Epithelial Cytokine Research Articles

The innate immune perspective of autoimmune and autoinflammatory conditions.

Innate immunity is one of two immune defence system arms. It is present at birth and does not require ‘learning’ through exposure to foreign organisms. It activates various mechanisms collectively to eliminate pathogens and hold an infection until the adaptive response are mounted. The innate immune system consists of four elements: the epithelial barrier, cells (e.g. macrophages, NK cells), plasma proteins (e.g. complement) and cytokines. These components act in concert to induce complex processes, as well as recruitment, activation and differentiation of adaptive responses. The innate response is more than just the ‘first line of defence’, as it essentially withholds the vast majority of any intruder, has a complex interplay with the adaptive arm and is crucial for survival of the host. Finally, yet importantly, a myriad of diseases has been linked with innate immune dysregulation. In this mini-review we will shed some light on these conditions, particularly regarding autoinflammatory ones.

Effects of E-cigarette E-liquid components on bronchial epithelial cells: Demonstration of dysfunctional efferocytosis.

E-cigarettes are often marketed and thought of as emitting harmless vapour; however, verification of their safety for non-smokers is scarce. We have previously shown that E-cigarettes cause decreased phagocytosis of bacteria by macrophages via reductions in surface bacterial recognition receptors. This study assessed the effect of E-cigarette constituents, 3 E-liquid apple flavours, nicotine, vegetable glycerine and propylene glycol, on bronchial epithelial cell viability, apoptosis and cytokine secretion and macrophage phagocytosis of apoptotic airway cells and phagocytic recognition molecules. Cell necrosis and apoptosis were measured by Sytox Green stain and Annexin V. Efferocytosis was measured by internalization of pHrodo Green labelled apoptotic airway cells by macrophages. Expression of macrophage cell surface apoptotic cell receptors was measured by flow cytometry. Cytokine release by E-cigarette-exposed airway cells was measured by cytokine bead array. E-cigarette vapour increased primary bronchial epithelial necrosis and apoptosis. E-cigarette vapour reduced efferocytosis (lowest flavour 12.1%) versus control (20.2%, P = 0.032). The efferocytosis receptor CD44 was reduced by one flavour (MFI 1863 vs 2332 control, P = 0.016) and all components reduced expression of CD36, including the glycol bases (MFI 1067-12 274 vs 1415 control). Reduced secretion of TNF-α, IL-6, IP-10, MIP-1α and MIP-1β was observed for all flavour variants. E-cigarettes can cause bronchial epithelial apoptosis and macrophage efferocytosis dysfunction via reduced expression of apoptotic cell recognition receptors. These data further show that E-cigarettes should not be considered harmless to non-smokers and their effects may go far beyond cytotoxicity to cells.

Transforming growth factor-β1 and eosinophil-derived neurotoxins contribute to the development of work-related respiratory symptoms in bakery workers

BackgroundIn baker's asthma previous studies suggest that adaptive and innate immunity are involved in the development of work-related respiratory symptoms (WRS), where we hypothesized that epithelial cells derive airway inflammation through modulating the release of inflammatory cytokines. Thus, we conducted this study to investigate the role of epithelial cell-derived cytokines in the development of WRS among bakery workers. MethodsWe recruited 385 wheat-exposed subjects with WRS (WRS+)/without WRS (WRS-) working in a single industry and 243 unexposed controls from Ajou Medical Center (Suwon, South Korea). Levels of epithelial cell-derived cytokines (interleukin [IL-8], transforming growth factor-β1 [TGF-β1], eotaxin-2) and inflammatory mediators (eosinophil-derived neurotoxins [EDN]) in sera or cell-free supernatants were measured by ELISA. Human airway epithelial cells (HAECs), A549, were stimulated by wheat flour extracts and co-cultured with peripheral blood neutrophils isolated from 4 asthmatic patients. ResultsSerum TGF-β1 levels were significantly lower in exposed subjects than in unexposed controls, in the WRS+ group than in the WRS- group (P < 0.001 for each). The WRS+ group had a significantly higher level of serum EDN than the WRS- group (P < 0.001). Serum TGF-β1 and EDN levels predicted the development of WRS in exposed subjects (area under the curve [AUC] = 0.719, 72.4% sensitivity/70% specificity; AUC = 0.759, 78.6% sensitivity/60% specificity). From wheat-stimulated HAECs, TGF-β1 release peaked at 6 hours after wheat exposure, while eotaxin-2 peaked at 12 hours. Co-culture of HAECs with neutrophils did not affect TGF-β1 release. ConclusionsOur results suggest that TGF-β1 may contribute to develop type-2 airway inflammation and WRS. Serum TGF-β1/EDN levels may be potential serum biomarkers for predicting WRS among bakery workers.

