Airway Epithelial Expression of TLR5 Is Downregulated in Healthy Smokers and Smokers with Chronic Obstructive Pulmonary Disease

The TLRs are important components of the respiratory epithelium host innate defense, enabling the airway surface to recognize and respond to a variety of insults in inhaled air. On the basis of the knowledge that smokers are more susceptible to pulmonary infection and that the airway epithelium of smokers with chronic obstructive pulmonary disease (COPD) is characterized by bacterial colonization and acute exacerbation of airway infections, we assessed whether smoking alters expression of TLRs in human small airway epithelium, the primary site of smoking-induced disease. Microarrays were used to survey the TLR family gene expression in small airway (10th to 12th order) epithelium from healthy nonsmokers (n = 60), healthy smokers (n = 73), and smokers with COPD (n = 36). Using the criteria of detection call of present (P call) ≥50%, 6 of 10 TLRs (TLRs 1-5 and 8) were expressed. Compared with nonsmokers, the most striking change was for TLR5, which was downregulated in healthy smokers (1.4-fold, p < 10(-10)) and smokers with COPD (1.6-fold, p < 10(-11)). TaqMan RT-PCR confirmed these observations. Bronchial biopsy immunofluorescence studies showed that TLR5 was expressed mainly on the apical side of the epithelium and was decreased in healthy smokers and smokers with COPD. In vitro, the level of TLR5 downstream genes, IL-6 and IL-8, was highly induced by flagellin in TLR5 high-expressing cells compared with TLR5 low-expressing cells. In the context that TLR5 functions to recognize pathogens and activate innate immune responses, the smoking-induced downregulation of TLR5 may contribute to smoking-related susceptibility to airway infection, at least for flagellated bacteria.     

Antagonist-mediated down-regulation of toll-like receptors increases the prevalence of human papillomavirus infection in systemic lupus erythematosus

IntroductionPrevalence of an abnormal Papanicolaou smear was significantly increased in lupus patients in cross-sectional studies, associated with a higher prevalence of high-risk human papillomavirus (HPV) infection. The nucleic acid-specific Toll-like receptors (TLRs) locate at the endolysosomal compartments and trigger the induction of cytokines for the innate immune response. This study evaluated whether abnormal host innate immune response in lupus patients may enhance HPV persistence.MethodsProtein levels of TLRs 3, 7, 8 and 9 in cervical epithelial cells of lupus patients and controls with or without HPV infection were assessed using flow cytometry. Characteristics associated with the differential expression of TLRs in systemic lupus erythematosus (SLE) were elucidated. The effect and interferon-stimulated genes (ISGs) (ISG15 and Mx-1) gene expressions were then measured in oncogenic HeLa (HPV18), CaSki (HPV) and C33A (HPV negative) cell lines using flow cytometry and quantitative real-time PCR. Ex vivo productions of cytokines and interferon-gamma (IFN-γ) upon TLR ligands stimulations were subsequently measured using cytometric bead array and ELISA.ResultsFor subjects with HPV infection, levels of TLR3 and TLR7 were significantly lower in lupus patients compared with controls. Significantly decreased TLRs 7, 8 and 9 levels were observed in HPV-negative SLE compared to healthy controls. For SLE with and without HPV infection, TLR7 and 9 levels were significantly lower in infected SLE than those in HPV-negative patients. Independent explanatory variables associated with down-regulation of TLR7 level included HPV infection and a higher cumulative dose of prednisolone; while a higher cumulative dose of hydroxychloroquine and HPV infection were associated with down-regulation of TLR9 level. In cervical cell lines, TLRs 3, 7, 8, 9 protein levels and antiviral ISG15 and Mx-1 gene expressions were inhibited in two oncogenic HPV types. Functional data showed that the induction of pro-inflammatory cytokines by TLR ligands (R837, ssRNA and ODN2395) was greatly impaired in CaSki and HeLa than C33A cells.ConclusionsIn conclusion, prednisolone and TLR antagonist (hydroxychloroquine) may down-regulate protein levels of TLR7 and TLR9 in lupus patients, thereby decreasing the innate immune response against HPV infection. Upon infection, HPV further down-regulate TLR7 and 9 levels for viral persistence. Furthermore, reduction of nucleic acid-sensing TLRs 7, 8 and 9 in carcinogenic HPVs ensures that the expression of inducible pro-inflammatory cytokines is minimized to prevent the expression of antiviral ISGs (ISG15 and Mx-1) on a biologically relevant antiviral response.     

