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Tumors and infectious agents both benefit from an immunosuppressive environment. Cutibacterium acnes ( C. acnes ) is a bacterium in the normal skin microbiota, which has the ability to survive intracellularly in macrophages and is significantly more common in prostate cancer tissue compared with normal prostate tissue. This study investigated if prostate cancer tissue culture positive for C. acnes has a higher infiltration of regulatory T-cells (Tregs) and if macrophages stimulated with C. acnes induced the expression of immunosuppressive genes that could be linked to an increase of Tregs in prostate cancer. Real-time PCR and enzyme-linked immunosorbent spot assay (ELISA) were used to examine the expression of immunosuppressive genes in human macrophages stimulated in vitro with C. acnes , and associations between the presence of C. acnes and infiltration of Tregs were investigated by statistically analyzing data generated in two previous studies. The in vitro results demonstrated that macrophages stimulated with C. acnes significantly increased their expression of PD-L1, CCL17, and CCL18 mRNA and protein ( p < 0.05). In the cohort, Tregs in tumor stroma and tumor epithelia were positively associated with the presence of C. acnes ( P =  0.0004 and P =  0.046, respectively). Since the macrophages stimulated with C. acnes in vitro increased the expression of immunosuppressive genes, and prostate cancer patients with prostatic C. acnes infection had higher infiltration of Tregs than their noninfected counterparts, we suggest that C. acnes may contribute to an immunosuppressive tumor environment that is vital for prostate cancer progression. IMPORTANCE In an immune suppressive tumor microenvironment constituted by immunosuppressive cells and immunosuppressive mediators, tumors may improve their ability to give rise to a clinically relevant cancer. In the present study, we found that C. acnes might contribute to an immunosuppressive environment by recruiting Tregs and by increasing the expression of immunosuppressive mediators such as PD-L1, CCL17, and CCL18. We believe that our data add support to the hypothesis of a contributing role of C. acnes in prostate cancer development. If established that C. acnes stimulates prostate cancer progression it may open up avenues for targeted prostate cancer treatment.

Skullcapflavone II (SFII), a flavonoid derived from Scutellaria baicalensis , has been reported to have anti-inflammatory properties. However, its therapeutic potential for skin inflammatory diseases and its mechanism are unknown. Therefore, this study aimed to investigate the effect of SFII on TNF-α/IFN-γ-induced atopic dermatitis (AD)-associated cytokines, such as thymus- and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC). Co-stimulation with TNF-α/IFN-γ in HaCaT cells is a well-established model for induction of pro-inflammatory cytokines. We treated cells with SFII prior to TNF-α/IFN-γ-stimulation and confirmed that it significantly inhibited TARC and MDC expression at the mRNA and protein levels. Additionally, SFII also inhibited the expression of cathepsin S (CTSS), which is associated with itching in patients with AD. Using specific inhibitors, we demonstrated that STAT1, NF-κB, and p38 MAPK mediate TNF-α/IFN-γ-induced TARC and MDC, as well as CTSS expression. Finally, we confirmed that SFII significantly suppressed TNF-α/IFN-γ-induced phosphorylation of STAT1, NF-κB, and p38 MAPK. Taken together, our study indicates that SFII inhibits TNF-α/IFN-γ-induced TARC, MDC, and CTSS expression by regulating STAT1, NF-κB, and p38 MAPK signaling pathways.

Objectives: GM-CSF is a pro-inflammatory cytokine with multiple actions predominantly on myeloid cells. Enhanced GM-CSF expression by lymphocytes from patients with Ankylosing Spondylitis (AS) has recently been described, however, its potential pathogenic role(s) in AS are unknown. Methods: The effects of GM-CSF on TNF, IL-23, and CCL17 production by blood, PBMCs and isolated CD14+ monocytes from AS patients and healthy controls (HCs) were studied using ELISA. Serum CCL17 and GM-CSF and T cell GM-CSF production were studied in AS patients including pre-and on TNFi therapy. Results: GM-CSF markedly increased TNF production by LPS-stimulated whole blood, peripheral blood mononuclear cells (PBMC) and purified monocytes from AS patients, with 2 h GM-CSF exposure sufficient for monocyte "priming." Blocking of GM-CSF significantly reduced the production of TNF by whole blood from AS patients but not HCs. GM-CSF priming increased IL-23 production from LPS-stimulated AS and HC whole blood 5-fold, with baseline and stimulated IL-23 levels being significantly higher in AS whole blood. GM-CSF also stimulated CCL17 production from AS and HC blood and CCL17 levels were elevated in AS plasma. GM-CSF could be detected in plasma from 14/46 (30%) AS patients compared to 3/18 (17%) HC. Conclusion: We provide evidence that GM-CSF primes TNF and IL-23 responses in myeloid cells from AS patients and HC. We also show CCL17 levels, downstream of GM-CSF, were elevated in plasma samples of AS patients. Taken together these observations are supportive of GM-CSF neutralization as a potential novel therapeutic approach for the treatment of AS., (Copyright © 2020 Shi, Chen, Ridley, Zaarour, Brough, Caucci, Smith and Bowness.)

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphomas associated with chronic inflammation (DLBCL-CI) develop in patients with chronic inflammation but without any predisposing immunodeficiency. Given the expression of the EBV latent genes, DLBCL-CI should have mechanisms for evasion of host antitumor immunity. EBV-positive pyothorax-associated lymphoma (PAL) is a prototype of DLBCL-CI and may provide a valuable model for the study of immune evasion by DLBCL-CI. This study demonstrates that PAL cell lines express and secrete CCL17 and/or CCL22 chemokines, the ligands of C-C motif chemokine receptor 4 (CCR4), in contrast to EBV-negative DLBCL cell lines. Accordingly, culture supernatants of PAL cell lines efficiently attracted CCR4-positive regulatory T (Treg) cells in human peripheral blood mononuclear cells. PAL cells injected into mice also attracted CCR4-expressing Treg cells. Furthermore, this study confirmed that CCR4-expressing Treg cells were abundantly present in primary PAL tissues. Collectively, these findings provide new insight into the mechanisms of immune evasion by PAL, and further studies are warranted on whether such mechanisms eventually lead to the development of DLBCL-CI., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Aim of the Study: In patients with asthma, chronic inflammatory processes and the subsequent remodeling of the airways contribute to the symptoms and the pathophysiological changes. Epithelial-mesenchymal transition (EMT) is thought to play an important role in tissue remodeling. Previous reports show that tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) is a cytokine of the TNF superfamily, exerts pro-inflammatory effects, and enhances transforming growth factor (TGF)-β-induced EMT in bronchial epithelial cells. In this study, we investigated the TWEAK-induced cytokine and chemokine production in the human bronchial epithelial cell line BEAS-2B during EMT., Materials and Methods: Quantitative real-time RT-PCR, enzyme-linked immunosorbent assays, western blotting, and immunohistochemistry were used to define the production of cytokines and chemokines., Results: We found that TWEAK increases mRNA and protein levels of thymic stromal lymphopoietin (TSLP), monocyte chemoattractant protein -1 (MCP-1), regulated upon activation normal T cell express sequence (RANTES), and IL-8 in BEAS-2B bronchial epithelial cells. Moreover, co-treatment with TWEAK and TGF-β1 induces not only features of EMT but also enhances the production of TSLP and RANTES. Thymus- and activation-regulated chemokines (TARC) production is induced by the co-treatment of TWEAK and TGF-β1 but not by TWEAK or TGF-β1 stimulation alone. Furthermore, the increased mRNA expression of TSLP and RANTES after co-treatment with TWEAK and TGF-β1 is prevented by inhibitors of Smad-independent signaling pathways., Conclusions: In the present study, we have revealed a novel mechanism for the production of asthma-related cytokines and chemokines in EMT driven by the co-stimulation with TWEAK and TGF-β1. We conclude that cellular EMT processes caused by TWEAK and TGF-β1 may contribute to chronic airway inflammation and remodeling.