Alternaria induces airway epithelial cytokine expression independent of protease‐activated receptor

A novel fungal allergen, Alternaria (Alt), has been previously shown to associate with the pathogenesis of allergic rhinitis and bronchial asthma, particularly in arid and semi-arid regions. Airway epithelial cells are among the first to encounter Alt, and epithelial cytokine production and subsequent airway inflammation are early events in the response to Alt exposure. However, the underlying mechanism is unclear. As protease-activated receptor 2 (PAR2) has been implicated in most of the Alt-induced biological events, we investigated the regulation of airway inflammation and epithelial cytokine expression by PAR2. Wild-type (WT) and Par2 knockout (Par2-KO) mice were used to evaluate the in vivo role of PAR2. Primary human and mouse airway epithelial cells were used to examine the mechanistic basis of epithelial cytokine regulation in vitro. Surprisingly, Par2 deficiency had no negative impact on the change of lung function, inflammation and cytokine production in the mouse model of Alt-induced asthma. Alt-induced cytokine production in murine airway epithelial cells from Par2-KO mice was not significantly different from the WT cells. Consistently, PAR2 knockdown in human cells also had no effect on cytokine expression. In contrast, the cytokine expressions induced by synthetic PAR2 agonist or other asthma-related allergens (e.g. cockroach extracts) were indeed mediated via a PAR2-dependent mechanism. Finally, we found that EGFR pathway was responsible for Alt-induced epithelial cytokine expression. The activation of EGFR, but not PAR2, was likely to drive the airway inflammation and epithelial cytokine production induced by Alt.

MicroRNA-145-5p promotes asthma pathogenesis by inhibiting kinesin family member 3A expression in mouse airway epithelial cells.

BackgroundMicroRNA (miR)-145-5p is a respiratory disease biomarker, and is upregulated in asthma pathogenesis. However, its underlying mechanisms were unclear, so were investigated in the present study.MethodsA mouse model of asthma was established by challenge with house dust mite (HDM) extract. An miR-145-5p antagomir was administered nasally and expression of kinesin family member 3A (KIF3A) and miR-145-5p was measured by immunohistochemistry, PCR, and western blot. Eosinophils in lavage fluid and levels of interleukin (IL)-4, IL-5, and IL-13 were quantified. Airway hyper-responsiveness was measured and KIF3A expression was tested following miR-145-5p overexpression or interference in the 16HBE14o- airway epithelial cell line. The effects of miR-145-5p and KIF3A co-transfection in 16HBE14o- cells were examined on cytokine release, epithelial barrier dysfunction, and epithelial repair in HDM-exposed cells.ResultsKIF3A downregulation and miR-145-5p upregulation were noted in airway epithelial cells of HDM-exposed asthmatic mice, while miR-145-5p antagonism significantly improved symptoms. MiR-145-5p promoted the HDM-induced release of chemokines and inflammatory factors and epithelial barrier dysfunction, and suppressed epithelial repair by directly targeting KIF3A.ConclusionmiR-145-5p influenced HDM-induced epithelial cytokine release and epithelial barrier dysfunction via regulating KIF3 expression. It also affected epithelial repair, exacerbating the HDM-induced T helper 2-type immune response in mice.

Interaction of Alt a 1 with SLC22A17 in the airway mucosa.

Despite all the efforts made up to now, the reasons that facilitate a protein becoming an allergen have not been elucidated yet. Alt a 1 protein is the major fungal allergen responsible for chronic asthma, but little is known about its immunological activity. Our main purpose was to investigate the ligand-dependent interactions of Alt a 1 in the human airway epithelium. Alt a 1 with and without its ligand (holo- and apo- forms) was incubated with the pulmonary epithelial monolayer model, Calu-3 cells. Allergen transport and cytokine production were measured. Pull-down and immunofluorescence assays were employed to identify the receptor of Alt a 1 using the epithelial cell model and mouse tissues. Receptor-allergen-ligand interactions were analyzed by computational modeling. The holo-form could activate human monocytes, PBMCs, and polarized airway epithelial (Calu-3) cell lines. The allergen was also transported through the monolayer, without any alteration of the epithelial integrity (TEER). Alt a 1 also induced the production of proinflammatory IL8 and specific epithelial cytokines (IL33 and IL25) by Calu-3 cells. The interaction between epithelial cells and holo-Alt a 1 was found to be mediated by the SLC22A17 receptor, and its recognition of Alt a 1 was explained in structural terms. Our findings identified the Alt a 1 ligand as a central player in the interaction of the allergen with airway mucosa, shedding light into its potential role in the immunological response, while unveiling its potential as a new target for therapy intervention.

