Chemokines and allergic disease

Alternative lung cell model systems for toxicology testing strategies: Current knowledge and future outlook

Due to the current relevance of pulmonary toxicology (with focus upon air pollution and the inhalation of hazardous materials), it is important to further develop and implement physiologically relevant models of the entire respiratory tract. Lung model development has the aim to create human relevant systems that may replace animal use whilst balancing cost, laborious nature and regulatory ambition. There is an imperative need to move away from rodent models and implement models that mimic the holistic characteristics important in lung function. The purpose of this review is therefore, to describe and identify the various alternative models that are being applied towards assessing the pulmonary toxicology of inhaled substances, as well as the current and potential developments of various advanced models and how they may be applied towards toxicology testing strategies. These models aim to mimic various regions of the lung, as well as implementing different exposure methods with the addition of various physiologically relevent conditions (such as fluid-flow and dynamic movement). There is further progress in the type of models used with focus on the development of lung-on-a-chip technologies and bioprinting, as well as and the optimization of such models to fill current knowledge gaps within toxicology.

Evidence that geographic variation in genetic ancestry associates with uterine fibroids

Uterine fibroids disproportionately impact Black women. Evidence suggests Black women have earlier onset and higher cumulative risk. This risk disparity may be due an imbalance of risk alleles in one parental geographic ancestry subgroup relative to others. We investigated ancestry proportions for the 1000 Genomes phase 3 populations clustered into 6 geographic groups for association with fibroid traits in Black women (n=583 cases, 797 controls) and White women (n=1,195 cases, 1,164 controls). Global ancestry proportions were estimated using ADMIXTURE. Dichotomous (fibroids status and multiple fibroid status) and continuous outcomes (volume and largest dimension) were modeled for association with ancestry proportions using logistic and linear regression adjusting for age. Effect estimates are reported per 10% increase in genetically inferred ancestry proportion. Among AAs, West African (WAFR) ancestry was associated with fibroid risk, East African ancestry was associated with risk of multiple fibroids, Northern European (NEUR) ancestry was protective for multiple fibroids, Southern European ancestry was protective for fibroids and multiple fibroids, and South Asian (SAS) ancestry was positively associated with volume and largest dimension. In EAs, NEUR ancestry was protective for fibroids, SAS ancestry was associated with fibroid risk, and WAFR ancestry was positively associated with volume and largest dimension. These results suggest that a proportion of fibroid risk and fibroid trait racial disparities are due to genetic differences between geographic groups. Further investigation at the local ancestry and single variant levels may yield novel insights about disease architecture and genetic mechanisms underlying ethnic disparities in fibroid risk.

Allergic Aspects of IgG4-Related Disease: Implications for Pathogenesis and Therapy

IgG4-related disease (IgG4-RD) is a rare systemic fibroinflammatory disease frequently associated with allergy. The pathogenesis of IgG4-RD is poorly understood, and effective therapies are limited. However, IgG4-RD appears to involve some of the same pathogenic mechanisms observed in allergic disease, such as T helper 2 (Th2) and regulatory T cell (Treg) activation, IgG4 and IgE hypersecretion, and blood/tissue eosinophilia. In addition, IgG4-RD tissue fibrosis appears to involve activation of basophils and mast cells and their release of alarmins and cytokines. In this article, we review allergy-like features of IgG4-RD and highlight targeted therapies for allergy that have potential in treating patients with IgG4-RD.

Aronia melanocarpa Fruit Bioactive Fraction Attenuates LPS-Induced Inflammatory Response in Human Bronchial Epithelial Cells

To demonstrate the anti-inflammatory activity of Aronia melanocarpa fruit extract, human bronchial epithelial cells (BEAS-2B) were treated with lipopolysaccharide (LPS) and the effects of aronia bioactive fraction (ABF^®), anthocyanin enriched extract from the fruit of A. melanocarpa, were evaluated. Following pretreatment with ABF^® at 10–25 µg /mL, BEAS-2B cells were exposed to LPS and the expression of inflammatory mediators (tumor necrosis factor [TNF]-α, interleukin [IL]-6, IL-8, regulated upon activation, normal T cell expressed and presumably secreted [RANTES], IL-1β, cyclooxygenase-2 [COX-2], and inducible nitric oxide synthase [iNOS]) was analyzed. In LPS-stimulated BEAS-2B cells, ABF^® pretreatment significantly decreased the mRNA expression of TNF-α, IL-6, IL-8, RANTES, IL-1β, and COX-2 at doses of 10 and 25 µg/mL. ABF^® also attenuated the secretion of TNF- α, IL-6, IL-8, and RANTES protein, as demonstrated by enzyme linked immunosorbent assay. Western blot analyses revealed the decreased expression of COX-2 and iNOS following ABF^® treatment. ROS production was decreased, and the cell cycle was arrested at the G0/G1 and S phases following ABF^® pretreatment. Our results suggest that ABF^® may have potential as a nutraceutical agent for the suppression of airway inflammation.

CFTR Regulates the Proliferation, Migration and Invasion of Cervical Cancer Cells by Inhibiting the NF-κB Signalling Pathway

Background

The cystic fibrosis transmembrane conductance regulator (CFTR) and nuclear factor κB (NF-κB) signalling pathways are currently regarded as co-regulators of the occurrence of cervical cancer. However, the detailed mechanism of CFTR- and NF-κB-mediated effects in cervical cancer remains to be elucidated. This study aimed to investigate the mechanism by which CFTR and NF-κB influence the development of cervical cancer.

Patients and Methods

CFTR ΔF508 mutation and CFTR promoter methylation were detected in cervical tissue samples. NF-κB p65 and IκBα protein levels were tested in HeLa cells with CFTR overexpression and knockdown by Western blotting. The effects of CFTR on cell proliferation, migration, and invasion were examined in HeLa cells by WST-1 and soft agar assays, cell wound scratch assay, and Matrigel invasion assays, respectively. The protein–protein interaction (PPI) network was constructed by using GeneMANIA. GeneCoDis3 was used to perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis on genes in the PPI network.

Results

CFTR mutation and CFTR promoter methylation were not associated with the occurrence of cervical cancer. NF-κB p65 protein levels were decreased in CFTR overexpression lines and increased in CFTR knockdown lines, and IκBα levels were affected in the opposite manner, indicating that CFTR inhibited the NF-κB signalling pathway. CFTR also regulated the cell proliferation, migration, and invasion ability of cervical cancer cells. When CFTR was overexpressed, cell proliferation, migration, and invasion ability were decreased. There were 20 genes that interacted with CFTR. KEGG pathway analysis showed enrichment in the gastric acid secretion, chemokine signalling, bile secretion and apoptosis pathways.

Conclusion

CFTR plays an important role in cancer cell proliferation, migration and invasion by inhibiting the NF-κB signalling pathway in cervical cancer.