Arachidonate 15-lipoxygenase (ALOX15) and arachidonate 15-lipoxygenase, type B (ALOX15B) catalyze the dioxygenation of polyunsaturated fatty acids and are upregulated in human alternatively activated macrophages (AAMs) induced by Th2 cytokine interleukin-4 (IL-4) and/or interleukin-13. Known primarily for roles in bioactive lipid mediator synthesis, 15-lipoxygenases (15-LOXs) have been implicated in various macrophage functions including efferocytosis and ferroptosis. Using a combination of inhibitors and siRNAs to suppress 15-LOX isoforms, we studied the role of 15-LOXs in cellular cholesterol homeostasis and immune function in naïve and AAMs. Silencing or inhibiting the 15-LOX isoforms impaired sterol regulatory element binding protein (SREBP)-2 signaling by inhibiting SREBP-2 processing into mature transcription factor and reduced SREBP-2 binding to sterol regulatory elements and subsequent target gene expression. Silencing ALOX15B reduced cellular cholesterol and the cholesterol intermediates desmosterol, lanosterol, 24,25-dihydrolanosterol, and lathosterol as well as oxysterols in IL-4-stimulated macrophages. In addition, attenuating both 15-LOX isoforms did not generally affect IL-4 gene expression but rather uniquely impacted IL-4-induced CCL17 production in an SREBP-2-dependent manner resulting in reduced T cell migration to macrophage conditioned media. In conclusion, we identified a novel role for ALOX15B, and to a lesser extent ALOX15, in cholesterol homeostasis and CCL17 production in human macrophages.

Lactobacillus strains, a major group of lactic acid bacteria, are representative food microorganisms that have many potential beneficial effects via their interactions with immune and intestinal epithelial cells. However, little is known about the effect of Lactobacillus strains on atopic dermatitis via keratinocytes, which comprise the physical barrier of the skin. In this study, we report that Lactobacillus strains have a significant suppressive effect on tumour necrosis factor (TNF)-α-induced expression and production of thymus and activation-regulated chemokine (TARC), a T helper 2 cell chemokine responsible for atopic dermatitis, in human keratinocytes. An RNA interference study showed that the effect of Lactobacillus reuteri strain Japan Collection of Microorganisms (JCM) 1112, the most suppressive strain, depended on the presence of Toll-like receptor 2 and the induction of A20 (also known as TNF-α-induced protein 3) and cylindromatosis in HaCaT cells. Topical application of a water-soluble extract of homogenised JCM 1112 cells significantly suppressed the development of house dust mite-induced atopic skin lesions and TARC expression at the lesion sites in NC/Nga mice. Our study provides new insights into the use of Lactobacillus strains as suppressive agents against keratinocyte-involved atopic inflammation of the skin.

Background: Thymus and activation-regulated chemokine (TARC), a member of the CC chemokine family, plays a crucial role in Th2-specific inflammation. We aimed to determine the concentration of sputum TARC in children with asthma and eosinophilic bronchitis (EB) and its relation with eosinophilic inflammation, pulmonary function, and bronchial hyper-responsiveness., Methods: In total, 90 children with asthma, 38 with EB, and 45 control subjects were enrolled. TARC levels were measured in sputum supernatants using an ELISA. We performed pulmonary function tests and measured exhaled fractional nitric oxide, eosinophil counts in blood, and sputum and serum levels of total IgE in all children., Results: Sputum TARC levels were significantly higher in children with asthma than in either children with EB (p=0.004) or the control subjects (p=0.014). Among patients with asthma, sputum TARC concentration was higher in children with sputum eosinophilia than in those without sputum eosinophilia (p=0.035). Sputum TARC levels positively correlated with eosinophil counts in sputum, serum total IgE levels, exhaled fractional nitric, and the bronchodilator response. Negative significant correlations were found between sputum TARC and FEV1/FVC (the ratio of forced expiratory volume in one second and forced expiratory vital capacity) or PC 20 (the provocative concentration of methacholine causing a 20% decrease in the FEV 1 )., Conclusion: Elevated TARC levels in sputum were detected in children with asthma but not in children with EB. Sputum TARC could be a supportive marker for discrimination of asthma from EB in children showing characteristics of eosinophilic airway inflammation., (Copyright © 2017 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.)

Atopic dermatitis (AD) is a chronic inflammatory disease controlled by the innate and adaptive immune system. To elucidate the impact of innate immune signaling in AD, we analyzed MyD88-deficient mice in a murine model of AD-like dermatitis by epicutaneous sensitization with ovalbumin (OVA). Global MyD88 deficiency led to reduced epidermal thickening and diminished accumulation of macrophages within the inflamed skin. In addition, we observed impaired emigration of Langerhans cells (LCs) out of the epidermis of MyD88-deficient mice. These findings indicate that MyD88 deficiency affects various skin-resident cell types in the AD model. Moreover, production of IFN-g, IL-17, and CCL17 was reduced in skin draining lymph node cells and OVA-specific immunoglobulin levels were lower in MyD88-deficient mice. We further investigated the role of MyD88 in keratinocytes, as keratinocytes contribute to AD pathology. Exclusive expression of MyD88 in epidermal keratinocytes partially restored LC emigration after AD induction and expression of CCL17 in skin draining lymph nodes (LNs), but did not promote epidermal thickening nor production of IL-17. Altogether, these data demonstrate that MyD88 signaling in keratinocytes is able to restore LC migration in an otherwise MyD88-deficient background, and significantly contributes to the development of AD-like dermatitis., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Macrophages are dynamic cells that mature under the influence of signals from the local microenvironment into either classically (M1) or alternatively (M2) activated macrophages with specific functional and phenotypic properties. Although the phenotypic identification of M1 and M2 macrophages is well established in mice, this is less clear for human macrophages. In addition, the persistence and reversibility of polarized human phenotypes is not well established. Human peripheral blood monocytes were differentiated into uncommitted macrophages (M0) and then polarized to M1 and M2 phenotypes using LPS/IFN-γ and IL-4/IL-13, respectively. M1 and M2 were identified as CD64(+)CD80(+) and CD11b(+)CD209(+), respectively, by flow cytometry. Polarized M1 cells secreted IP-10, IFN-γ, IL-8, TNF-α, IL-1β, and RANTES, whereas M2 cells secreted IL-13, CCL17, and CCL18. Functionally, M2 cells were highly endocytic. In cytokine-deficient medium, the polarized macrophages reverted back to the M0 state within 12 days. If previously polarized macrophages were given the alternative polarizing stimulus after 6 days of resting in cytokine-deficient medium, a switch in polarization was seen (i.e., M1 macrophages switched to M2 and expressed CD11b(+)CD209(+) and vice versa). In summary, we report phenotypic identification of human M1 and M2 macrophages, their functional characteristics, and their ability to be reprogrammed given the appropriate stimuli.