Bias in effect size of systemic lupus erythematosus susceptibility loci across Europe: a case-control study

Introduction

Prevalence of an abnormal Papanicolaou smear was significantly increased in lupus patients in cross-sectional studies, associated with a higher prevalence of high-risk human papillomavirus (HPV) infection. The nucleic acid-specific Toll-like receptors (TLRs) locate at the endolysosomal compartments and trigger the induction of cytokines for the innate immune response. This study evaluated whether abnormal host innate immune response in lupus patients may enhance HPV persistence.

Methods

Protein levels of TLRs 3, 7, 8 and 9 in cervical epithelial cells of lupus patients and controls with or without HPV infection were assessed using flow cytometry. Characteristics associated with the differential expression of TLRs in systemic lupus erythematosus (SLE) were elucidated. The effect and interferon-stimulated genes (ISGs) (ISG15 and Mx-1) gene expressions were then measured in oncogenic HeLa (HPV18), CaSki (HPV) and C33A (HPV negative) cell lines using flow cytometry and quantitative real-time PCR. Ex vivo productions of cytokines and interferon-gamma (IFN-??) upon TLR ligands stimulations were subsequently measured using cytometric bead array and ELISA.

Results

For subjects with HPV infection, levels of TLR3 and TLR7 were significantly lower in lupus patients compared with controls. Significantly decreased TLRs 7, 8 and 9 levels were observed in HPV-negative SLE compared to healthy controls. For SLE with and without HPV infection, TLR7 and 9 levels were significantly lower in infected SLE than those in HPV-negative patients. Independent explanatory variables associated with down-regulation of TLR7 level included HPV infection and a higher cumulative dose of prednisolone; while a higher cumulative dose of hydroxychloroquine and HPV infection were associated with down-regulation of TLR9 level. In cervical cell lines, TLRs 3, 7, 8, 9 protein levels and antiviral ISG15 and Mx-1 gene expressions were inhibited in two oncogenic HPV types. Functional data showed that the induction of pro-inflammatory cytokines by TLR ligands (R837, ssRNA and ODN2395) was greatly impaired in CaSki and HeLa than C33A cells.

Conclusions

In conclusion, prednisolone and TLR antagonist (hydroxychloroquine) may down-regulate protein levels of TLR7 and TLR9 in lupus patients, thereby decreasing the innate immune response against HPV infection. Upon infection, HPV further down-regulate TLR7 and 9 levels for viral persistence. Furthermore, reduction of nucleic acid-sensing TLRs 7, 8 and 9 in carcinogenic HPVs ensures that the expression of inducible pro-inflammatory cytokines is minimized to prevent the expression of antiviral ISGs (ISG15 and Mx-1) on a biologically relevant antiviral response.     

Legionella pneumophila induces human beta Defensin-3 in pulmonary cells

Background

Legionella pneumophila is an important causative agent of severe pneumonia in humans. Human alveolar epithelium and macrophages are effective barriers for inhaled microorganisms and actively participate in the initiation of innate host defense. The beta defensin-3 (hBD-3), an antimicrobial peptide is an important component of the innate immune response of the human lung. Therefore we hypothesize that hBD-3 might be important for immune defense towards L. pneumophila.

Methods

We investigated the effects of L. pneumophila and different TLR agonists on pulmonary cells in regard to hBD-3 expression by ELISA. Furthermore, siRNA-mediated inhibition of TLRs as well as chemical inhibition of potential downstream signaling molecules was used for functional analysis.

Results

L. pneumophila induced release of hBD-3 in pulmonary epithelium and alveolar macrophages. A similar response was observed when epithelial cells were treated with different TLR agonists. Inhibition of TLR2, TLR5, and TLR9 expression led to a decreased hBD-3 expression. Furthermore expression of hBD-3 was mediated through a JNK dependent activation of AP-1 (c-Jun) but appeared to be independent of NF-κB. Additionally, we demonstrate that hBD-3 elicited a strong antimicrobial effect on L. pneumophila replication.

Conclusions

Taken together, human pulmonary cells produce hBD-3 upon L. pneumophila infection via a TLR-JNK-AP-1-dependent pathway which may contribute to an efficient innate immune defense.     