Molecular variants of Leishmania (Viannia) braziliensis trigger distinct patterns of cytokines and chemokines expression in golden hamster

Cutaneous leishmaniasis (CL) mainly caused by Leishmania braziliensis is a chronic inflammatory disease widely spread in Brazil. Genetic variant strains of this parasite have been associated with atypical clinical manifestations of CL in an endemic area in Brazil. Furthermore, these strains have presented distinct biological behaviors in golden hamster, suggesting differential activation of the immune response. In the present study we proposed to evaluate the localized immune response in golden hamsters infected with known molecular variant strains of L. braziliensis, in distinct time points post-infection (PI). Detailed analyses of the mRNA expression of cytokines and chemokines in hamster-skin lesions were performed. Heat map matrix and hierarchical cluster analysis were carried out to segregate the strains due to mRNA expression. Distinct patterns of immune response were found in both time points, more evident in the recent-phase disease (30 days-PI). At this time point, the genetic variant strains expressed high levels of tnfα, il12 and tgfβ whilst the non-variant strain expressed ifnγ, il6, il4, il10, il13 and ccl17. The hierarchical clustering highlights this distinct pattern in which all genetic variant strain was grouped in the cluster I and the non-variant strain grouped into the cluster II. At late-phase disease (60 days-PI) all isolates expressed high levels of il4 and il10. The non-variant strain shown a significant reduced expression of ifnγ, il6, ccl17, and ccl22 whilst distinct patterns were observed for the genetic variant strains. For the first time, a large panel of cytokines and chemokines mRNA-expression was analyzed in experimental trials using golden hamsters as animal model and genetic variant strains of L. braziliensis. Our findings suggest that genetic variant strains of L. braziliensis are able to trigger differential gene expression of cytokines and chemokines in the skin lesion from infected hamsters. The parasite intrinsic ability to activate distinct pathways in the host-parasite interaction may be associated to the large spectrum of clinical manifestation observed in CL-patients.

Serum cytokine and chemokine profiles in patients with juvenile muscular atrophy of distal upper extremity (Hirayama disease)

Juvenile muscular atrophy of the distal upper extremity (Hirayama disease) is characterized by adolescent-onset muscular weakness of the distal upper limb. Several studies showed the contribution of atopic disposition and hyperIgEaemia to the disease process, but it has not been well clarified. To identify cytokine and chemokine profiles in Hirayama disease, serum samples were analyzed using multiplex magnetic bead-based assay. Eotaxin, MCP-1 and RANTES levels were significantly higher in Hirayama disease (N=11) than in normal controls (N=12). These chemokines are associated with inflammatory cell recruitment. Allergic inflammation may involve in the pathogenesis of Hirayama disease.

Specific allergen immunotherapy: effect on IgE, IgG4 and chemokines in patients with allergic rhinitis

BACKGROUND

Allergen-specific immunotherapy (SIT) is considered as the most effective treatment for Immunoglobulin E (IgE)-mediated allergies. However, how specific immunotherapy attenuates allergic responses is still not clear, but could potentially involve cytokines as well as IgG4-mediated responses. Based on the role of chemokines in IgE-mediated inflammation, we examined the SIT-induced chemokine response in patients with allergic rhinitis.

METHODS

We included 35 patients with allergic rhinitis; 20 patients received SIT and 15 patients were not treated with specific immunotherapy. The patients were followed for 3 years. Blood samples were collected before SIT and 3, 5, 7 and 21 weeks and 1, 2 and 3 years after the start of therapy. Total IgE, specific IgE, IgG4 and chemokine levels were assessed.

RESULTS

Our main findings were: (i) SIT was associated with an early increase in total and specific IgE during the first 7 weeks, with a subsequent decline, accompanied by a marked increase in specific IgG4 when IgE started to decline; (ii) these SIT-induced responses were accompanied by and in some degree correlated with increased plasma concentrations of the chemokines, monocyte chemoattractant protein (MCP)-1, and eotaxin; and (iii) within the SIT group, these correlations with chemokines were restricted to IgE and IgG4 against birch tree pollen.

CONCLUSION

Our findings further support a role for IgG4-mediated mechanisms in the beneficial effects of SIT in patients with allergic rhinitis (AR) and that increased levels of certain chemokines also could be of importance for the effect of such therapy.

Pleiotropic Effects of Immune Responses Explain Variation in the Prevalence of Fibroproliferative Diseases

Many diseases are differentially distributed among human populations. Differential selection on genetic variants in ancestral environments that coincidentally predispose to disease can be an underlying cause of these unequal prevalence patterns. Selected genes may be pleiotropic, affecting multiple phenotypes and resulting in more than one disease or trait. Patterns of pleiotropy may be helpful in understanding the underlying causes of an array of conditions in a population. For example, several fibroproliferative diseases are more prevalent and severe in populations of sub-Saharan ancestry. We propose that this disparity is due to selection for an enhanced Th2 response that confers resistance to helminthic infections, and concurrently increases susceptibility to fibrosis due to the profibrotic action of Th2 cytokines. Many studies on selection of Th2-related genes for host resistance to helminths have been reported, but the pleiotropic impact of this selection on the distribution of fibrotic disorders has not been explicitly investigated. We discuss the disproportionate occurrence of fibroproliferative diseases in individuals of African ancestry and provide evidence that adaptation of the immune system has shaped the genetic structure of these human populations in ways that alter the distribution of multiple fibroproliferative diseases.

RANKL/RANK interaction promotes the growth of cervical cancer cells by strengthening the dialogue between cervical cancer cells and regulation of IL-8 secretion

Receptor activator for nuclear factor κB ligand (RANKL) is a member of the tumor necrosis factor (TNF) family. The interaction between RANKL and its receptor RANK plays an important role in the development and function of diverse tissues. However, the expression and role of RANKL in cervical cancer are still unknown. In the present study, we found that RANKL and RANK were highly co-expressed in cervical cancer. HeLa and SiHa cells secreted soluble RANKL (sRANKL), expressed member RANKL (mRANKL) and RANK. Recombinant human RANKL protein had no effect on the viability of HeLa and SiHa cells. Yet, blocking RANKL with an anti-human RANKL neutralizing antibody (α-RANKL) or recombinant human osteoprotegrin (OPG) protein resulted in the downregulation of Ki-67 and B-cell lymphoma 2 (Bcl-2) expression and an increase in Fas and Fas ligand (FasL) expression, as well as a high level of viability and a low level of apoptosis in the HeLa and SiHa cells. In addition, α-RANKL led to a decrease in IL-8 secretion. Recombinant human IL-8 protein reversed the effect of α-RANKL on the expression of proliferation- and apoptosis‑related molecules, and proliferation and apoptosis in the HeLa and SiHa cells. The present study suggests that a high level of mRANKL/RANK expression in cervical cancer lesions plays an important role in the rapid growth of cervical cancer cells possibly through strengthening the dialogue between cervical cancer cells and regulation of IL-8 secretion, which may be a possible target for cervical cancer therapy.

Serotonin 5-HT₂ receptor activation prevents allergic asthma in a mouse model

Asthma is an inflammatory disease of the lung characterized by airways hyper-responsiveness (AHR), inflammation, and mucus hyperproduction. Current mainstream therapies include bronchodilators that relieve bronchoconstriction and inhaled glucocorticoids to reduce inflammation. The small molecule hormone and neurotransmitter serotonin has long been known to be involved in inflammatory processes; however, its precise role in asthma is unknown. We have previously established that activation of serotonin 5-hydroxytryptamine (5-HT)(2A) receptors has potent anti-inflammatory activity in primary cultures of vascular tissues and in the whole animal in vasculature and gut tissues. The 5-HT(2A) receptor agonist, (R)-2,5-dimethoxy-4-iodoamphetamine [(R)-DOI] is especially potent. In this work, we have examined the effect of (R)-DOI in an established mouse model of allergic asthma. In the ovalbumin mouse model of allergic inflammation, we demonstrate that inhalation of (R)-DOI prevents the development of many key features of allergic asthma, including AHR, mucus hyperproduction, airways inflammation, and pulmonary eosinophil recruitment. Our results highlight a likely role of the 5-HT2 receptors in allergic airways disease and suggest that 5-HT2 receptor agonists may represent an effective and novel small molecule-based therapy for asthma.