Gleditsia sinensis thorns have traditionally been used to treat edema and carbuncles and drain abscesses. In the present study, a simultaneous analysis of four flavonoids [(+)‑catechin, (‑)‑epicatechin, eriodictyol and quercetin] and two phenolic compounds (caffeic acid and ethyl gallate), obtained from a 70% ethanol extract of G. sinensis, was performed using high‑performance liquid chromatography‑photodiode array techniques. In addition, the inhibitory activities of the solvent fractions from a G. sinensis extract and its major constituents on the lipopolysaccharide‑stimulated production of inflammatory mediators by macrophage RAW 264.7 cells and the tumor necrosis factor (TNF)‑α and interferon (IFN)‑γ (TI)‑stimulated production of chemokines by HaCaT keratinocyte cells were investigated. The established analytical method showed high linearity, with a correlation coefficient of ≥0.9998. The limits of detection and quantification of the six compounds were 0.037‑0.425 and 0.124‑1.418 µg/ml, respectively. The ethyl acetate fraction inhibited nitric oxide and prostaglandin E2 production in RAW 264.7 cells and the production of thymus‑ and activation‑regulated chemokine (TARC) in HaCaT cells more than did the other fractions. Furthermore, the six compounds reduced the production of TARC, macrophage‑derived chemokine and regulated on activation normal T‑cell expressed and secreted in TI‑stimulated HaCaT cells; in particular, ethyl gallate and quercetin exhibited a significant dose‑dependent inhibition. Further elucidation of the signaling pathways involved in the T‑helper cell 2 chemokine inhibition by G. sinensis is necessary to facilitate the design of therapeutic agents for the inflammatory response.

Mesenchymal stem cells (MSCs) have been investigated in the treatment of numerous autoimmune diseases. However, the immune properties of MSCs on the development of asthma have remained to be fully elucidated. Airway dendritic cells (DCs) have an important role in the pathogenesis of allergic asthma, and disrupting their function may be a novel therapeutic approach. The present study used a mouse model of asthma to demonstrate that transplantation of MSCs suppressed features of asthma by targeting the function of lung myeloid DCs. MSCs suppressed the maturation and migration of lung DCs to the mediastinal lymph nodes, and thereby reducing the allergen-specific T helper type 2 (Th2) response in the nodes. In addition, MSC-treated DCs were less potent in activating naive and effector Th2 cells and the capacity of producing chemokine (C-C motif) ligand 17 (CCL17) and CCL22, which are chemokines attracting Th2 cells, to the airways was reduced. These results supported that MSCs may be used as a potential treatment for asthma.

Basophil-derived IL-4 is involved in the alternative activation of mouse monocytes, as recently shown in vivo. Whether this applies to human basophils and monocytes has not been established yet. Here, we sought to characterise the interaction between basophils and monocytes and identify the molecular determinants. A basophil-monocyte co-culture model revealed that IL-3 and basophil-derived IL-4 and IL-13 induced monocyte production of CCL17, a marker of alternative activation. Critically, IL-3 and IL-4 acted directly on monocytes to induce CCL17 production through histone H3 acetylation, but did not increase the recruitment of STAT5 or STAT6. Although freshly isolated monocytes did not express the IL-3 receptor α chain (CD123), and did not respond to IL-3 (as assessed by STAT5 phosphorylation), the overnight incubation with IL-4 (especially if associated with IL-3) upregulated CD123 expression. IL-3-activated JAK2-STAT5 pathway inhibitors reduced the CCL17 production in response to IL-3 and IL-4, but not to IL-4 alone. Interestingly, monocytes isolated from allergen-sensitised asthmatic patients exhibited a higher expression of CD123. Taken together, our data show that the JAK2-STAT5 pathway modulates both basophil and monocyte effector responses. The coordinated activation of STAT5 and STAT6 may have a major impact on monocyte alternative activation in vitro and in vivo., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Pulmonary fibrosis is a progressive and fatal disease that involves the remodeling of the distal airspace and the lung parenchyma, which results in compromised gas exchange. The median survival time once diagnosed is less than three years. Interleukin (IL)-13 has been shown to play a role in a number of inflammatory and fibrotic diseases. IL-13 modulates its effector functions via a complex receptor system that includes the IL-4 receptor (R) α, IL-13Rα1, and the IL-13Rα2. IL-13Rα1 binds IL-13 with low affinity, yet, when it forms a complex with IL-4α, it binds with much higher affinity, inducing the effector functions of IL-13. IL-13Rα2 binds IL-13 with high affinity but has a short cytoplasmic tail and has been shown to act as a nonsignaling decoy receptor. Transfection of fibroblasts and epithelial cells with IL-13Rα2 inhibited the IL-13 induction of soluble collagen, TGF-β, and CCL17. Adenoviral overexpression of IL-13Rα2 in the lung reduced bleomycin-induced fibrosis. Our work shows that overexpression of IL-13Rα2 inhibits the IL-13 induction of fibrotic markers in vitro and inhibits bleomycin-induced pulmonary fibrosis. In summary our study highlights the antifibrotic nature of IL-13Ra2., (Copyright © 2015 the American Physiological Society.)

Patients with atopic dermatitis (AD) show increased numbers of Th2 cells in their acute skin lesions and superficial skin colonization by Staphylococcus aureus. The purpose of this study was to clarify the effect of S. aureus cell wall components on Th2 chemokine production by murine Langerhans cells (LCs). Murine LCs were stimulated with peptidoglycan (PEG) and/or muramyldipeptide (MDP) for 24 or 48 h, and Th1 and Th2 chemokine production was investigated by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). PEG-stimulation of LCs induced production of the Th2 chemokine CCL17 and this was enhanced in the presence of interleukin (IL)-4. A low-molecular weight PEG fragment, MDP, did not induce CCL17 production by LCs. However, when LCs were stimulated with PEG in combination with MDP, PEG-induced CCL17 production was synergistically enhanced by MDP. Furthermore, PEG- and MDP-induced CCL17 production was enhanced to a greater extent in the presence of IL-4. These results suggest that S. aureus colonization in AD patients may enhance the Th2-prone immune response through upregulation of CCL17 production by LCs, which would occur as a result of simultaneous stimulation with PEG and MDP from S. aureus in a Th2 environment.

Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted special attention as novel nanoprobes capable of improving both the therapy and diagnosis of lung diseases. For safe prospective clinical applications, their biocompatibility has to be assessed after intrapulmonary administration. This study was therefore conducted to understand the biological impact of SPIONs and their further surface-functionalization with polyethylene glycol (PEG) having either negative (i.e. carboxyl) or positive (i.e. amine) terminal in a 1-month longitudinal study following acute and sub-acute exposures. Noninvasive free-breathing MR imaging protocols were first optimized to validate SPIONs detection in the lung and investigate possible subsequent systemic translocation to abdominal organs. Pulmonary Magnetic Resonance Imaging (MRI) allowed successful in vivo detection of SPIONs in the lung using ultra-short echo time sequence. Following high-dose lung administration, MR imaging performed on abdominal organs detected transient accumulation of SPIONs in the liver. Iron quantification using Inductive coupled plasma - Mass mass spectroscopy (ICP-MS) confirmed MRI readouts. Oxidative stress induction and genotoxicity were then conducted to evaluate the biocompatibility of SPIONs with their different formulations in a mouse model. A significant increase in lipid peroxidation was observed in both acute and sub-acute sets and found to regress in a time-dependent manner. PEG functionalized SPIONs revealed a lower effect with no difference between both terminal modifications. Genotoxicity assessments revealed an increase in DNA damage and gene expression of CCL-17 and IL-10 biomarkers following SPIONs administration, which was significantly higher than surface-modified nanoparticles and decreased in a time-dependent manner. However, SPIONs with carboxyl terminal showed a slightly prominent effect compared to amine modification.