Hepatitis C virus induces toll-like receptor 4 expression, leading to enhanced production of beta interferon and interleukin-6

Hepatitis C virus (HCV) induces inflammatory signals, leading to hepatitis, hepatocellular carcinomas, and lymphomas. The mechanism of HCV involvement in the host's innate immune responses has not been well characterized. In this study, we analyzed expression and regulation of the entire panel of toll-like receptors (TLRs) in human B cells following HCV infection in vitro. Among all of the TLRs (TLRs 1 to 10) examined, only TLR4 showed an altered expression (a three- to sevenfold up-regulation) after HCV infection. Peripheral blood mononuclear cells from HCV-infected individuals also showed a higher expression level of TLR4 compared with those of healthy individuals. HCV infection significantly increased beta interferon (IFN-beta) and interleukin-6 (IL-6) secretion from B cells, particularly after lipopolysaccharide stimulation. The increased IFN-beta and IL-6 production was mediated by TLR4 induction, since the introduction of the small interfering RNA against TLR4 specifically inhibited the HCV-induced cytokine production. Among all of the viral proteins, only NS5A caused TLR4 induction in hepatocytes and B cells. NS5A specifically activated the promoter of the TLR4 gene in both hepatocytes and B cells. In conclusion, HCV infection directly induces TLR4 expression and thereby activates B cells, which may contribute to the host's innate immune responses.     

Expression of toll-like receptor 4 is down-regulated during progression of cervical neoplasia

Chronic infection and inflammation are among the most important factors contributing to cancer development and growth. Toll-like receptors (TLRs) are important families of pattern recognition receptors, which recognize conserved components of microbes and trigger the immune response against invading microorganisms. TLR4 is the signaling receptor for lipopolysaccharide (LPS), the endotoxic component of Gram-negative bacteria. Recent studies demonstrate that TLRs are expressed in some tumor cells, and that the expression of TLRs in these cells is associated with tumorigenesis. Cervical intraepithelial neoplasia (CIN) is a key stage in the development of cervical cancer and human papillomavirus (HPV) infection is an essential factor in cervical carcinogenesis. As the cervix is in constant contact with bacteria, especially Gram-negative bacteria, we hypothesize that TLR4-mediated bacterial stimulation may be involved in the tumorigenesis of cervical cancer. In the present study, the expression and distribution of TLR4 in CIN and cervical squamous carcinoma were investigated by immunohistochemistry. To our surprise, we observed a decrease in the expression of TLR4 during the progression of cervical neoplasia and this down-regulation of TLR4 appeared to be associated with the expression of \textP ^{1 6\textINK4A} , {\text{P}}^{{ 1 6^{\text{INK4A}} }} , which is a crucial marker of HPV integration into host cells. These data offer further insight regarding the association of HPV infection and TLR signaling during the carcinogenesis of cervical cancer.     

Expression of integrins and Toll-like receptors in cervical cancer: effect of infectious agents

We hypothesized that development of cervical cancer is associated with alterations in the expression of innate immune receptors, i.e. integrins and TLRs, and that these alterations can be induced by infectious agents. We have studied the expression of these proteins in cervical biopsy tissues and cervical cancer-derived cell lines HeLa, CaSki, SiHa, C-33?A, and ME180. Immunohistochemistry analysis demonstrated an increase in integrin αv, β3, β4, and β6 expression in the epithelium during the development of cervical cancer. A clear trend towards higher expression of integrin β6 in cell lines harbouring human papillomavirus (HPV) genetic material, compared to HPV-negative C-33?A, was observed. To investigate whether bacterial infection can alter the expression of TLRs and integrins, we infected HeLa cells by two pathogens, Escherichia coli and Pseudomonas aeruginosa, using a common bacterium of the female genital tract, Lactobacillus reuteri, as a control. Infection with E. coli or P. aeruginosa, but not with L. reuteri, significantly altered the expression of TLR and integrins, particularly of TLR4 and integrin β6. Considering that both integrin β6 and TLR4 play important roles in tumorigenesis, our data suggest that bacterial infection may trigger cancer development in HPV-infected cervical epithelium.     