Oncolytic tanapoxvirus expressing FliC causes regression of human colorectal cancer xenografts in nude mice

Colorectal cancers are significant causes of morbidity and mortality and existing therapies often perform poorly for individuals afflicted with advanced disease. Oncolytic virotherapy is an emerging therapeutic modality with great promise for addressing this medical need. Herein we describe the in vivo testing of recombinant variants of the tanapoxvirus (TPV). Recombinant viruses were made ablated for either the 66R gene (encoding a thymidine kinase), the 2L gene (encoding a TNF-binding protein), or both. Some of the recombinants were armed to express mouse chemotactic protein 1 (mCCL2/mMCP-1), mouse granulocyte-monocyte colony stimulating factor (mGM-CSF), or bacterial flagellin (FliC). Tumors were induced in athymic nude mice by implantation of HCT 116 cells and subsequently treated by a single intratumoral injection of one of the recombinant TPVs. Histological examination showed a common neoplastic cell type and a range of immune cell infiltration, necrosis, and tumor cell organization. Significant regression was seen in tumors treated with virus TPV/Δ2L/Δ66R/fliC, and to a lesser extent the recombinants TPV/Δ2L and TPV/Δ66R. Our results suggest that oncolytic recombinants of the TPV armed with activators of the innate immune response may be effective virotherapeutic agents for colorectal cancers in humans and should be explored further to fully realize their potential.

(+)-Nootkatone inhibits tumor necrosis factor α/interferon γ-induced production of chemokines in HaCaT cells

Chemokines are important mediators of cell migration, and thymus and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22) are well-known typical inflammatory chemokines involved in atopic dermatitis (AD). (+)-Nootkatone is the major component of Cyperus rotundus. (+)-Nootkatone has antiallergic, anti-inflammatory, and antiplatelet activities. The purpose of this study was to investigate the effect of (+)-nootkatone on tumor necrosis factor α (TNF-α)/interferon γ (IFN-γ)-induced expression of Th2 chemokines in HaCaT cells. We found that (+)-nootkatone inhibited the TNF-α/IFN-γ-induced expression of TARC/CCL17 and MDC/CCL22 mRNA in HaCaT cells. It also significantly inhibited TNF-α/IFN-γ-induced activation of nuclear factor kappa B (NF-κB), p38 mitogen-activated protein kinase (MAPK), and protein kinase Cζ (PKCζ). Furthermore, we showed that PKCζ and p38 MAPK contributed to the inhibition of TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression by blocking IκBα degradation in HaCaT cells. Taken together, these results suggest that (+)-nootkatone may suppress TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression in HaCaT cells by inhibiting of PKCζ and p38 MAPK signaling pathways that lead to activation of NF-κB. We propose that (+)-nootkatone may be a useful therapeutic candidate for inflammatory skin diseases such as AD.

Eosinophilic esophagitis: an immune-mediated esophageal disease

Eosinophilic esophagitis (EoE) is an emerging disease defined by esophageal dysfunction, by typical endoscopic findings and by abnormal eosinophilic inflammation within the esophagus. Eosinophilic accumulation in the esophagus occurs as a result of esophageal overexpression of pro-inflammatory mediators, including T cells and mast cells, cytokines such as interleukin (IL)-13, IL-5 and IL-15, as well as chemoattractants (eotaxin and transforming growth factor-β1, fibroblast growth factor and the newly characterized gene--thymic stromal lymphopoietin, which is a key regulator of allergic sensitization initiation). The role of allergy, particularly food allergy in EoE is indisputable, as elimination diet is a proven commonly used treatment for the disease. However, unlike classical immediate IgE-mediated reaction to allergen, EoE is associated with an altered immune response, characterized by a combination of IgE-mediated and non-IgE-mediated mechanisms. In this review, we aim to discuss the many typical aspects of EoE as opposed to other entities involving the esophagus, with focusing on the aberrant immune-mediated key players contributing to the pathogenesis of this unique disease.

Cigarette smoke modulates expression of human rhinovirus-induced airway epithelial host defense genes

Human rhinovirus (HRV) infections trigger acute exacerbations of chronic obstructive pulmonary disease (COPD) and asthma. The human airway epithelial cell is the primary site of HRV infection and responds to infection with altered expression of multiple genes, the products of which could regulate the outcome to infection. Cigarette smoking aggravates asthma symptoms, and is also the predominant risk factor for the development and progression of COPD. We, therefore, examined whether cigarette smoke extract (CSE) modulates viral responses by altering HRV-induced epithelial gene expression. Primary cultures of human bronchial epithelial cells were exposed to medium alone, CSE alone, purified HRV-16 alone or to HRV-16+ CSE. After 24 h, supernatants were collected and total cellular RNA was isolated. Gene array analysis was performed to examine mRNA expression. Additional experiments, using real-time RT-PCR, ELISA and/or western blotting, validated altered expression of selected gene products. CSE and HRV-16 each induced groups of genes that were largely independent of each other. When compared to gene expression in response to CSE alone, cells treated with HRV+CSE showed no obvious differences in CSE-induced gene expression. By contrast, compared to gene induction in response to HRV-16 alone, cells exposed to HRV+CSE showed marked suppression of expression of a number of HRV-induced genes associated with various functions, including antiviral defenses, inflammation, viral signaling and airway remodeling. These changes were not associated with altered expression of type I or type III interferons. Thus, CSE alters epithelial responses to HRV infection in a manner that may negatively impact antiviral and host defense outcomes.

Langerhans cells are critical in epicutaneous sensitization with protein antigen via thymic stromal lymphopoietin receptor signaling

BACKGROUND

The clarification of cutaneous dendritic cell subset and the role of thymic stromal lymphopoietin (TSLP) signaling in epicutaneous sensitization with protein antigens, as in the development of atopic dermatitis, is a crucial issue.

OBJECTIVES

Because TSLP is highly expressed in the vicinity of Langerhans cells (LCs), we sought to clarify our hypothesis that LCs play an essential role in epicutaneous sensitization with protein antigens through TSLP signaling.

METHODS

By using Langerin-diphtheria toxin receptor knock-in mice and human Langerin-diphtheria toxin A transgenic mice, we prepared mice deficient in LCs. We also prepared mice deficient in TSLP receptors in LCs by using TSLP receptor-deficient mice with bone marrow chimeric technique. We applied these mice to an ovalbumin (OVA)-induced epicutaneous sensitization model.

RESULTS

Upon the epicutaneous application of OVA, conditional LC depletion attenuated the development of clinical manifestations as well as serum OVA-specific IgE increase, OVA-specific T-cell proliferation, and IL-4 mRNA expression in the draining lymph nodes. Consistently, even in the steady state, permanent LC depletion resulted in decreased serum IgE levels, suggesting that LCs mediate the T(H)2 local environment. In addition, mice deficient in TSLP receptors on LCs abrogated the induction of OVA-specific IgE levels upon epicutaneous OVA sensitization.

CONCLUSION

LCs initiate epicutaneous sensitization with protein antigens and induce T(H)2-type immune responses via TSLP signaling.

Excess risk of temporomandibular disorder associated with cigarette smoking in young adults

Evidence suggests that the effect of cigarette smoking on chronic pain is stronger in younger than older adults. This case-control study investigated whether age modified an effect of smoking on temporomandibular disorder (TMD) in 299 females aged 18 to 60 years. It also investigated the extent to which this relationship was explained by psychological profile, inflammatory response, and allergy. Cases were defined using the Research Diagnostic Criteria for Temporomandibular Disorders based on clinical examination. Psychological profile was evaluated using standardized instruments. Inflammatory response was evaluated with 11 cytokines isolated in plasma. History of allergy conditions was self-reported. Odds ratios (ORs) for the effect of smoking were calculated using binary logistic regression. Stratified analyses and the likelihood ratio test examined effect modification by smoking. Compared with nonsmokers, ever smokers aged <30 years had higher odds of TMD (OR = 4.14, 95% CI: 1.57, 11.35) than older adults (OR = 1.23, 95% CI: .55, 2.78) (P (effect modification) = .038). Adjustment for psychological profile, cytokines, and history of allergy-like conditions attenuated the effect by 45% to statistical nonsignificance. The main finding was reproduced with secondary analyses of 2 nationally representative surveys of adults conducted in the US and Australia.