Background: Serum levels of thymus and activation-regulated chemokine (TARC/CCL17) have served as a reliable biomarker of disease progression of atopic dermatitis (AD). However, it remains to be scientifically explained why serum TARC levels correlate well with the degree of AD progression., Objective: We hypothesized that dermal cells, but not epidermal keratinocytes, are major cellular sources of TARC and thus responsible for subclinical skin inflammation. This study aimed to identify the skin cells that can produce TARC protein., Methods: Primary normal human epidermal keratinocytes (NHEK), dermal microvascular endothelial cells (HMVEC-dBl) and dermal fibroblasts (NHDF) were stimulated with TNF-α and IL-4, alone and in combination. TARC mRNA and protein levels were quantified by qPCR and ELISA, respectively. We also investigated the effects of such immunosuppressants as a corticosteroid (dexamethasone) and tacrolimus (FK506) on TARC production, and used various signaling inhibitors to evaluate the signaling pathways involved in TARC expression., Results: Although neither TNF-α nor IL-4 alone induced TARC production by any of the tested cell types, together they induced expression of TARC mRNA and appreciable amounts of TARC protein by HMVEC-dBl and NHDF, but not by NHEK. TARC production by those dermal cells was not inhibited by dexamethasone or FK506. TARC production by HMVEC-dBl was completely inhibited by NF-κB and p38 MAPK inhibitors, but not by an ERK inhibitor., Conclusion: Dermal cells, but not epidermal keratinocytes, may be important cellular sources of TARC in AD skin. Therefore, even if epidermal eczematous lesions seem to be improved, complete inhibition of inflammation in the dermis is thought to be particularly important for suppressing both the TARC blood level and progression of AD. However, immunosuppressants did not directly inhibit TARC production by the dermal cells. Anti-inflammatory therapy may decrease TARC blood levels in AD patients indirectly, via its inhibitory effects on TNF-α- and/or IL-4-producing cells in the dermis., (Copyright © 2014 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.)

Mycoplasma pneumoniae causes a range of airway and extrapulmonary pathologies in humans. Clinically, M. pneumoniae is associated with acute exacerbations of human asthma and a worsening of experimentally induced asthma in mice. Recently, we demonstrated that Community Acquired Respiratory Distress Syndrome (CARDS) toxin, an ADP-ribosylating and vacuolating toxin synthesized by M. pneumoniae, is sufficient to induce an asthma-like disease in BALB/cJ mice. To test the potential of CARDS toxin to exacerbate preexisting asthma, we examined inflammatory responses to recombinant CARDS toxin in an ovalbumin (OVA) murine model of asthma. Differences in pulmonary inflammatory responses between treatment groups were analyzed by histology, cell differentials and changes in cytokine and chemokine concentrations. Additionally, assessments of airway hyperreactivity were evaluated through direct pulmonary function measurements. Analysis of histology revealed exaggerated cellular inflammation with a strong eosinophilic component in the CARDS toxin-treated group. Heightened T-helper type-2 inflammatory responses were evidenced by increased expression of IL-4, IL-13, CCL17 and CCL22 corresponding with increased airway hyperreactivity in the CARDS toxin-treated mice. These data demonstrate that CARDS toxin can be a causal factor in the worsening of experimental allergic asthma, highlighting the potential importance of CARDS toxin in the etiology and exacerbation of human asthma.

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., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Ribavirin has proven to be a key component of hepatitis C therapies both involving IFNs and new direct-acting antivirals. The hepatitis C virus-mediated interference with intrahepatic immunity by cleavage of mitochondrial antiviral signaling protein (MAVS) and T cell protein tyrosine phosphatase (TCPTP) suggests an avenue for compounds that may counteract these effects. We therefore studied the effects of ribavirin, with or without inhibition of the nonstructural (NS)3/4A protease, on intrahepatic immunity. The intrahepatic immunity of wild-type and NS3/4A-transgenic mice was determined by Western blot, ELISA, flow cytometry, and survival analysis. Various MAVS or TCPTP constructs were injected hydrodynamically to study their relevance. Ribavirin pretreatment was performed in mice expressing a functional or inhibited NS3/4A protease to analyze its effect on NS3/4A-mediated changes. Intrahepatic NS3/4A expression made mice resistant to TNF-α-induced liver damage and caused an alteration of the intrahepatic cytokine (IFN-γ and IL-10) and chemokine (CCL3, CCL17, CCL22, CXCL9, and CXCL11) profiles toward an anti-inflammatory state. Consistent with this, the number of intrahepatic Th1 cells and IFN-γ(+) T cells in NS3/4A-transgenic mice decreased, whereas the amount of Th2 cells increased. These effects could be reversed by injection of uncleavable TCPTP but not uncleavable MAVS and were absent in a mouse expressing a nonfunctional NS3/4A protease. Importantly, the NS3/4A-mediated effects were reversed by ribavirin treatment. Thus, cleavage of TCPTP by NS3/4A induces a shift of the intrahepatic immune response toward a nonantiviral Th2-dominated immunity. These effects are reversed by ribavirin, supporting that ribavirin complements the effects of direct-acting antivirals as an immunomodulatory compound.

A phytosterol derivative, 3-O-β-D-glucopyanosylspinasterol (spinasterol-Glc) isolated from leaves of Stewartia koreana was reported to inhibit LPS-induced cytokine production in macrophage cells. Thymus and activation regulated chemokine (TARC/CCL17) is produced in response to pro-inflammatory cytokines in keratinocytes, which is implicated in the development of inflammatory skin diseases. In present study, we investigated the effect of spinasterol-Glc on production of TARC/CCL17 induced by TNF-α and IFN-γ in human HaCaT keratinocytes. Spinasterol-Glc inhibited the mRNA and protein expression of TARC/CCL17 induced by TNF-α/IFN-γ in a dose-dependent manner. Inhibitors of c-Raf-1, p38 MAPK, and JAK2, suppressed the TNF-α/IFN-γ-induced production of TARC/CCL17, and phosphorylation of these signaling molecules were attenuated by spinasterol-Glc. The compound also inhibited phosphorylation of IKKα/β and IκB-α, and reduced translocation of NF-κB to the nucleus. We demonstrated that spinasterol-Glc suppressed the NF-κB-driven and the GAS-driven expression of luciferase reporter gene induced by TNF-α and IFN-γ. In addition, spinasterol-Glc inhibited the DNA binding of NF-κB and STAT1 to its cognate binding site. These results suggest that spinasterol-Glc has effective inhibitory effects on production of TARC/CCL17 in keratinocytes via inhibition of NF-κB as well as STAT activation, and could be utilized for development of a potential therapeutic agent against skin inflammatory diseases., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Although histamine H1 receptor (H1R) antagonists are commonly used to treat atopic dermatitis, the treatment is not always effective. The histamine H4 receptor (H4R) was recently described as important to the pruritus in dermatitis. Here, we investigated whether the combination of a H1R antagonist plus a H4R antagonist attenuates chronic dermatitis in NC/Nga mice., Methods: Chronic dermatitis was developed by repeated challenges with picryl chloride on the dorsal back and ear lobes. The therapeutic effects of the H1R antagonist olopatadine and H4R antagonist JNJ7777120 on scratching and the severity of dermatitis were evaluated. In addition, the mechanisms responsible for the anti-allergic effects of H1R and/or H4R antagonism were examined using bone marrow-derived mast cells (BMMC) and keratinocytes., Results: JNJ7777120 attenuated scratching behavior after a single administration and improved dermatitis, as assessed with clinical scores, pathology, and cytokine levels in skin lesions when administered repeatedly. These effects were augmented by combined treatment with olopatadine, having a similar therapeutic efficacy to prednisolone. JNJ7777120 inhibited dose-dependently the production of thymus and activation-regulated chemokine/CCL17 and macrophage-derived chemokine/CCL22 from antigen-stimulated BMMC. In addition, olopatadine reversed the histamine-induced reduction of semaphorin 3A mRNA in keratinocytes., Conclusion: Combined treatment with H1R and H4R antagonists may have a significant therapeutic effect on chronic dermatitis through the synergistic inhibition of pruritus and skin inflammation., (© 2012 John Wiley & Sons A/S.)