Benzo(a)pyrene facilitates dermatophagoides group 1 (Der f 1)-induced epithelial cytokine release through aryl hydrocarbon receptor in asthma.

BackgroundEnvironmental pollutants, which coexist with allergens, have been associated with the exacerbation of asthma. However, the underlying molecular mechanisms remain elusive. We sought to determine whether benzo(a)pyrene (BaP) co‐exposure with dermatophagoides group 1 allergen (Der f 1) can potentiate Der f 1‐induced asthma and its underlying mechanisms.MethodsThe effect of BaP was investigated in Der f 1‐induced mouse model of asthma, including airway hyper‐responsiveness, allergic inflammation, and epithelial‐derived cytokines. The impact of BaP on Der f 1‐induced airway epithelial cell oxidative stress (ROS) and cytokine release was further analyzed. The role of aryl hydrocarbon receptor (AhR) signaling in BaP‐promoted Der f 1‐induced ROS, cytokine production, and allergic inflammation was also investigated.ResultsCompared with Der f 1, BaP co‐exposure with Der f 1 led to airway hyper‐responsiveness and increased lung inflammation in mouse model of asthma. Increased expression of TSLP, IL‐33, and IL‐25 was also found in the airways of these mice. Moreover, BaP co‐exposure with Der f 1 activated AhR signaling with increased expression of AhR and CYP1A1 and promoted airway epithelial ROS generation and TSLP and IL‐33, but not IL‐25, expression. Interestingly, AhR antagonist CH223191 or cells with AhR knockdown abrogated the increased expression of ROS, TSLP, and IL‐33. Furthermore, ROS inhibitor N‐acetyl‐L‐cysteine (NAC) also suppressed BaP co‐exposure‐induced expression of epithelial TSLP, IL‐33, and IL‐25. Finally, AhR antagonist CH223191 and NAC inhibited BaP co‐exposure with Der f 1‐induced lung inflammation.ConclusionsOur findings suggest that BaP facilitates Der f 1‐induced epithelial cytokine release through the AhR‐ROS axis.

Divergent Effects of Acute and Prolonged Interleukin 33 Exposure on Mast Cell IgE-Mediated Functions.

Background: Epithelial cytokines, including IL-33 and Thymic stromal lymphopoietin (TSLP), have attracted interest because of their roles in chronic allergic inflammation-related conditions such as asthma. Mast cells are one of the major targets of IL-33, to which they respond by secreting cytokines. Most studies performed thus far have investigated the acute effects of IL-33 on mast cells. In the current study, we investigated how acute vs. prolonged exposure of mast cells to IL-33 and TSLP affects mediator synthesis and IgE-mediated activation.Methods: Human lung mast cells (HLMCs), cord blood-derived mast cells (CBMCs), and the ROSA mast cell line were used for this study. Receptor expression and the levels of mediators were measured after treatment with IL-33 and/or TSLP.Results: IL-33 induced the release of cytokines. Prolonged exposure to IL-33 increased while TSLP reduced intracellular levels of tryptase. Acute IL-33 treatment strongly potentiated IgE-mediated activation. In contrast, 4 days of exposure to IL-33 decreased IgE-mediated activation, an effect that was accompanied by a reduction in FcεRI expression.Conclusion: We show that IL-33 plays dual roles in mast cells, in which its acute effects include cytokine release and the potentiation of IgE-mediated degranulation, whereas prolonged exposure to IL-33 reduces IgE-mediated activation. We conclude that mast cells act quickly in response to the alarmin IL-33 to initiate an acute inflammatory response, whereas extended exposure to IL-33 during prolonged inflammation reduces IgE-mediated responses. This negative feedback effect suggests the presence of a novel regulatory pathway that modulates IgE-mediated human mast cell responses.