PERSPECTIVE

This study showed that smoking was associated with TMD risk in females, but only in young adulthood. It replicated this finding in 2 nationally representative surveys of females in the US and Australia. Findings may alert clinicians to recognize that smoking is a concern for TMD in younger female patients.

Olopatadine hydrochloride and rupatadine fumarate in seasonal allergic rhinitis: A comparative study of efficacy and safety

Objective:

To compare the efficacy and safety of olopatadine and rupatadine in seasonal allergic rhinitis (SAR).

Materials and Methods:

A 2-week, single-centered, randomized, open, parallel group comparative clinical study was conducted on patients with SAR. Following inclusion and exclusion criteria, 70 patients were recruited and were randomized to two treatment groups and received the respective drugs for 2 weeks. At follow-up, clinical improvement was assessed in terms of change in total and differential count of leucocytes, serum Immunoglobulin E (IgE) level, Total Nasal Symptom Score (TNSS) and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scoring.

Results:

Both the drugs significantly reduced the differential count (P<0.001) and absolute eosinophil count (P<0.001), but olopatadine was found to be superior. In olopatadine group, there was significantly higher reduction in serum IgE (P=0.01), TNSS (P<0.001) and RQLQ score (P=0.015) than that of rupatadine. Incidence of adverse effects was found to be less in olopatadine group when compared with rupatadine group.

Conclusions:

Olopatadine is a better choice in SAR in comparison to rupatadine due to its better efficacy and safety profile.

Psidium guajava extract inhibits thymus and activation-regulated chemokine (TARC/CCL17) production in human keratinocytes by inducing heme oxygenase-1 and blocking NF-κB and STAT1 activation

Psidium guajava (P. guajava) is a food and medicinal plant with antioxidant, anti-inflammatory, and anti-allergic activities that support its traditional uses. The aim of this study was to determine the effects of P. guajava ethyl acetate extract (PGEA) on atopic dermatitis and to investigate the possible mechanisms by which PGEA inhibits cytokine-induced Th2 chemokine expression in HaCaT human keratinocyte cells. We found that PGEA suppressed the IFN-γ/TNF-α-co-induced production of thymus and activation-regulated chemokine (TARC) protein and mRNA in HaCaT cells. Additionally, PGEA inhibited the TNF-α/IFN-γ-co-induced activation of NF-κB and STAT1 and increased the expression of heme oxygenase-1 (HO-1) protein and mRNA. HO-1 inhibitor enhanced the suppressive effects of PGEA on TNF-α/IFN-γ-co-induced TARC production and gene expression. Collectively, these data demonstrate that PGEA inhibits chemokine expression in keratinocytes by inducing HO-1 expression and it suggests a possible therapeutic application in atopic dermatitis and other inflammatory skin diseases.

Bambusae caulis in Liquamen Suppresses the Expression of Thymus and Activation-Regulated Chemokine and Macrophage-Derived Chemokine in Human Keratinocytes due to Antioxidant Effect

Bambusae caulis in Liquamen (BCL), traditional herbal medicine used in East Asia, is known to have antioxidative and immune-regulating properties. We hypothesized that the potential antioxidant effects of BCL might suppress the production of thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) in human keratinocytes (HaCaT cell). The immune-regulating effect of BCL was demonstrated by antioxidant capacity using DPPH analysis and DCFH-DA analysis. We found that BCL had strong ROS scavenge effect in HaCaT cell. BCL also showed suppression of IFN-γ-induced expression of TARC and MDC, activation of NF-κB, and, moreover, significant block of IFN-γ-induced degradation and phosphorylation of IκB. However, it had no effects on phosphorylation of p38 MAPK. Collectively, these results suggest that BCL may have a therapeutic potential on skin disease such as atopic dermatitis by inhibiting Th2 chemokines which is due, at least in part, to its antioxidant capacities.

Modulation of epithelial biology by rhinovirus infection: role in inflammatory airway diseases

The human airway epithelial cell is the primary site of human rhinovirus (HRV) infection in both the upper and lower airways, but HRV infection does not cause overt epithelial cytotoxicity at either location. Therefore, it is thought that HRV infections induce symptoms of the common cold or exacerbate lower airway diseases, such as asthma and chronic obstructive pulmonary disease, by altering epithelial cell biology. This premise has led to intense investigation of the interactions of HRV with epithelial cells. This article reviews current knowledge regarding how HRV induces epithelial induction of proinflammatory cytokines and chemokines. In addition, the contributions of epithelial cells to host antiviral responses will be reviewed along with evidence that HRV-infected epithelial cells may contribute to the airway remodeling that is a characteristic feature of asthma.

Sulforaphane suppresses TARC/CCL17 and MDC/CCL22 expression through heme oxygenase-1 and NF-κB in human keratinocytes

Sulforaphane (4-methylsulfinylbutyl isothiocyanate, SFN) from broccoli has been used a chemopreventive photochemical as detoxification of xenobiotics and anti-inflammatory, however, there is no studies for Th2 chemokine expression through heme oxygenase-1 and NF-κB in keratinocytes. Atopic dermatitis is a chronically relapsing pruritic inflammatory skin disease. SFN is demonstrated to have anti-inflammatory and anti-oxidant effects. This study aimed to define whether and how SFN regulates Th2-related chemokine production in human HaCaT keratinocytes. The level of chemokine expression was measured by reverse transcription polymerase chain reaction (RT-PCR) and signaling study was performed by Western blot analysis. Chemokine production was determined by enzyme-linked immunosorbent assay. Pretreatment with SFN suppressed interferon-γ (IFN-γ) and tumor necrosis factor (TNF)-α- induced thymus- and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22) production in HaCaT keratinocytes. SFN inhibited IFN-γ and TNF-α-induced NF-κB activation as well as STAT1 activation. Interestingly, pretreatment with SFN result in significantly suppressed IFN-γ and TNF-α-induced TARC/CCL17 and MDC/CCL22 production through the induction of HO-1. This suppression was completely abolished by HO-1 siRNA. Furthermore, Carbon monoxide, but not other end products of HO-1 activity, also suppressed IFN-γ and TNF-α-induced TARC/CCL17 and MDC/CCL22 production. These results demonstrate that SFN has an inhibitory role in IFN-γ and TNF-α-induced production of TARC/CCL17 and MDC/CCL22 in human HaCaT cells by inhibition of NF-κB activation and induction of HO-1.

Lysophosphatidic acid inhibits CC chemokine ligand 5/RANTES production by blocking IRF-1-mediated gene transcription in human bronchial epithelial cells

Lysophosphatidic acid (LPA) is a phospholipid mediator that exerts a variety of biological responses through specific G-protein-coupled receptors (LPA(1)-LPA(5) and P2Y5). LPA is thought to be involved in airway inflammation by regulating the expression of anti-inflammatory and proinflammatory genes. Chemokines such as CCL5/RANTES are secreted from airway epithelium and play a key role in allergic airway inflammation. CCL5/RANTES is a chemoattractant for eosinophils, T lymphocytes, and monocytes and seems to exacerbate asthma. We stimulated CCL5/RANTES production in a human bronchial epithelial cell line, BEAS-2B, with IFN-γ and TNF-α. When LPA was added, CCL5/RANTES mRNA expression and protein secretion were inhibited, despite the presence of IFN-γ and TNF-α. The LPA effect was attenuated by Ki16425, a LPA(1)/LPA(3) antagonist, but not by dioctylglycerol pyrophosphate 8:0, an LPA(3) antagonist. Pertussis toxin, the inhibitors for PI3K and Akt also attenuated the inhibitory effect of LPA on CCL5/RANTES secretion. We also identify the transcription factor IFN regulatory factor-1 (IRF-1) as being essential for CCL5/RANTES production. Interestingly, LPA inhibited IFN-γ and TNF-α-induced IRF-1 activation by blocking the binding of IRF-1 to its DNA consensus sequence without changing IRF-1 induction and its nuclear translocation. Ki16425, pertussis toxin, and PI3K inhibitors attenuated the inhibitory effect of LPA on IRF-1 activation. Our results suggest that LPA inhibits IFN-γ- and TNF-α-induced CCL5/RANTES production in BEAS-2B cells by blocking the binding of IRF-1 to the CCL5/RANTES promoter. LPA(1) coupled to G(i) and activation of PI3K is required for this unique effect.