Tacrolimus (FK-506) has been found to exhibit potent inhibitory effects on spontaneously developed dermatitis. We previously showed that glucosamine prevents the development of Atopic dermatitis (AD)-like skin lesions in NC/Nga mice. The aims of our study were to investigate the synergistic therapeutic efficacy of combination of glucosamine plus FK-506 in dermatophagoides farina (Df)-induced AD-like skin lesions in NC/Nga mice and to determine the underlying therapeutic mechanisms. The Df-induced NC/Nga mice with a clinical score of 8 were used for treatment with glucosamine (500 mg/kg) alone, FK-506 (1.0 mg/kg) or in combination. The synergistic effects of combination therapy were evaluated by dermatitis scores, skin histology and immunological parameters such as IgE, Th2-mediated cytokines and chemokines, CD3(+) T cells and CLA(+) T cells. Combined therapy using glucosamine plus FK-506 improved the development of AD-like skin lesions as exemplified by a significant decrease in total skin symptom severity scores. The suppression of dermatitis by combined therapy was accompanied by a decrease in the plasma level of IgE and in the splenic level of IL-5, IL-13, TARC and eotaxin. Histological finding indicated that the dermal infiltration of inflammatory cells including mast cells and eosinophils was greatly reduced. Particularly, immunohistological evaluation reveals a reduction in CD3(+) T cells and CLA(+) cells in the combined therapy. Our findings suggest that combination therapy of glucosamine plus FK-506 was more synergistic efficacy than single-modality treatment with either alone to improve the development of established dermatitis in NC/Nga mice model. This combined immunosuppressive therapy may provide an effective therapeutic strategy for the treatment of AD., (© 2011 The Authors. Scandinavian Journal of Immunology © 2011 Blackwell Publishing Ltd.)

Casuarinin is a naturally occurring tannin that is isolated from the leaves of Hippophae rhamnoides. It has been shown to have anti-oxidant, anti-cancer, anti-viral, and anti-inflammatory activities. The aim of this study was to investigate the possible mechanism by which casuarinin inhibits TNF-α/IFN-γ-induced Th2 chemokines expression in the human keratinocytes cell line HaCaT. We found that casuarinin suppressed TNF-α/IFN-γ-induced expression of TARC and MDC mRNA and protein in HaCaT cells. Casuarinin significantly inhibited TNF-α/IFN-γ-induced activation of NF-κB, STAT1, and p38 MAPK. Furthermore, we observed that p38 MAPK contributes to inhibition of TNF-α/IFN-γ-induced TARC and MDC production by blocking NF-κB and STAT1 activation in HaCaT cells. Taken together, these results suggest that casuarinin may exert anti-inflammatory responses by suppressing TNF-α/IFN-γ-induced expression of TARC and MDC via blockage of p38 MAPK activation and subsequent activation of NF-κB and STAT1. We propose that it could therefore be used as a therapeutic agent against inflammatory skin diseases., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective: Utilizing a food allergy murine model, we have investigated the intrinsic antiallergic potential of the Lactococcus lactis NCC 2287 strain., Methods: BALB/c mice were sensitized at weekly intervals with ovalbumin (OVA) plus cholera toxin (CT) by the oral route for 7 weeks. In this model, an oral challenge with a high dose of OVA at the end of the sensitization period leads to clinical symptoms. Lactococcus lactis NCC 2287 was given to mice via the drinking water during sensitization (prevention phase) or after sensitization (management phase)., Results: Lactococcus lactis NCC 2287 administration to sensitized mice strikingly reduced allergic manifestations in the management phase upon challenge, when compared to control mice. No preventive effect was observed with the strain. Lactococcus lactis NCC 2287 significantly decreased relative expression levels of the Th-2 cytokine, IL-13, and associated chemokines CCL11 (eotaxin-1) and CCL17 (TARC) in the ileum. No effect was observed in the jejunum., Conclusion/significance: These results taken together designate Lactococcus lactis NCC 2287 as a candidate probiotic strain appropriate in the management of allergic symptoms.

Alloreactive T cells that infiltrate the graft after lung transplantation (LTx) play a role in chronic rejection. Chemokines such as thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC) and monocyte chemotactic protein-1 (MCP-1) are produced locally in the lung and attract T cells via chemokine receptor 4 (CCR4). In a TARC gradient, cells expressing CCR4(++) migrate more efficiently than CCR4(+) -expressing cells. In this study, we compared the CCR4 expression of T cells in blood from 20 lung transplant recipients to healthy controls. We then examined whether CCR4 expression is associated with the occurrence of chronic rejection. The CCR4(++) expression was decreased on CD4 T cells from LTx patients (P < 0·0001) when compared to healthy controls. The analysis of CD4 T cell subsets showed that this decrease was present on central memory, effector memory and terminally differentiated T cells (P = 0·0007, P < 0·0001 and P = 0·05, respectively), while a trend was found for naive CD4 T cells (P = 0·06). Also, the expression of CCR4(+) on regulatory T cells (T(regs) ) was decreased in LTx patients when compared to healthy controls (P = 0·02). Interestingly, the CCR4(++) expression on CD4 effector memory T cells was decreased in patients developing chronic rejection sometimes more than a year before the clinical diagnosis when compared to patients who did not (P = 0·04). The analysis of CD8 T cell subsets only showed the CCR4(+) expression to be increased significantly on effector memory and terminally differentiated CD8 T cells (P = 0·02, P = 0·03, respectively) in LTx patients, but no relation was found in chronic rejection. In conclusion, the expression of CCR4 on T cell subsets was altered after LTx and appears to be related to chronic rejection., (© 2011 The Authors. Clinical and Experimental Immunology © 2011 British Society for Immunology.)