Toll-like receptor 2-mediated expression of beta-defensin-2 in human corneal epithelial cells

We previously showed that human corneal epithelial cells (HCECs) express Toll-like receptors (TLRs), which recognize gram-positive bacteria and respond to Staphylococcus aureus infection by the expression and secretion of proinflammatory cytokines and beta-defensin-2 (hBD2). In this study, we further elucidated the underlying mechanisms regulating hBD-2 expression and its role in innate defense in HCECs in response to S. aureus challenge. Exposure of HUCL cells, a telomerase-immortalized HCEC line, to S. aureus, its exoproducts (1:10 dilution), or synthetic lipopeptide Pam3Cys (10 microg/ml) resulted in the up-regulation of hBD-2, but not hBD1 and hBD3. Similar to HUCL cells, primary HCECs responded to S. aureus-exoproducts and Pam3Cys challenge by expressing hBD2 mRNA and secreting hBD2 into the culture media. Furthermore, these stimuli induced the expression of TLR2 at both mRNA and protein levels. Consistently with its role as a major pattern-recognizing receptor, TLR2 was located at the cell surface by cell surface biotinylation. The treatment of HUCL cells with TLR2 neutralizing antibody resulted in a significant decrease in Pam3Cys-induced hBD2 production as well as IL-6, IL-8, and TNF-alpha secretion. The Pam3Cys-induced hBD2 expression was completely blocked by NF-kappaB inhibitors and partially inhibited by p38 MAP kinase and the JNK inhibitors. Conditioned media derived from HCECs challenged with S. aureus-exoproducts or Pam3Cys exhibited antibacterial activity against S. aureus, Pseudomonas aeruginosa and Escherichia coli. These findings suggest that S. aureus induces hBD2 production through TLR2-mediated pathways in HCECs and that pathogen-challenged, TLR-activated HCECs possess antimicrobial activity. Thus, the epithelium might play a role in innate defense against bacterial infection by directly killing bacteria in the cornea.     

Epigenetic modification of TLRs in leukocytes is associated with increased susceptibility to Salmonella enteritidis in chickens

Toll-like receptors (TLRs) signaling pathways are the first lines in defense against Salmonella enteritidis (S. enteritidis) infection but the molecular mechanism underlying susceptibility to S. enteritidis infection in chicken remains unclear. SPF chickens injected with S. enteritidis were partitioned into two groups, one consisted of those from Salmonella-susceptible chickens (died within 5 d after injection, n = 6), the other consisted of six Salmonella-resistant chickens that survived for 15 d after injection. The present study shows that the bacterial load in susceptible chickens was significantly higher than that in resistant chickens and TLR4, TLR2-1 and TLR21 expression was strongly diminished in the leukocytes of susceptible chickens compared with those of resistant chickens. The induction of expression of pro-inflammatory cytokine genes, IL-6 and IFN-β, was greatly enhanced in the resistant but not in susceptible chickens. Contrasting with the reduced expression of TLR genes, those of the zinc finger protein 493 (ZNF493) gene and Toll-interacting protein (TOLLIP) gene were enhanced in the susceptible chickens. Finally, the expression of TLR4 in peripheral blood mononuclear cells (PBMCs) infected in vitro with S. enteritidis increased significantly as a result of treatment with 5-Aza-2-deoxycytidine (5-Aza-dc) while either 5-Aza-dc or trichostatin A was effective in up-regulating the expression of TLR21 and TLR2-1. DNA methylation, in the predicted promoter region of TLR4 and TLR21 genes, and an exonic CpG island of the TLR2-1 gene was significantly higher in the susceptible chickens than in resistant chickens. Taken together, the results demonstrate that ZNF493-related epigenetic modification in leukocytes probably accounts for increased susceptibility to S. enteritidis in chickens by diminishing the expression and response of TLR4, TLR21 and TLR2-1.     

Antiviral role of toll-like receptors and cytokines against the new 2009 H1N1 virus infection