Distinct nasal airway bacterial microbiotas differentially relate to exacerbation in pediatric patients with asthma

In infants, distinct nasopharyngeal bacterial microbiotas differentially associate with the incidence and severity of acute respiratory tract infection and childhood asthma development. We hypothesized that distinct nasal airway microbiota structures also exist in children with asthma and relate to clinical outcomes. Nasal secretion samples (n=3122) collected after randomization during the fall season from children with asthma (6-17years, n=413) enrolled in a trial of omalizumab (anti-IgE) underwent 16S rRNA profiling. Statistical analyses with exacerbation as the primary outcome and rhinovirus infection and respiratory illnesses as secondary outcomes were performed. Using A549 epithelial cells, we assessed nasal isolates of Moraxella, Staphylococcus, and Corynebacterium species for their capacity to induce epithelial damage and inflammatory responses. Six nasal airway microbiota assemblages, each dominated by Moraxella, Staphylococcus, Corynebacterium, Streptococcus, Alloiococcus, or Haemophilus species, were observed. Moraxella and Staphylococcus species-dominated microbiotas were most frequently detected and exhibited temporal stability. Nasal microbiotas dominated by Moraxella species were associated with increased exacerbation risk and eosinophil activation. Staphylococcus or Corynebacterium species-dominated microbiotas were associated with reduced respiratory illness and exacerbation events, whereas Streptococcus species-dominated assemblages increased the risk of rhinovirus infection. Nasal microbiota composition remained relatively stable despite viral infection or exacerbation; only a few taxa belonging to the dominant genera exhibited relative abundance fluctuations during these events. Invitro, Moraxella catarrhalis induced significantly greater epithelial damage and inflammatory cytokine expression (IL-33 and IL-8) compared with other dominant nasal bacterial isolates tested. Distinct nasal airway microbiotas of children with asthma relate to the likelihood of exacerbation, rhinovirus infection, and respiratory illnesses during the fall season.

Local Probiotic Lactobacillus crispatus and Lactobacillus delbrueckii Exhibit Strong Antifungal Effects Against Vulvovaginal Candidiasis in a Rat Model.

A comprehensive knowledge of the vaginal ecosystem is critical for the development of successful approaches to the treatment of infections. The role of Lactobacilli in preventing vulvovaginal candidiasis (VVC) is controversial. In this study, we investigated the therapeutic effects and mechanism of Lactobacillus crispatus or delbrueckii on vaginitis caused by Candida albicans in a Sprague–Dawley rat model. A microbiological evaluation was performed by Gram staining and fungal colonies were enumerated. The antifungal efficacy of the two Lactobacillus strains was assessed by hematoxylin and eosin (HE) staining, transmission electron microscopy (TEM), immunohistochemical detection of interferon-γ (IFN-γ), interleukin (IL)-4, IL-17, and epithelial-derived IgG (RP125). Our in vitro results showed that the inhibitory activity against Candida colony-forming unit (CFU) counts was demonstrated by the two Lactobacillus strains (P < 0.001). Our results indicated that Lactobacillus administration played an indispensable role in maintaining the immune homeostasis, and decreasing the Th1/Th2 ratio (IFN-γ/IL-4) by regulating the epithelial secretion of cytokines that inhibit epithelial proinflammatory cytokine release, while increasing epithelial-derived IgG expression (P < 0.05), suggesting antibody-mediated protection. Our results implicate L. crispatus and L. delbrueckii as a potential adjunct biotherapeutic agent in women with VVC, especially for those with drug resistance, adverse effects or contraindications when using antifungal agents. Further large, long-term, well-planned clinical studies should be performed in clinical practice to determine their clinical potential of L. crispatus and L. delbrueckii as an adjunct treatment for VVC.

Th 9 cells in Behçet disease: Possible involvement of IL-9 in pulmonary manifestations