MCP-1: chemoattractant with a role beyond immunity: a review

BACKGROUND

Monocyte Chemoattractant Protein (MCP)-1, a potent monocyte attractant, is a member of the CC chemokine subfamily. MCP-1 exerts its effects through binding to G-protein-coupled receptors on the surface of leukocytes targeted for activation and migration. Role of MCP-1 and its receptor CCR2 in monocyte recruitment during infection or under other inflammatory conditions is well known.

METHOD

A comprehensive literature search was conducted from the websites of the National Library of Medicine (http://www.ncbl.nlm.nih.gov) and Pubmed Central, the US National Library of Medicine's digital archive of life sciences literature (http://www.pubmedcentral.nih.gov/). The data was assessed from books and journals that published relevant articles in this field.

RESULT

Recent and ongoing research indicates the role of MCP-1 in various allergic conditions, immunodeficiency diseases, bone remodelling, and permeability of blood - brain barrier, atherosclerosis, nephropathies and tumors.

CONCLUSION

MCP-1 plays an important role in pathogenesis of various disease states and hence MCP-1 inhibition may have beneficial effects in such conditions.

Aberrant inflammatory response to Streptococcus pyogenes in mice lacking myeloid differentiation factor 88

Several in vitro studies have emphasized the importance of toll-like receptor/myeloid differentiation factor 88 (MyD88) signaling in the inflammatory response to Streptococcus pyogenes. Since the extent of inflammation has been implicated in the severity of streptococcal diseases, we have examined here the role of toll-like receptor/MyD88 signaling in the pathophysiology of experimental S. pyogenes infection. To this end, we compared the response of MyD88-knockout (MyD88(-/-)) after subcutaneous inoculation with S. pyogenes with that of C57BL/6 mice. Our results show that MyD88(-/-) mice harbored significantly more bacteria in the organs and succumbed to infection much earlier than C57BL/6 animals. Absence of MyD88 resulted in diminished production of inflammatory cytokines such as interleukin-12, interferon-gamma, and tumor necrosis factor-alpha as well as chemoattractants such as monocyte chemotactic protein-1 (MCP-1) and Keratinocyte-derived chemokine (KC), and hampered recruitment of effector cells involved in bacterial clearance (macrophages and neutrophils) to the infection site. Furthermore, MyD88(-/-) but not C57BL/6 mice exhibited a massive infiltration of eosinophils in infected organs, which can be explained by an impaired production of the regulatory chemokines, gamma interferon-induced monokine (MIG/CXCL9) and interferon-induced protein 10 (IP-10/CXCL10), which can inhibit transmigration of eosinophils. Our results indicate that MyD88 signaling targets effector cells to the site of streptococcal infection and prevents extravasation of cells that can induce tissue damage. Therefore, MyD88 signaling may be important for shaping the quality of the inflammatory response elicited during infection to ensure optimal effector functions.

Ca2+ signaling in airway epithelial cells facilitates leukocyte recruitment and transepithelial migration

In airway cells, TLR2 stimulation by bacterial products activates Ca2+ fluxes that signal leukocyte recruitment to the lung and facilitates transepithelial migration into the airway lumen. TLR2 is apically displayed on airway cells, where it senses bacterial stimuli. Biochemical and genetic approaches demonstrate that TLR2 ligands stimulate release of Ca2+ from intracellular stores by activating TLR2 phosphorylation by c-Src and recruiting PI3K and PLCgamma to affect Ca2+ release through IP3Rs. This Ca2+ release plays a pivotal role in signaling TLR2-dependent NF-kappaB activation and chemokine expression to recruit PMNs to the lung. In addition, TLR2-initiated Ca2+ release activates Ca2+-dependent proteases, calpains, which cleave the transmembrane proteins occludin and E-cadherin to promote PMN transmigration. This review highlights recent findings that demonstrate a central role for Ca2+ signaling in airway epithelial cells to induce proinflammatory gene transcription and to initiate junctional changes that accommodate transmigration of recruited PMNs.

The adenylyl cyclase-cAMP system suppresses TARC/CCL17 and MDC/CCL22 production through p38 MAPK and NF-kappaB in HaCaT keratinocytes

Patients with atopic dermatitis (AD) have significantly reduced plasma cAMP levels, and the cAMP level is correlated with the immunopathogenesis of AD. The production of thymus and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22) in keratinocytes is significantly enhanced in patients with AD. In the present study, we investigated the in vitro effects of the adenylyl cyclase-cAMP system on IFN-gamma and TNF-alpha-stimulated production of TARC and MDC in human HaCaT keratinocytes. Both forskolin (a direct activator of adenylyl cyclase) and dibutyryl-cAMP (DBcAMP, a permeable analog of cAMP) suppressed production of TARC and MDC in parallel with the activation of NF-kappaB in IFN-gamma and TNF-alpha-stimulated HaCaT cells. Moreover, inhibition of NF-kappaB suppressed TARC and MDC production induced by IFN-gamma plus TNF-alpha. However, dideoxyforskolin, a forskolin derivative that does not activate cAMP, failed to suppress the secretion of these chemokines. An inhibitor of p38 MAPK suppressed the production of TARC and MDC in parallel to the activation of NF-kappaB in HaCaT cells. Of note, the IFN-gamma plus TNF-alpha-stimulated activation of p38 MAPK was suppressed following incubation with forskolin or DBcAMP alone. These results indicate that the adenylyl cyclase-cAMP system has an inhibitory role in IFN-gamma plus TNF-alpha-stimulated production of TARC and MDC in HaCaT keratinocytes by inhibiting NF-kappaB activation through p38 MAPK pathway, implying that the adenylyl cyclase-cAMP system could be a candidate therapeutic target of Th2-skewed skin inflammation such as AD.

Post-transcriptional silencing of CCR3 downregulates IL-4 stimulated release of eotaxin-3 (CCL26) and other CCR3 ligands in alveolar type II cells

Trafficking and inflammation in airway diseases are, in part, modulated by members of the CC chemokine family, eotaxin-1 (CCL11), eotaxin-2 (CCL24), and eotaxin-3 (CCL26), which transduce signals through their CCR3 receptor. In this context, we hypothesized that transfecting alveolar type II epithelial cells with CCR3-targeted siRNA or antisense (AS-ODN) sequences will downregulate cellular synthesis and release of the primary CCR3 ligands CCL26 and CCL24 and will modulate other CCR3 ligands. The human A549 alveolar type II epithelium-like cell culture model was used for transfection and subsequent effects on CCR3 agonists. siRNAs were particularly effective. PCR showed a 60-80% decrease in mRNA and immunoblots showed up to 75-84% reduction of CCR3 in siRNA treated cells. CCR3-siRNA treatments reduced IL-4 stimulated CCL26 release and constitutive CCL24 release by 65% and 80%, respectively. Release of four additional CCR3 agonists RANTES, MCP-2, MCP-3 and MCP-4 was also significantly reduced by CCR3-siRNA treatments of the alveolar type II cells. Activation of eosinophils, assessed as superoxide anion generation, was reduced when eosinophils were treated with supernatants of A549 cells pretreated with CCR3-targeted siRNAs or AS-ODNs. Collectively, the data suggest that post-transcriptional regulation of CCR3 receptors may be a potential therapeutic approach for interrupting proinflammatory signaling.