Background & Aims: The mechanisms by which Foxp3+ T regulatory cells (Treg) accumulate in HCV infected livers are not known. Here, we studied the role of chemokines CCL17 and CCL22 in this process., Methods: Chemokine mRNA levels were determined by qPCR in liver biopsies from 26 HCV chronically infected patients (CHC), 11 patients with treatment-induced sustained virological response (SVR), 16 patients with other liver diseases unrelated to HCV, and 24 normal livers. Double-immunofluorescence Foxp3/CD3 or CD11c/CCL22 was performed in liver sections. Chemokine production by monocyte-derived dendritic cells (MDDC) co-cultured with uninfected or HCV-JFH1 infected Huh7 cells was measured by qPCR and ELISA. Chemotactic activity of culture supernatants was also tested., Results: Foxp3+ Treg were increased in CHC livers as compared to controls. Patients with CHC showed elevated intrahepatic levels of CCL17 mRNA compared to normal livers or livers from subjects with SVR or other forms of liver disease. Intrahepatic CCL22 expression was also higher in CHC than in healthy subjects or SVR patients but similar to that observed in other liver diseases. Dendritic cells producing CCL22 could be found inside the hepatic lobule in CHC patients. Contact between MDDC and HCV-JFH1-infected Huh7 cells induced the expression of CCL17 and CCL22 in a process partially dependent on ICAM-1. Transwell experiments showed that upregulation of these chemokines enhanced Treg migration., Conclusions: Contact of HCV-infected cells with dendritic cells induces the production of Treg-attracting chemokines, an effect which may favour liver accumulation of Treg in CHC. Our findings contribute to explain the mechanism by which HCV escapes the immune response and thus reveals novel therapeutic targets., (Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Microbial products, including lipopolysaccharide, may be involved in the pathogenesis of skin diseases such as atopic dermatitis. Diarylheptanoids such as oregonin and hirsutenone have been shown to have an anti-inflammatory effect. We investigated the effect of hirsutenone on lipopolysaccharide-induced inflammatory mediator production in keratinocytes in relation to the Toll-like receptor 4-mediated activation of the extracellular signal-regulated kinase (ERK) and nuclear factor (NF)-kappaB pathways. Hirsutenone, dexamethasone, ERK inhibitor or Bay 11-7085 (an inhibitor of NF-kappaB activation) reduced the lipopolysaccharide-induced production of cytokines IL-1beta and IL-8, and the chemokine CCL17. Hirsutenone, ERK inhibitor or Bay 11-7085 also prevented the lipopolysaccharide-induced expression of Toll-like receptor 4, the phosphorylation of inhibitory kappaB-alpha, the activation of NF-kappaB and the expression of ERK. The results show that hirsutenone may reduce the lipopolysaccharide-stimulated production of inflammatory mediators in keratinocytes by suppressing the Toll-like receptor 4 expression-mediated NF-kappaB activation that is regulated by the ERK pathway. These findings suggest that hirsutenone may exert a preventive effect against microbial endotoxin lipopolysaccharide-induced inflammatory skin diseases through inhibition of ERK pathway-mediated NF-kappaB activation., (Copyright 2010 Elsevier B.V. All rights reserved.)

There is increasing evidence that titanium (Ti(IV)) ions are released from orthopedic implants and play a role in aseptic loosening. This study aimed to investigate whether titanium induces expression of chemokines and cytokines that are important in osteoclastogenesis in human osteoclasts and osteoblasts. Incubation of those cells with 1 muM Ti(IV) significantly upregulated expression of CCL17/TARC and CCL22/MDC, RANK-L, M-CSF and pro-inflammatory cytokines as determined by quantitative real-time PCR and ELISA assays. Additionally, flow cytometry was used to show Ti(IV) related increased expression of CCR4, the cognate receptor for CCL17 and CCL22 in challenged osteoclast precursors. These results strongly suggest that Ti(IV) ions play a role in the recruitment of osteoclast precursors to the bone-implant interface by increasing CCL17 and CCL22 expression and by upregulating their cognate receptor. Moreover the increased expression of RANK-L and M-CSF by osteoblasts together with increased levels of pro-inflammatory cytokines may enhance osteoclast differentiation and activity, and subsequently contribute to the pathomechanism of aseptic loosening., ((c) 2009 Wiley Periodicals, Inc.)

Background: Schefflera leucantha Viguier is used as a traditional medicine in Thailand and China to relieve chronic cough and asthma. However, little is known about its anti-allergic effects., Objective: This study was designed to investigate the effects of S leucantha ethanol extract (SLEE) on chemokine production by epidermal Langerhans cells (LCs) stimulated with peptidoglycan (PEG) from Staphylococcus aureus and histamine release from mast cells., Methods: LCs were purified from murine epidermal cells using the panning method with anti-IA(d) monoclonal antibody. Chemokine production by LCs was investigated by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). Mast cells for histamine release assay were induced by long-term culture of mouse spleen cells. Histamine release from these mast cells was measured by a competitive ELISA., Results: Production of the eosinophil chemoattractant CCL5 and the type 2 T helper (TH2)-associated chemokine CCL17 from PEG-stimulated LCs was significantly inhibited by SLEE. Furthermore, SLEE significantly decreased the release of histamine from mast cells by IgE-mediated degranulation., Conclusion: These results suggest that S leucantha may offer a new therapeutic approach for the control of atopic dermatitis associated with S aureus colonization through inhibition of the production of allergic mediators.

Keratinocytes, one of major cell types in the skin, can be induced by TNF-alpha and IFN-gamma to express thymus- and activation-regulated chemokine (TARC/CCL17), which is considered to be a pivotal mediator in the inflammatory responses during the development of inflammatory skin diseases, such as atopic dermatitis (AD). In this study, we examined the effect of 1,2,3,4,6-penta-O-galloyl-beta-d-glucose (PGG), isolated from the barks of Juglans mandshurica, on TNF-alpha/IFN-gamma induced CCL17 expression in the human keratinocyte cell line HaCaT. Pretreatment of HaCaT cells with PGG suppressed TNF-alpha/IFN-gamma-induced protein and mRNA expression of CCL17. PGG significantly inhibited TNF-alpha/IFN-gamma-induced NF-kappaB activation as well as STAT1 activation. Furthermore, pretreatment with PGG resulted in significant reduction in expression of CXCL9, 10, and 11 in the HaCaT cells treated with IFN-gamma. These results suggest that PGG may exert anti-inflammatory responses by suppressing TNF-alpha and/or IFN-gamma-induced activation of NF-kappaB and STAT1 in the keratinocytes and might be a useful tool in therapy of skin inflammatory diseases.

Introduction: Changes in the levels of serum cytokines and growth factors are associated with response to therapy. We examined cytokine, chemokine, and growth factor levels in serum collected from normal volunteers or metastatic melanoma patients receiving dendritic cell-based immunotherapy., Materials and Methods: Using an array for 42 cytokines, chemokines, or growth factors, sera from normal controls and metastatic melanoma patients at baseline and week 4 were analyzed for qualitative changes. Quantitative determination of the levels of the chemokine thymus and activation-regulated chemokine (TARC/CCL17) was determined by enzyme-linked immunosorbent assay (ELISA)., Results: Significant qualitative differences were noted in serum cytokine, chemokine, and growth factor levels of metastatic melanoma patients versus the normal controls at baseline. The results also demonstrated a significant decrease in the level of angiogenin (P = 0.026) and a significant increase in TARC/CCLl7 (P = 0.008) from week 0 to week 4 which was associated with improved overall survival (P = 0.059). Higher TARC/CCL17 levels were observed by ELISA at week 4 and a log-rank comparison revealed a significant association between high serum TARC/CCL17 levels at week 4 and progression-free survival (P = 0.005). Receiver-operator characteristic analysis revealed that week 4 serum TARC/CCL17 levels were predictive of progression-free and overall survival, indicating that serum TARC/CCL17 might be of predictive value of response to dendritic cell-based anti-melanoma immunotherapy.

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.

In human trials, Bifidobacterium longum BB536 alleviates subjective symptoms of Japanese cedar pollinosis, an IgE-mediated type I allergy caused by exposure to Japanese cedar, and significantly suppresses the increase of plasma thymus- and activation-regulated chemokine (TARC) associated with pollen dispersion. In the present study, we investigated the suppressive effects of BB536 on the production of T helper type 2 (Th2)-attracting chemokines, such as TARC and macrophage-derived chemokine (MDC), together with the mechanisms of their production. Murine splenocytes were cultured with heat-killed BB536, and the levels of Th2-attracting chemokines in the supernatants were measured. TARC and MDC were produced in cultures without stimulation, and the production was significantly suppressed by BB536. These chemokines were produced by antigen-presenting cells (APCs) of splenocytes stimulated with an anti-CD40 antibody. Furthermore, TARC production was induced with granulocyte macrophage colony-stimulating factor that was produced by T cells and dendritic cells. BB536 suppressed MDC production induced with the anti-CD40 antibody by APCs from the spleen, mesenteric lymph nodes (MLNs) and Peyer's patches, and it suppressed TARC production by APCs from the spleen and MLNs. These results indicate that BB536 suppresses the production of Th2-attracting chemokines induced by the T cell-APC interaction, suggesting a novel mechanism for alleviating symptoms of allergic disorders by probiotics.