Behçet disease (BD) is a multisystemic disease some of whose manifestations are characterized by pulmonary involvements. The purpose of the study was to evaluate the level of T-helper type 9 (Th9) cells and the cytokine interleukin (IL)-9 in peripheral blood and in bronchoalveolar lavage (BAL) of patients with Behçet's disease (BD) affected by pulmonary manifestations. Nevertheless, until recently there have been no studies on its role in BD.The Th9 (CD4+IL-9+T) cell, transcription factor PU.1 and IL-9 mRNA levels, as well as serum and BAL IL-9 concentration, were measured in BD patients and healthy controls.The Th9 cell percentage and absolute number, PU.1 and IL-9 expression levels of BD patients were all increased significantly compared with the control group. Absolute number of Th9 cells was particularly increased in patients with active BD compared to inactive BD patients. The levels of IL-9 associated to Th9 expression depended on BD severity. These parameters were markedly expressed in the BAL of BD patients with pulmonary manifestations. IL-17 and the epithelial inflammatory cytokine TSLP were significantly correlated to IL-9 levels. This cytokine trio decreased in inactive BD patients after corticosteroïd treatment. In addition, IL-9 levels were correlated to CD4+ IL-9+ cells in BAL and in PBMCs. LPS stimulated PBMCs and macrophages induced increased secretion of IL-9 and the encoding transcription factors PU.1 and IRF4.In conclusion, the expansion of the Th9 cell subset, up-regulation of the PU.1 transcription factor and increased secretion of the IL-9 cytokine may contribute to the pathogenesis of BD, which may be supported by the increased release of IL-17 and TSLP. We provide evidence that Th9 T cells are increased in BD patients with pulmonary manifestations. This suggests an important role of IL-9 in the pathogenesis of BD particularly in patients suffering from lung involvement.

Immunity and resistance to cryptosporidiosis: the intricate ways of an enigmatic parasitosis

Genus Cryptosporidium includes around 30 known apicomplexan parasitic species which infect the gastrointestinal tract and rarely the respiratory system of more than 300 vertebrate animals. The immune response against infection by Cryptosporidium spp. includes all strata of innate and adaptive immunity with differences in their significance. The mucosal immunity, expressed predominantly by the “sentinel” role of epitheliocytes, is fundamental to the resistance against an infection (mainly via activation of the TLR4/NF-κB signalling axis). The vast array of epithelial chemokines and cytokines initiate the local inflammatory processes, attract effector cells and may directly suppress the parasite adhesion. The second line of defence includes IFN-γ-production by the NK cells in combination with their innate cytotoxicity against the parasite and the infected epitheliocytes. The adaptive immunity against the parasite depends predominantly on cytotoxic CD4+ Th1-lymphocytes, which makes IFN-γ central to the acquired response too. CD8+ cells aid to some extent the activity of Th1-cells but their involvement is not decisive. While Cryptosporidium infection elicits the synthesis of specific serum and mucosal antibodies, the humoral immunity is of minor importance. In immunocompromised hosts, infants and malnourished children, the mild and usually self-limiting infection can become life-threatening or take a chronic course. It is the second leading cause of fatal diarrhoea in children and one of the major opportunistic pathogens in the continually expanding group of patients with immunodeficiencies and systemic chronic diseases. Unravelling the mechanisms of resistance against Cryptosporidium infection is fundamental for the successful prevention of the disease.

Immunization with Leishmania major centrin knock-out (LmCen −/− ) parasites induces skin resident memory T cells that plays a role in protection against wild type infection (LmWT)

Abstract Leishmaniasis is a vector-born disease transmitted through sand fly bite with no available vaccine. Vaccination through leishmanization with Leishmania major has been used successfully but is not safe. Recently, we have demonstrated immunization with live attenuated LmCen−/− parasite protects against Leishmaniasis via induction of host cellular immunity. Resident memory T cells (TRMs) are considered the first line of defense against infections invading the host through epithelial barrier. We evaluated the generation and function of skin TRMs post LmCen−/− immunization, compared to that generated by LmWT healed mice. We examined chemokine receptors controlling the generation and survival of skin TRMs, as well as effector and recruitment function of those cells post challenge with WT parasites. We observed that expression of CXCR6 and CXCR3 was significantly higher on T cells from spleens and lymph nodes of immunized mice, compared to those from healed mice. At 15 weeks post immunization, the skin of immunized mice had significantly larger population of TRMs compared to healed mice. In addition, epithelial cytokine production, such as IL-15, IL-33 and TNFa was significantly higher in the skin of immunized mice. Upon virulent challenge, immunofluorescent labeling of skin sections showed rapid recruitment of more T cells in the immunized mice compared to healed mice. IFNγ production by skin TRMs post challenge was significantly higher in immunized mice compared to healed mice. Taken together, these results show that immunization with live attenuated parasites is safer than Leishmanization. In addition, it generates large functional population of skin TRMs which play an important role in protection against the Leishmania infection.

