close relationship between miRNAs and periodontal inflammation. The data also suggest that the regulation of TLRs in periodontal inflammation may involve miRNA pathways.
Adult ; Case-Control Studies ; Chronic Periodontitis ; genetics ; metabolism ; Computational Biology ; methods ; Female ; Gene Expression Profiling ; Gingiva ; metabolism ; Humans ; Male ; MicroRNAs ; biosynthesis ; genetics ; Middle Aged ; Oligonucleotide Array Sequence Analysis ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, RNA ; Toll-Like Receptors ; genetics

OBJECTIVETo investigate the influences of Shensu Yin to RAW 264.7 on the expression of TLR3, TLR4 and the factors of the downstream in RAW 264. 7 cells.

METHODRAW 264.7 cell line was stimulated with Lipopolysaccharide and POLY I: C, respectively, and treated with the drug serum of Shensuyin simultaneously. 24 hours later, collected the supernatant and measured the inflammatory factors TNF-alpha and IFN-beta, extracted mRNA and measured the expression of TLR3, TLR4 and other correlated indexes of the downstream, analyzed and evaluated Shensu Yin's substance basis of pharmacodynamic actions.

RESULTShensu Yin drug serum depressed the expression of TLR4, MyD88, TRAF-6, TRAM and TRIF mRNA, as a result, it decreased the amount of TNF-alpha and IFN-beta.

CONCLUSIONDepressing the expression of TLR3, MyD88, TRAM and TRIF mRNA may be the elementary basis of Shensu Yin to play heat-clearing and detoxicating effect.

Adaptor Proteins, Vesicular Transport ; genetics ; Animals ; Cell Line ; Drug Combinations ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Interferon-beta ; secretion ; Lipopolysaccharides ; pharmacology ; Macrophages ; cytology ; drug effects ; metabolism ; Male ; Mice ; Myeloid Differentiation Factor 88 ; genetics ; Plants, Medicinal ; chemistry ; Poly I-C ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Interleukin ; genetics ; Signal Transduction ; drug effects ; Toll-Like Receptor 3 ; genetics ; Toll-Like Receptor 4 ; genetics ; Tumor Necrosis Factor-alpha ; secretion

OBJECTIVETo study the effects of artesunate on CD14 and toll-like receptor 4 (TLR 4) expressions in peritoneal macrophages of mice with heat stroke endotoxemia.

METHODSKunming mice were randomly divided into the normal temperature group, the hyperthermia group, the normal saline (NS) group and the artesunate group (both i.p.60 mg/kg daily for consecutive five days). The normal temperature group was exposed to the condition of dry bulb temperature (Tdb) 25 degrees C +/- 0.5 degrees C and relative humidity (RH) 43% +/- 5% for 2 hours, while other groups were exposed to the condition of Tdb 35 degrees C +/- 0.5 degrees C and RH 65% +/- 5%. The mRNA expressions of CD14 and TLR 4 in peritoneal macrophages and concentrations of tumor necrosis factor alpha (TNF alpha) in plasma were observed in different time points (1 hour and 2 hour).

RESULTSThe mRNA expressions of CD14 and TLR 4 in the normal temperature group were 0.34% +/- 0.047% and 0.31% +/- 0.062% respectively. The expressions of two receptors at 1 hour in the hyperthermia group were significantly increased to 0.53% +/- 0.085% and 0.45% +/- 0.049% compared with the normal group and kept increased at 2 hour (P < 0.01). The mRNA expressions at 1 hour in the NS group were significantly increased but a little bit decreased at 2 hour. The mRNA expressions of CD14 and TLR 4 at 1 hour in the artesunate group were 0.26% +/- 0.051% and 0.25% +/- 0.084% respectively and a little bit decreased at 2 hour. The change of TNF-alpha in each group was almost consistent with the changes of CD14 and TLR 4.

CONCLUSIONArtesunate can reduce significantly the expressions of CD14 and TLR 4 in LPS signal transduction pathway and the concentration of TNF-alpha, which perhaps is one of the most important mechanisms that artesunate fights against endotoxemia.

Animals ; Artemisinins ; pharmacology ; Cells, Cultured ; Endotoxemia ; metabolism ; Female ; Gene Expression ; drug effects ; Heat Stroke ; metabolism ; Lipopolysaccharide Receptors ; biosynthesis ; genetics ; Macrophages, Peritoneal ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred Strains ; RNA, Messenger ; genetics ; Random Allocation ; Sesquiterpenes ; pharmacology ; Signal Transduction ; drug effects ; Toll-Like Receptor 4 ; biosynthesis ; genetics

The activation of nuclear factor of activated T cells 5 (NFAT5), a well-known osmoprotective factor, can be induced by isotonic stimuli, such as activated Toll-like receptors (TLRs). It is unclear, however, how NFAT5 discriminates between isotonic and hypertonic stimuli. In this study we identified a novel context-dependent suppression of NFAT5 target gene expression in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS) or a high salt (NaCl) concentration. Although LPS and NaCl both used NFAT5 as a core transcription factor, these stimuli mutually inhibited distinct sets of NFAT5 targets within the cells. Although reactive oxygen species (ROS) are essential for this inhibition, the source of ROS differed depending on the context: mitochondria for high salt and xanthine oxidase for TLRs. Specifically, the high salt-induced suppression of interleukin-6 (IL-6) production was mediated through the ROS-induced inhibition of NFAT5 binding to the IL-6 promoter. The context-dependent inhibition of NFAT5 target gene expression was also confirmed in mouse spleen and kidney tissues that were cotreated with LPS and high salt. Taken together, our data suggest that ROS function as molecular sensors to discriminate between TLR ligation and osmotic stimuli in RAW 264.7 macrophages, directing NFAT5 activity toward proinflammatory or hypertonic responses in a context-dependent manner.
Animals ; *Gene Expression Regulation/drug effects ; Interleukin-6/biosynthesis/genetics ; Lipopolysaccharides/pharmacology ; Macrophages/drug effects/metabolism ; Male ; Mannitol/pharmacology ; Mice ; Mice, Inbred BALB C ; NF-kappa B/metabolism ; Promoter Regions, Genetic/genetics ; Protein Binding/drug effects/genetics ; Reactive Oxygen Species/*metabolism ; Rotenone/pharmacology ; Sodium Chloride/pharmacology ; Toll-Like Receptors ; Transcription Factors/genetics/*metabolism