Coordinated changes in mRNA turnover, translation, and RNA processing bodies in bronchial epithelial cells following inflammatory stimulation

Bronchial epithelial cells play a pivotal role in airway inflammation, but little is known about posttranscriptional regulation of mediator gene expression during the inflammatory response in these cells. Here, we show that activation of human bronchial epithelial BEAS-2B cells by proinflammatory cytokines interleukin-4 (IL-4) and tumor necrosis factor alpha (TNF-alpha) leads to an increase in the mRNA stability of the key chemokines monocyte chemotactic protein 1 and IL-8, an elevation of the global translation rate, an increase in the levels of several proteins critical for translation, and a reduction of microRNA-mediated translational repression. Moreover, using the BEAS-2B cell system and a mouse model, we found that RNA processing bodies (P bodies), cytoplasmic domains linked to storage and/or degradation of translationally silenced mRNAs, are significantly reduced in activated bronchial epithelial cells, suggesting a physiological role for P bodies in airway inflammation. Our study reveals an orchestrated change among posttranscriptional mechanisms, which help sustain high levels of inflammatory mediator production in bronchial epithelium during the pathogenesis of inflammatory airway diseases.

Gene encoding Duffy antigen/receptor for chemokines is associated with asthma and IgE in three populations

RATIONALE

Asthma prevalence and severity are high among underserved minorities, including those of African descent. The Duffy antigen/receptor for chemokines is the receptor for Plasmodium vivax on erythrocytes and functions as a chemokine-clearing receptor. Unlike European populations, decreased expression of the receptor on erythrocytes is common among populations of African descent, and results from a functional T-46C polymorphism (rs2814778) in the promoter. This variant provides an evolutionary advantage in malaria-endemic regions, because Duffy antigen/receptor for chemokines-negative erythrocytes are more resistant to infection by P. vivax.

OBJECTIVES

To determine the role of the rs2814778 polymorphism in asthma and atopy as measured by total serum IgE levels among four populations of African descent (African Caribbean, African American, Brazilian, and Colombian) and a European American population.

METHODS

Family-based association tests were performed in each of the five populations to test for association between the rs2814778 polymorphism and asthma or total IgE concentration.

MEASUREMENTS AND MAIN RESULTS

Asthma was significantly associated with the rs2814778 polymorphism in the African Caribbean, Colombian, and Brazilian families (P < 0.05). High total IgE levels were associated with this variant in African Caribbean and Colombian families (P < 0.05). The variant allele was not polymorphic among European Americans.

CONCLUSIONS

Susceptibility to asthma and atopy among certain populations of African descent is influenced by a functional polymorphism in the gene encoding Duffy antigen/receptor for chemokines. This genetic variant, which confers resistance to malarial parasitic infection, may also partially explain ethnic differences in morbidity of asthma.

Gene profiling of keloid fibroblasts shows altered expression in multiple fibrosis-associated pathways

Keloids are benign tumors of the dermis that form during a protracted wound healing process. Susceptibility to keloid formation occurs predominantly in people of African and Asian descent. The key alteration(s) responsible for keloid formation has not been identified and there is no satisfactory treatment for this disorder. The altered regulatory mechanism is limited to dermal wound healing, although several diseases characterized by an exaggerated response to injury are prevalent in individuals of African ancestry. We have observed a complex pattern of phenotypic differences in keloid fibroblasts grown in standard culture medium or induced by hydrocortisone (HC). In this study Affymetrix-based microarray was performed on RNA obtained from fibroblasts cultured from normal scars and keloids grown in the absence and presence of HC. We observed differential regulation of approximately 500 genes of the 38,000 represented on the Affymetrix chip. Of particular interest was increased expression of several IGF-binding and IGF-binding-related proteins and decreased expression of a subset of Wnt pathway inhibitors and multiple IL-1-inducible genes. Increased expression of connective tissue growth factor and insulin-like growth factor binding protein-3 was observed in keloid fibroblasts only in the presence of HC. These findings support a role for multiple fibrosis-related pathways in the pathogenesis of keloids.

Genetic susceptibility to atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disorder with an increasing prevalence in industrialized countries. AD belongs to the group of allergic disorders that includes food allergy, allergic rhinitis, and asthma. A multifactorial background for AD has been suggested, with genetic as well as environmental factors influencing disease development. Recent breakthroughs in genetic methodology have greatly augmented our understanding of the contribution of genetics to susceptibility to AD. A candidate gene association study is a general approach to identify susceptibility genes. Fifty three candidate gene studies (50 genes) have identified 19 genes associated with AD risk in at least one study. Significant associations between single nucleotide polymorphisms (SNPs) in chemokines (chymase 1-1903A > G), cytokines (interleukin13 Arg144Gln), cytokine receptors (interleukin 4 receptor 1727G > A) and SPINK 1258G > A have been replicated in more than one studies. These SNPs may be promising for identifying at-risk individuals. SNPs, even those not strongly associated with AD, should be considered potentially important because AD is a common disease. Even a small increase in risk can translate to a large number of AD cases. Consortia and international collaborative studies, which may maximize study efficacy and overcome the limitations of individual studies, are needed to help further illuminate the complex landscape of AD risk and genetic variations.

Immunology

The concept of forbidden foods that should not be eaten goes back to the Garden of Eden and apart from its religious meanings it may also have foreshadowed the concept of foods that can provoke adverse reactions. Thus we could say that allergic diseases have plagued mankind since the beginning of life on earth. The prophet Job was affected by a condition that following the rare symptoms described by the Holy Bible might be identified as a severe form of atopic dermatitis (AD). The earliest record of an apparently allergic reaction is 2621 B.C., when death from stinging insects was first described by hieroglyphics carved into the walls of the tomb of Pharaoh Menes depicting his death following the sting of a wasp. In 79 A.D., the death of the Roman admiral Pliny the Elder was ascribed to the SO₂-rich gases emanating from the eruption of Mount Vesuvius. Hippocrates (460–377 B.C.) was probably the first to describe how cow’s milk (CM) could cause gastric upset and hives, proposing dietetic measures including both treatment and prevention for CM allergy.

Epithelium: at the interface of innate and adaptive immune responses

Several diseases of the airways have a strong component of allergic inflammation in their cause, including allergic rhinitis, asthma, polypoid chronic rhinosinusitis, eosinophilic bronchitis, and others. Although the roles played by antigens and pathogens vary, these diseases have in common a pathology that includes marked activation of epithelial cells in the upper airways, the lower airways, or both. Substantial new evidence indicates an important role of epithelial cells as both mediators and regulators of innate immune responses and adaptive immune responses, as well as the transition from innate immunity to adaptive immunity. The purpose of this review is to discuss recent studies that bear on the molecular and cellular mechanisms by which epithelial cells help to shape the responses of dendritic cells, T cells, and B cells and inflammatory cell recruitment in the context of human disease. Evidence will be discussed that suggests that secreted products of epithelial cells and molecules expressed on their cell surfaces can profoundly influence both immunity and inflammation in the airways.