STAT6-mediated chemokine production in the lung is required for Th2 lymphocyte and eosinophil homing into the airways in allergic pulmonary inflammation, and thus is a potential therapeutic target in asthma. However, the critical cellular source of STAT6-mediated chemokine production has not been defined. In this study, we demonstrate that STAT6 in bone marrow-derived myeloid cells was sufficient for the production of CCL17, CCL22, CCL11, and CCL24 and for Th2 lymphocyte and eosinophil recruitment into the allergic airway. In contrast, STAT6 in airway-lining cells did not mediate chemokine production or support cellular recruitment. Selective depletion of CD11b(+) myeloid cells in the lung identified these cells as the critical cellular source for the chemokines CCL17 and CCL22. These data reveal that CD11b(+) myeloid cells in the lung help orchestrate the adaptive immune response in asthma, in part, through the production of STAT6-inducible chemokines and the recruitment of Th2 lymphocytes into the airway.

IL-12 family members are an important link between innate and adaptive immunity. IL-12 drives Th1 responses by augmenting IFN-gamma production, which is key for clearance of intracellular pathogens. IL-23 promotes the development of IL-17-producing CD4(+) T cells that participate in the control of extracellular pathogens and the induction of autoimmunity. However, recent studies have shown that these cytokines can modulate lymphocyte migration and cellular interactions. Therefore, we sought to determine the individual roles of IL-12 and IL-23 in naive CD8(+) T cell activation by addressing their ability to influence IFN-gamma production and cellular interaction dynamics during priming by Listeria monocytogenes-infected dendritic cells (DC). We found that IL-12 was the major cytokine influencing the level of IFN-gamma production by CD8(+) T cells while IL-23 had little effect on this response. In addition, we observed that IL-12 promoted longer duration conjugation events between CD8(+) T cells and DC. This enhanced cognate interaction time correlated with increased production of the chemokines CCL1 and CCL17 by WT but not IL-12-deficient DC. Neutralization of both chemokines resulted in reduced interaction time and IFN-gamma production, demonstrating their importance in priming naive CD8(+) T cells. Our study demonstrates a novel mechanism through which IL-12 augments naive CD8(+) T cell activation by facilitating chemokine production, thus promoting more stable cognate interactions during priming.

Background: Antihistamines are widely used for the treatment of allergic diseases, such as urticaria and allergic rhinitis. They are also effective for the treatment of diseases in which T cells are mainly involved in the pathogenesis, such as atopic dermatitis (AD) and contact dermatitis. Dendritic cells (DCs) drive polarization of naive T cells into Th1 or Th2 subsets, and are also likely to be involved in AD pathogenesis., Objectives: The aim of this study was to determine the effects of antihistamines on DCs and CD4+ T cells., Methods: Human monocyte-derived DCs (MoDCs) and autologous CD4+ T cells were obtained from healthy subjects, and cultured together or independently in the presence of antihistamines. As a stimulant, we used staphylococcal enterotoxin B or the combination of anti-CD3 monoclonal antibody (mAb) and anti-CD28 mAb. The concentrations of cytokines and chemokines in culture supernatants were measured by ELISA. The expression of surface molecules on MoDCs was measured by flow cytometry. Cell proliferation in the cocultures of MoDCs and CD4+ T cells (DC-T cocultures) was measured by a [(3)H] thymidine incorporation assay., Results: Antihistamines inhibited the production of IFN-gamma, and enhanced the production of IL-4 in DC-T cocultures. Antihistamines inhibited the production of TNF-alpha, TARC, MDC, IP-10, and Mig from MoDCs. Epinastine, one of antihistamines, suppressed the expression of ICAM-1 (CD54) on MoDCs. Epinastine also inhibited the proliferation of CD4+ T cells cocultured with MoDCs., Conclusions: Our findings show that antihistamines regulate immune responses by affecting the interaction between DCs and CD4+ T cells, and further DCs and CD4+ T cells independently, which may partially contribute to the control of allergic diseases such as AD and contact dermatitis.

Asthma and chronic obstructive pulmonary disease (COPD) are associated with Th2 and Th1 differentiated T cells. The cytokine thymic stromal lymphopoietin (TSLP) promotes differentiation of Th2 T cells and secretion of chemokines which preferentially attract them. We hypothesized that there is distinct airways expression of TSLP and chemokines which preferentially attract Th1- and Th2-type T cells, and influx of T cells bearing their receptors in asthma and COPD. In situ hybridization, immunohistochemistry, and ELISA were used to examine the expression and cellular provenance of TSLP, Th2-attracting (TARC/CCL17, MDC/CCL22, I-309/CCL1), and Th1-attracting (IP-10/CXCL10, I-TAC/CXCL11) chemokines in the bronchial mucosa and bronchoalveolar lavage fluid of subjects with moderate/severe asthma, COPD, and controls. Cells expressing mRNA encoding TSLP, TARC/CCL17, MDC/CCL22, and IP-10/CXCL10, but not I-TAC/CXCL11 and I-309/CCL1, were significantly increased in severe asthma and COPD as compared with non-smoker controls (p < 0.02). This pattern was reflected in bronchoalveolar lavage fluid protein concentrations. Expression of the same chemokines was also increased in ex- and current smokers. The cellular sources of TSLP and chemokines were strikingly similar in severe asthma and COPD. The numbers of total bronchial mucosal T cells expressing the chemokine receptors CCR4, CCR8, and CXCR3 did not significantly differ in asthma, COPD, and controls. Both asthma and COPD are associated with elevated bronchial mucosal expression of TSLP and the same Th1- and Th2-attracting chemokines. Increased expression of these chemokines is not, however, associated with selective accumulation of T cells bearing their receptors.

Epigenetic changes have been implicated in silencing several B-cell genes in Hodgkin and Reed-Sternberg cells (HRS) of Hodgkin lymphoma (HL), and this mechanism has been proposed to promote HRS survival and escape from immunosurveillance. However, the molecular and functional consequences of histone deacetylase (HDAC) inhibition in HL have not been previously described. In this study, we report that the HDAC inhibitor vorinostat induced p21 expression and decreased Bcl-xL levels causing cell-cycle arrest and apoptosis. Furthermore, vorinostat inhibited STAT6 phosphorylation and decreased its mRNA levels in a dose- and time-dependent manner, which was associated with a decrease in the expression and secretion of Thymus and Activation-Regulated Chemokine (TARC/CCL17) and interleukin (IL)-5 and an increase in IP-10 levels. Moreover, vorino-stat inhibited TARC secretion by dendritic cells that were activated by the thymic stromal lymphopoietin (TSLP). Collectively, these data suggest that pharmacologic HDAC inhibition in HL may induce favorable antitumor activity by a direct antiproliferative effect on HRS cells, and possibly by an immune mediated effect by altering cytokine and chemokines secretion in the microenvironment.

Thymus and activation-regulated chemokine (TARC) is one that selectively controls the migration of type 2-helper T lymphocytes into inflammatory lesions. TARC is a CC chemokine, and plays an essential role in recruiting CC chemokine receptor 4-positive Th2 cells to allergic lesions. We cloned TARC cDNA from rat thymus using RT-PCR. The rat TARC clone contained a full-length open reading frame encoding 93 amino acids that showed 83% and 66% homology with mouse and human homologs, respectively. The expression of TARC mRNA was mainly in the lymphoid organs, for example, the thymus, spleen, and lymph node. The recombinant TARC was expressed in Escherichia coli and purified in an active form. In addition, the purified rat TARC with S-tagged specifically binds to human CCR4 in CD4.CCR4-transfected HOS cells by Cell-binding assay using flow-cytometry. The TARC cDNA clones obtained in this study will be valuable for future studies on allergic diseases in rats.