People are generally susceptible to the 2009 new mutate of H1N1 influenza due to lack of appropriate immunity. Influenza H1N1 2009 infection triggers a massive inflammatory response that contributes to fever, lung impairment or other tissue damage, eventually leading to death. Infection with pathogenic influenza virus H1N1 induces severe pulmonary immune pathology. To date, more than 10,000 cases worldwide have died of the disease. It still has strong infectious ability although the mortality of influenza isn’t currently high. Therefore, to explore the pathogenesis of H1N1 influenza can help with the disease prevention, diagnosis and provide a theoretical basis and the new ideas of treatment. Laboratory confirmed cases of pandemic influenza H1N1 2009 were enrolled to collect general information on pre-clinical, clinical and laboratory data for analysis. Blood samples were obtained from patients with H1N1, healthy volunteers and patients with bacterial pneumonia. Serum were separated and collected. RT–PCR and ELISA methods were applied to detect the different expression of TLRs and cytokines. The young, pregnant and postpartum women and infant are highly susceptible to influenza H1N1 2009 infection; degree of susceptibility is not associated with BMI. Biochemical changes can be seen in the patients with influenza H1N1 2009 infection: ALT, AST, CK, LDH increased in varying degrees. TLR2, TLR3, TLR9 expression increased in the patients with influenza H1N1 2009 infection; no obvious changes of TLR4, TLR7, TLR8 can be detected. In pregnant and postpartum women group, only TLR9 expression increased. The expression of IL-2, IL-6, IFN-γ, TNF-α in the patients with influenza H1N1 2009 infection was significantly increased; while IL-10 expression decreased and IL-4 expression did not change. H1N1 influenza-infected pregnant and postpartum women group, only IL-2 and TNF-α expression expression increased, other cytokines decreased or didn’t change. TLR2, TLR3, TLR9 are the major members of TLR family in the recognition of the novel H1N1 virus to start the innate immune response and adaptive immune responses. TLR9 may be the key receptor among pattern recognized receptors to recognize and bind to H1N1 virus. Cellular immune responses induced by Th1 may participate in modulating the influenza H1N1 2009.     

The activation of TLR7 regulates the expression of VEGF,TIMP1, MMP2, IL-6, and IL-15 in Hela cells

Toll-like receptors (TLRs) play important roles in activation of immunoreaction and tumor development. Toll-like receptor 7 (TLR7), one of the TLRs binding with single-stranded RNA, activates intracellular pathways and stimulates the release of proinflammatory cytokines, chemokines. In this study, we investigated the impact of the TLR7-signaling pathway on the expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase 2 (MMP2), tissue inhibitor of metalloproteinase 1 (TIMP1), interleukin 6 (IL-6), and interleukin 15 (IL-15), which have been testified to refer to the immunomodulating and tumor progression. We confirmed that the TLR7 was expressed by Hela cells, despite the abundance was weak. Gardiquimod, one of the TLR7 ligands, can promote these five genes expression in varying degrees. After stimulating with gardiquimod, the expression of the IL-15V1, 3 increased about 4.5 times on RNA level, the other expression was only up-regulated about 2 times. We also discovered that gardiquimod could activate the MAPK/ERK- and PI3K/AKT-signaling pathways, and the specific inhibitors studies indicate that, the effect of gardiquimod on these genes expression is mainly or partially dependent on the activation of these two signaling pathways. To sum up, the activation of TLR7 signaling pathway may modulate some genes expression in Hela cells and may contribute to the pathogenesis of the cervical cancer.     

Rhinovirus increases human beta-defensin-2 and -3 mRNA expression in cultured bronchial epithelial cells

Human beta-defensins (hBDs) are antimicrobial peptides that play important roles in host defense against infection, inflammation and immunity. Previous studies showed that micro-organisms and proinflammatory mediators regulate the expression of these peptides in airway epithelial cells. The aim of the present study was to investigate the modulation of expression of hBDs in cultured primary bronchial epithelial cells (PBEC) by rhinovirus-16 (RV16), a respiratory virus responsible for the common cold and associated with asthma exacerbations. RV16 was found to induce expression of hBD-2 and -3 mRNA in PBEC, but did not affect hBD-1 mRNA. Viral replication appeared essential for rhinovirus-induced beta-defensin mRNA expression, since UV-inactivated rhinovirus did not increase expression of hBD-2 and hBD-3 mRNA. Exposure to synthetic double-stranded RNA (dsRNA) molecule polyinosinic:polycytidylic acid had a similar effect as RV16 on mRNA expression of these peptides in PBEC. In line with this, PBEC were found to express TLR3, a Toll-like receptor involved in recognition of dsRNA. This study shows that rhinovirus infection of PBEC leads to increased hBD-2 and hBD-3 mRNA expression, which may play a role in both the uncomplicated common cold and in virus-associated exacerbations of asthma.     