The allergic cascade: review of the most important molecules in the asthmatic lung

Asthma is the most common chronic inflammatory disorder of the airways among children. It is a complex clinical disease characterized by airway obstruction, airway inflammation and airway hyperresponsiveness to a variety of stimuli. The development of allergic asthma exists of three phases, namely the induction phase, the early-phase asthmatic reaction (EAR) and the late-phase asthmatic reaction (LAR). Each phase is characterized by the production and interplay of various cell-derived mediators. In the induction phase, T helper cytokines are important in the development of asthma. Most important mediators in the EAR are preformed mediators, newly synthesized lipid mediators and cytokines that are produced by mast cells. During the LAR, inflammatory molecules are produced by various cell types, such as eosinophils, neutrophils, T cells, macrophages, dendritic cells, and structural cells. Chronical inflammation leads to structural changes of the airway architecture. In this review, the most important mediators involved in the induction phase, the early-phase and late-phase asthmatic reaction are discussed.

Plasma RANTES increase during the first month of life independently of the feeding mode

The chemokine RANTES (regulated upon activation, normal T cell expressed and secreted) plays a significant role in the innate immunity, which is particularly important in the neonatal period. In this study, we aimed to investigate the ability of the neonate to increase plasma levels of RANTES in the first month of life, and the possible impact of breast feeding on this ability. The study population consisted of 125 healthy term neonates that were exclusively breast-fed (n = 62) or formula-fed (n = 63) for at least 1 month after birth. Plasma RANTES concentrations (ELISA) as well as circulating leukocytes and platelets were measured on days 1 and 30 of life. Median RANTES concentrations of the total group showed a significant increase between day 1 [1000 (448-2100) pg/mL] and day 30 [3688 (1488-5400) pg/mL, p < 0.0001], as did median total lymphocyte, T-cell, B-cell, NK-cell and eosinophil counts (all p values <0.0001). Monocyte and platelet counts did not change significantly over the neonatal period. Further analysis according to the mode of feeding showed that RANTES levels as well as leukocyte populations and platelet counts did not differ significantly between breast-fed and formula-fed neonates on either day 1 or 30. Healthy term neonates are capable of increasing plasma RANTES levels during the 1st month after birth independently of the mode of feeding.

Immunomodulatory effects of macrolide antibiotics in respiratory disease: therapeutic implications for asthma and cystic fibrosis

The macrolide antibiotics are a family of related 14- or 15-membered lactone ring antibiotics. There has been recent interest in the beneficial effects of these drugs as immune modulators in respiratory conditions in children. Cystic fibrosis (CF) and asthma, both of which occur in childhood, have an underlying inflammatory component and are associated with significant morbidity. The pathogenesis of both conditions is poorly understood but several molecular mechanisms have been suggested. In CF, these mechanisms broadly involve altered chloride transport and alteration of the airway surface liquid with disordered neutrophilic inflammation. There is much evidence for a proinflammatory propensity in CF immune effector and epithelial cells and many studies indicate that macrolides modulate these inflammatory processes. Recent studies have confirmed a clinical improvement in CF following treatment with macrolides, but the exact mechanisms by which they work are unknown. Asthma is likely to represent several different phenotypes but in all of these, airway obstruction, bronchial hyperresponsiveness, and inflammation are central processes. Results from trials using macrolides have suggested an improvement in clinical outcome. The putative mechanisms of macrolide immunomodulatory action include improvement of the primary defense mechanisms, inhibition of the bacteria-epithelial cell interaction, modulation of the signaling pathway and chemokine release, and direct neutrophil effects. Putative mechanisms of phenotypic modulation have also been proposed involving interactions with nitric oxide, endothelin-1, and bronchoconstriction, endothelial growth factors and airway remodeling, and bioactive phospholipids in both CF and asthma. Further characterization of these effects and development of targeted designer drugs will further expand our therapeutic repertoire and lead to improved quality and quantity of life for patients with CF and asthma.

The effect of H1 antagonists carebastine and olopatadine on histamine induced expression of CC chemokines in cultured human nasal epithelial cells

BACKGROUND

CC chemokines have been shown to play an important role in inducing selective recruitment of inflammatory cells into local allergic inflammatory sites. CC chemokines are also known as histamine releasing factors. We previously showed that histamine enhances transcription of CC chemokines from nasal mucosa which leads to further induction of histamine release. This cyclic cascade may cause prolonged allergic inflammation. The aim of this study is to clarify the relationship between histamine and CC chemokine production by using human nasal epithelial cells (HNECs) and to examine the potential of H1 receptor (H1R) antagonists in new therapeutic approaches for the treatment of nasal allergy.

METHODS

HNECs were isolated from the nasal turbinates of patients diagnosed with nasal allergy. HNEC monolayers were cultured for 48 hours with or without histamine (10(-3) to 10(-5) mol/L). Furthermore, an H1R antagonist, either carebastine or olopatadine, was added to the supernatant (10(-3) to 10(-7) mol/L) 30 minutes before incubation with histamine. The expression of Regulated on Activation, Normal T-cell Expressed and Secreted (RANTES) and monocyte chemotactic protein-1 (MCP-1) in the culture media were measured by ELISA.

RESULTS

The release of RANTES and MCP-1 was significantly upregulated by histamine compared with the control group. Both carebastine and olopatadine inhibited the release of CC chemokine production to the control level in both groups.

CONCLUSIONS

This study suggests that the interaction between histamine and CC chemokines may prolong allergic inflammation in human nasal mucosa. We also demonstrate the potential use of H1R antagonists in new therapeutic approaches to the treatment of nasal allergy through inhibiting this histamine-CC chemokine interaction.

CCL17 transgenic mice show an enhanced Th2-type response to both allergic and non-allergic stimuli

CC chemokine ligand (CCL)17 is implicated in the pathogenesis of atopic dermatitis (AD). To study the effect of CCL17 produced by keratinocytes (KC) during inflammation, we created transgenic (Tg) mice in which CCL17 is overexpressed in KC. Th2-type contact hypersensitivity (CHS) was enhanced and Th1-type CHS was suppressed in these mice. Increased numbers of CC chemokine receptor (CCR)4(+) cells and mast cells infiltrated in Tg mice. Levels of IL-4 mRNA were higher and those of IFN-gamma mRNA were lower in both acute and chronic CHS. Higher levels of serum IgE were observed after CHS. Numbers of CCR4(+) cells among PBMC were increased in Tg mice challenged acutely on the trunk. Chronic irritation with croton oil induced dermatitis and an elevation of serum IgE levels. Tg mice showed enhanced ear swelling after tape stripping. CCL17 was thought to modify the inflammation caused by sensitizing reagents as well as irritant reagents by attracting CCR4(+) cells into the lesional skin and creating a Th2-dominant condition. AD-like conditions such as increased number of mast cells and elevated levels of serum IgE were observed. Thus, CCL17 may participate in the pathogenesis of skin diseases such as AD by regulating both allergic and irritant inflammation.

Prostaglandin D2 induces IL-8 and GM-CSF by bronchial epithelial cells in a CRTH2-independent pathway

BACKGROUND

Prostaglandin D(2) (PGD(2)), a major prostanoid produced by activated mast cells, has long been implicated in allergic diseases. PGD(2) demonstrates its effects through two G-protein-coupled receptors, DP and CRTH2. The PGD(2)/CRTH2 system mediates chemotaxis of eosinophils, basophils, and Th2 cells, which are involved in the induction of allergic inflammation. Although recent studies have shown that the specific receptors for PGD(2), DP, and CRTH2 are expressed in various human tissues, the role of PGD(2) is unknown in human bronchial epithelial cells. In this study, we investigated the expression and function of CRTH2/DP on NCI-H(292) and NHBE cells.

METHOD

The CRTH2/DP expression was examined by RT-PCR and flow-cytometric analysis. NCI-H(292) and NHBE cells were cultured in the presence of various stimulants. The resulting supernatants were measured by ELISA.