Condylomata acuminata derived from the infection of human papillomavirus is a common sexually transmitted disease. Although T cell-mediated cellular immunity is considered as the main arm against such infection, the regulation of T cell immune responses in genital condylomata is unclear to date. In this study, we analyzed FOXP3(+) regulatory T cells in genital condylomata of patients. The results show that FOXP3(+) regulatory T cells with suppressive function accumulated in large warts. Consistently, the immunosuppressive milieu in large warts was characterized by high expression of IL-10 and TGF-beta1 and low expression of IL-2 and IFN-gamma. The responsiveness of wart-infiltrating T cells both in vitro and in vivo can be increased by depleting FOXP3(+) T cells. The accumulation of FOXP3(+) regulatory T cells in large warts can be partly ascribed to the chemotaxis of CCL17 and CCL22, derived from Langerhans cells and macrophages in wart. Although such accumulation favors the local immunosuppression, it seems not to influence the systemic immunity. In conclusion, these findings demonstrate that FOXP3(+) regulatory T cells play an important role in genital condylomata, which has multiple implications in the comprehensive treatment of condylomata acuminata.

Objective: To examine the effects of cytokines and poly IC on the expression of thymus- and activation-regulated chemokine (TARC), a potent chemoattractant for helper T-cell type 2 (T(H)2) cells, in nasal polyp fibroblasts., Design: Quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis., Setting: Academic research., Participants: Primary fibroblast lines were established from human nasal polyp biopsy tissue specimens (n = 5) removed at polypectomy., Main Outcome Measures: The expression of TARC messenger RNA (mRNA) was evaluated by real-time RT-PCR. The amount of TARC in the supernatants was measured by enzyme-linked immunosorbent assay., Results: Combined stimulation with interleukin 4 (IL-4) and tumor necrosis factor alpha (TNF-alpha) or with poly IC and IL-4 induced TARC production. Combined exposure of cells to poly IC, IL-4, and TNF-alpha resulted in substantial amounts of TARC release into the culture medium. Quantitative RT-PCR analysis revealed that simultaneous stimulation with those 3 compounds induced a tremendous increase in the amount of TARC mRNA in the nasal polyp fibroblasts., Conclusion: Nasal polyp fibroblasts contribute to T(H)2 cell infiltration and RNA virus-induced exacerbation of T(H)2-type airway inflammatory conditions such as allergic chronic sinusitis.

Background: Surfactant protein (SP) D has been proposed to be protective in allergic airway responses., Objective: We aimed to determine the effect of SP-D deficiency on murine and human airway allergy., Methods: Immunologic responses of SP-D gene-deficient mice (Sftpd-/-) at baseline and after 4 intranasal Aspergillus fumigatus exposures were assessed. In addition, the significance of a single nucleotide polymorphism (Met(11)Thr) in the human SP-D gene (known to decrease SP-D function) was investigated., Results: Macrophage and neutrophil bronchoalveolar lavage fluid levels and large airway mucus production were increased in naive Sftpd-/- mice in association with increased lung CCL17 levels and CD4+ T cell numbers. T(H)2-associated antibody levels (IgG1 and IgE) were significantly lower in 4- to 5-week-old Sftpd-/- mice (P < .05). Accordingly, naive Sftpd-/- splenocytes released significantly less IL-4 and IL-13 on anti-CD3/CD28 stimulation (P < .01). After intranasal allergen exposures, a modest decrease in bronchoalveolar lavage fluid eosinophilia and IL-13 levels was observed in Sftpd-/- mice compared with values seen in wild-type mice in association with decreased airway resistance (P < .01). A single nucleotide polymorphism in the SFTPD gene, affecting SP-D levels and pathogen binding, was associated with decreased atopy in black subjects and potentially lower asthma susceptibility in white subjects., Conclusion: Sftpd-/- mice have an impaired systemic T(H)2 response at baseline and reduced inflammation and airway responses after allergen exposure. Translational studies revealed that a polymorphism in the SFTPD gene was associated with lower atopy and possibly asthma susceptibility. Taken together, these results support the hypothesis that SP-D-dependent innate immunity influences atopy and asthma.

Ethnopharmacological Relevance: Houttuynia cordata Thunb (Saururaceae), known as 'E-Sung-Cho' in Korea, has been traditionally used for the treatment of herpes simplex, chronic sinusitis, and allergy., Aim of the Study: To investigate the inhibitory activity of Houttuynia cordata Thunb fractions (HcFs) on the T helper 2 (Th2) immune response, we evaluated the alternation of the release of Th2-type cytokines and chemokines such as interleukin (IL)-4 and IL-5, and thymus and activation-regulated chemokine (TARC/CCL17)., Materials and Methods: Ethanol fraction was obtained from dried and powdered whole plants of Houttuynia cordata Thunb using ethanol. The residue was diluted with water and was then successively partitioned with n-hexane, EtOAc and BuOH. HcFs include ethanol, n-hexane, EtOAc, BuOH and water fractions. RT-PCR and ELISA were performed to measure mRNA and protein expression of cytokines., Results: HcFs inhibited the expression of IL-4 and IL-5 in response to phorbol 12-myristate 13-acetate (PMA) and calcium ionophore (CaI) in Jurkat T cells and the human mast cell line, HMC-1. IL-4- and tumor necrosis factor-alpha (TNF-alpha)-induced TARC production was blocked by HcFs in skin fibroblast CCD-986sk cells, particularly by the ethanol extract of Hc. Stimulants included in PMA, phytohemagglutinin (PHA) and CaI, increased the mRNA level of CC chemokine receptor 4 (CCR4), a receptor of TARC, in Jurkat T cells, and the ethanol extract of HcF weakly blocked the increased mRNA level. However, the stimulants and ethanol extract had no effect on the CCR4 protein level. The ethanol extract inhibited TARC-induced migration, as well as basal migration of Jurkat T cells., Conclusions: This study may show the usefulness of HcFs in the ethnopharmacological treatment of Th2-mediated or allergic inflammation, through the down-regulation of the production of Th2 cytokines and TARC, as well as cell migration.

The current paradigm surrounding allergen-mediated T helper type 2 (Th2) immune responses in the lung suggests an almost hegemonic role for T cells. Our studies propose an alternative hypothesis implicating eosinophils in the regulation of pulmonary T cell responses. In particular, ovalbumin (OVA)-sensitized/challenged mice devoid of eosinophils (the transgenic line PHIL) have reduced airway levels of Th2 cytokines relative to the OVA-treated wild type that correlated with a reduced ability to recruit effector T cells to the lung. Adoptive transfer of Th2-polarized OVA-specific transgenic T cells (OT-II) alone into OVA-challenged PHIL recipient mice failed to restore Th2 cytokines, airway histopathologies, and, most importantly, the recruitment of pulmonary effector T cells. In contrast, the combined transfer of OT-II cells and eosinophils into PHIL mice resulted in the accumulation of effector T cells and a concomitant increase in both airway Th2 immune responses and histopathologies. Moreover, we show that eosinophils elicit the expression of the Th2 chemokines thymus- and activation-regulated chemokine/CCL17 and macrophage-derived chemokine/CCL22 in the lung after allergen challenge, and blockade of these chemokines inhibited the recruitment of effector T cells. In summary, the data suggest that pulmonary eosinophils are required for the localized recruitment of effector T cells.