TLR4-MyD88/Mal-NF-kB Axis Is Involved in Infection of HSV-2 in Human Cervical Epithelial Cells

We have established an in vitro HSV-2 acute infection model with Human cervical epithelial (HCE cells, the primary target and natural host cells for HSV-2) to investigate the role of TLRs-mediated innate immune response to HSV-2. In current study, we found that HSV-2 infection induced activity of NF-kB reporter and expression of cytokines are TLR4-dependent using approaches with shRNA and TLR4 antagonist. Knockdown experiments demonstrated that the adaptor molecules MyD88 and Mal of the TLRs signaling pathway are required in the HSV-2 induced TLR4-dependent NF-kB activation in HCE cells. Western blot assay suggested that knockdown of TLR4 decreased the phosphorylation of IRAK1 and inhibitor of NF-kB (IkB-α) upon HSV-2 infection. Finally, decreased expression of either TLR4 or MyD88/Mal alone or both significantly abolished productions of IL-6 and IFN-β by ELISA analysis. Taken together, our results from the in vitro infection model reveal for the first time that there exists the pathway via TLR4-Mal/MyD88-IRAK1-NF-kB axis in human cervical epithelial cells in response to HSV-2 infection.     

Functional diversification of the toll-like receptor gene family

Phylogenetic analyses supported the hypothesis that the vertebrate toll-like receptors (TLRs) include two very ancient groups that arose by gene duplication prior to the divergence of protostomes and deuterostomes: (1) the TLR1 family (including mammalian TLR1, TLR2, TLR6, and TLR10); and (2) a clade including the remainder of mammalian TLRs. Correlating data on ligand type, subcellular localization, and gene expression in leukocytes and other tissues with the phylogeny provided evidence that certain major functional specializations within the TLRs occurred after ancient gene duplication events and that these traits have been retained through further events of gene duplication. For example, the recognition of bacterial lipoproteins appears to have arisen in the ancestor of the TLR1 family and continues to characterize members of that family whose ligands are known. Likewise, expression on the endosomal membrane and the recognition of nucleic acids appears to have been arisen in the ancestor of the TLR7 family and some related TLRs. On the other hand, gene expression patterns across tissues appear to have been much more volatile over the evolution of the vertebrate TLRs, since genes may show expression profiles similar to those of distantly related genes but dissimilar to those of closely related genes. Thus, the vertebrate TLRs provide an example of a multi-gene family in which gene duplication has been followed by extensive changes in certain aspects of gene function, while others have been conserved throughout vertebrate history. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Suppression of Molecular Inflammatory Pathways by Toll-Like Receptor 7, 8, and 9 Antagonists in a Model of IL-23-Induced Skin Inflammation

Psoriasis is a complex inflammatory disease resulting from the activation of T helper (Th) 1 and Th17 cells. Recent evidence suggests that abnormal activation of Toll-like receptors (TLRs) 7, 8 and 9 contributes to the initiation and maintenance of psoriasis. We have evaluated the effects of TLR antagonists on the gene expression profile in an IL-23-induced skin inflammation model in mice. Psoriasis-like skin lesions were induced in C57BL/6 mice by intradermal injection of IL-23 in the dorsum. Two TLR antagonists were compared: IMO-3100, an antagonist of TLRs 7 and 9, and IMO-8400, an antagonist of TLRs 7, 8 and 9, both of which previously have been shown to reduce epidermal hyperplasia in this model. Skin gene expression profiles of IL-23-induced inflammation were compared with or without TLR antagonist treatment. IL-23 injection resulted in alteration of 5100 gene probes (fold change ≥ 2, FDR < 0.05) including IL-17 pathways that are up-regulated in psoriasis vulgaris. Targeting TLRs 7, 8 and 9 with IMO-8400 resulted in modulation of more than 2300 mRNAs while targeting TLRs 7 and 9 with IMO-3100 resulted in modulation of more than 1900 mRNAs. Both agents strongly decreased IL-17A expression (>12-fold reduction), normalized IL-17 induced genes such as beta-defensin and CXCL1, and normalized aberrant expression of keratin 16 (indicating epidermal hyperplasia). These results suggest that IL-23-driven inflammation in mouse skin may be dependent on signaling mediated by TLRs 7, 8, and 9 and that these receptors represent novel therapeutic targets in psoriasis vulgaris and other diseases with similar pathophysiology.