RESULTS

We demonstrated that PGD(2) induced production of IL-8 and GM-CSF in NCI-H(292) and NHBE cells. DK-PGD(2) (CRTH2 agonist) and latanoprost (FP, a prostaglandin F receptor, agonist) failed to augment the production of these cytokines. Pretreatment with ramatroban (CRTH2 antagonist) and AL8810 (FP antagonist) did not reduce the production of these cytokines. The PGD(2)-induced cytokine production was inhibited by pertussis toxin or specific inhibitors for MAP/ERK kinase (PD98059) and p38 MAP kinase (SB202190).

CONCLUSION

These results suggest that PGD(2) is a potent inducer of IL-8 and GM-CSF production with MAP/ERK and p38 MAP kinase activation, but this is independent of CRTH2 activation.

Pediatric asthmatic patients have low serum levels of monocyte chemoattractant protein-1

Serum levels of MCP-1 were measured in children with and without asthma in order to determine a possible correlation between the MCP-1-2518A/G polymorphism, serum levels of MCP-1 and asthma. Two groups of subjects -160 children with asthma and 158 healthy children were screened with a PCR-based genotyping assay. Serum MCP-1 level was measured by ELISA. The -2518G allele occurred at a significantly higher frequency in asthmatic children than in controls. The mean serum MCP-1 level was significantly lower in the asthmatic than in the control children. There was no significant association between the MCP-1 genotypes and the serum MCP-1 levels.

Thymus and activation regulated chemokine (TARC)/CCL17 and skin diseases

Thymus and activation-regulated chemokine (TARC)/CCL17 is constitutively expressed in the thymus and is produced by dendritic cells (DC), endothelial cells, keratinocytes (KC) and fibroblasts. TARC is designated a Th2 type chemokine since it binds to CCR4. We review the pathogenic role of TARC in skin diseases such as atopic dermatitis (AD), bullous pemphigoid (BP) and mycosis fungoides (MF) focusing on epidermal KC and Langerhans cells (LC), which are epidermal DC. We have determined that serum TARC levels sharply reflect the disease activity of AD, which is thought to be a Th2-dominant inflammatory skin disease especially in the acute phase. Serum TARC levels are also related to the disease activity of BP, which is a blistering autoimmune skin disease, and MF, which is a cutaneous T-cell lymphoma, but very high serum TARC levels are only seen in a limited number of various other skin diseases. TARC may be a useful laboratory marker for the diagnosis of AD, especially cases which are moderate to severe, and for the evaluation of disease activity of AD. IL-4 and TGF-beta1 downregulate TNF-alpha and IFN-gamma induced TARC production in the human KC cell line, HaCaT cells, while IL-4 upregulates, and IFN-gamma downregulates TARC production by mouse LC. Because TARC and its receptor CCR4 are believed to play important roles in the pathogenesis of AD, BP and MF, TARC and CCR4 may be possible future targets for therapy of these diseases.

Both Th1 and Th2 chemokines are elevated in sera of patients with autoimmune blistering diseases

Although chemokines are critical elements for the selective attraction and activation of various leukocyte subsets in the inflammatory process, there are few findings concerning T helper (Th) 1 or Th2 chemokines in autoimmune blistering disease (ABD). To determine whether serum levels of chemokines that are preferentially chemotactic for Th1 (monokine induced by IFN-gamma (MIG/CXCL9)) and Th2 (thymus and activation regulated chemokine (TARC/CCL17) and macrophage derived chemokine (MDC/CCL22)) cells were elevated and whether they correlated with the clinical features in patients with ABD. Serum chemokine levels were examined using ELISA in patients with pemphigus vulgaris (PV, n=19), pemphigus foliaceous (PF, n=14), or bullous pemphigoid (BP, n=27) and normal controls (n=20). Serum MIG levels were significantly higher in patients with PV, PF, or BP than those in the control subjects. Serum levels of TARC and MDC were also significantly elevated in patients with PV, PF, or BP relative to the normal controls. Among the ABD subgroups, the levels of each chemokine tended to be higher in BP patients than in PV patients. Furthermore, serum TARC levels correlated positively with serum IgE levels in patients with ABD. Levels of TARC, MDC, and MIG were significantly decreased after treatment when the skin lesions disappeared in these patients. Furthermore, serum MIG levels correlated positively with serum levels of TARC and MDC in the ABD patients. These results suggest that both a Th1 chemoattractant MIG and Th2 chemoattractants, TARC and MDC, cooperatively play a role in the development of ABD.

Increased Expression of RANTES, CCR3 and CCR5 in the Lesional Skin of Patients with Atopic Eczema

BACKGROUND

Atopic eczema (AE) is a relapsing inflammatory disease based on IgE sensitization and characterized by peripheral blood eosinophilia and eosinophil infiltration into the lesional skin. In the patch test reaction of AE by allergens, an increased infiltration of activated eosinophils has been demonstrated peaking at 24-48 h. Regulated on activation normal T cell expressed and secreted (RANTES/CCL5) is a chemokine that induces eosinophil migration, and CCR3 and CCR5 are the receptors of RANTES.

OBJECTIVE

In order to further clarify the pathomechanisms of eosinophil infiltration in ongoing chronic inflammation in the skin of patients with AE and its relation to disease severity, we examined the expression of RANTES and its receptors CCR3 and CCR5 in challenged and unchallenged lesional skin of AE.

METHODS

We examined the number of RANTES+ cells, CCR3+ cells, CCR5+cells, activated (EG2+) eosinophils and CD3+ T cells in normal skin of healthy volunteers, and in challenged lesional skin (24 h after mite patch test) as well as unchallenged lesional skin of AE patients by immunohistochemistry. The cellular source of RANTES, CCR3 and CCR5 was analyzed by double immunohistochemistry using specific antibodies to RANTES, CCR3 or CCR5, and antibodies to ECP (EG2) or CD3.

RESULTS

The numbers of RANTES+ cells, CCR3+ cells, CCR5+ cells, EG2+ cells and CD3+ cells were all significantly increased in challenged (mite patch-tested) lesional skin of AE patients as compared to those in unchallenged lesional skin and normal skin. The numbers of these cells in unchallenged lesional skin were greater than those in normal skin. The number of EG2+ cells in the unchallenged lesional skin correlated with both the peripheral blood eosinophil count and the SCORAD index. The number of EG2+ cells in challenged lesional skin correlated with the number of CCR5+ cells. Activated eosinophils and T cells expressed RANTES and various proportions of these cells were CCR3+ and CCR5+ in both challenged and unchallenged lesional skin.

CONCLUSION

Taken together, these results suggest that RANTES as well as its receptors CCR3 and CCR5 may play important roles in the orchestration of eosinophil infiltration in ongoing chronic inflammation in AE, and also reflect the severity of disease.

A closer look at chemokines and their role in asthmatic responses

Inflammatory cell recruitment is a hallmark phenomenon of all inflammatory diseases, including allergic asthma. In allergy and asthma, recruitment of inflammatory cells such as T cells, dendritic cells, mast cells, eosinophils and neutrophils, is mediated via a number of chemokines and their receptors. Not only are chemokines involved in recruitment of these cells, they also play a role in activation and differentiation of inflammatory cells, among others, by selectively activating Th1 or Th2 cells or by effects on epithelial or endothelial cells. Binding of chemokines with their receptors has been demonstrated to be highly promiscuous and the subsequent activation pattern on effector cells is very heterogeneous, which has lead to confusion and has complicated research in this field. Nonetheless, chemokines and their receptors are important potential therapeutical targets in allergy and asthma because of their central role in cell recruitment and activation during inflammation.