Heat treatment and irradiation reduce anti-bacterial and immune-modulatory properties of bovine colostrum

Abstract Colostrum contains bioactive components protecting the newborn intestine against bacteria. It is unclear how to optimize processing conditions with highest product bioactivity. Non-pasteurized (BC00), standard-pasteurized (72 °C-15 s, BC72), gently-pasteurized bovine colostrums without (63 °C-30 min, BC63) and with gamma-irradiation (BC63g) were tested for effects on bacterial growth inhibition (Escherichia coli, Staphylococcus aureus and S. epidermidis), intestinal epithelial cell (IEC) proliferation and cytokine secretion in vitro. Thermal processing decreased endogenous bacteria and IgG levels. All BCs inhibited bacterial growth 1–2 h after inoculation, but only BC00, BC63 and BC63g retained activity after 4–24 h. After 4 h, the activity against S. epidermidis of BC63g was lower than BC00 but still potent when mixed with formula. All BCs stimulated IEC proliferation, with the most pronounced responses for BC00. Only BC00 and BC63 increased IL-8 secretion in lipopolysaccharide-stimulated IECs. Thermal processing reduced bioactivity and combined gentle pasteurization and gamma-irradiation improved BC sterility and bioactivity, relative to standard pasteurization.

Epithelial cell-derived cytokines: more than just signaling the alarm.

The epithelial cell-derived cytokines thymic stromal lymphopoietin (TSLP), IL-33, and IL-25 are central regulators of type 2 immunity, which drives a broad array of allergic responses. Often characterized as "alarmins" that are released by the barrier epithelium in response to external insults, these epithelial cell-derived cytokines were initially thought to act only early in allergic inflammation. Indeed, TSLP can condition dendritic cells to initiate type 2 responses, and IL-33 may influence susceptibility to asthma through its role in establishing the immune environment in the perinatal lungs. However, TSLP, IL-33, and IL-25 all regulate a broad spectrum of innate immune cell populations and are particularly potent in eliciting and activating type 2 innate lymphoid cells (ILC2s) that may act throughout allergic inflammation. Recent data suggest that a TSLP/ILC axis may mediate steroid resistance in asthma. Recent identification of memory Th2 cell subsets that are characterized by high receptor expression for TSLP, IL-33, and IL-25 further supports a role for these cytokines in allergic exacerbations. There is therefore growing interest in developing biologics that target TSLP, IL-33, and IL-25. This Review provides an overview of TSLP, IL-33, and IL-25 and the development of blocking antibodies that target these epithelial cell-derived cytokines.

Butyrate Does Not Protect Against Inflammation-induced Loss of Epithelial Barrier Function and Cytokine Production in Primary Cell Monolayers From Patients With Ulcerative Colitis.

Background and Aims In vitro studies using immortalised cancer cell lines showed that butyrate has an overall positive effect on epithelial barrier integrity, but the physiological relevance of cancer cell lines is limited. We developed epithelial monolayers from human tissue samples of patients with ulcerative colitis [UC] to assess the effect of butyrate on epithelial barrier function.MethodsA protocol to establish monolayers from primary epithelial cells of UC patients [n = 10] and non-UC controls [n = 10] was optimised. The monolayers were treated with 8 mM sodium butyrate ± tumour necrosis factor alpha [TNFα] and type II interferon [IFNγ] for 48 h. Changes in transepithelial electrical resistance were monitored. Barrier gene expression levels were measured. Inflammatory proteins in the supernatant of the cells were quantified with OLINK.ResultsWe demonstrated that primary monolayer cultures can be grown within 1 week of culture with robust resistance values and polarised tight junction expression. Butyrate treatment of the cultures increased resistance but was detrimental in combination with TNFα and IFNγ. The combined treatment further induced even higher IL8 mRNA and inflammatory protein secretion than for the inflammatory mediators alone. The observed effects were similar in cultures from patients and non-UC controls, suggesting that there were no patient-specific responses responsible for these findings.ConclusionsWe found that butyrate does not protect against inflammation-induced barrier dysfunction and even worsens its effects in primary epithelial monolayers of UC patients and controls. The basic mechanisms of butyrate should therefore be reconsidered in future studies, in particular in patients with active inflammation and pre-existing barrier defects as is known for UC.

Contributions of Innate Lymphoid Cells in Chronic Rhinosinusitis.

To review innate lymphoid cells (ILCs) and their role in chronic rhinosinusitis (CRS). The immune system consists of the innate and adaptive response. Until the recognition of ILCs, chronic inflammatory diseases were characterized by cytokines linked only to T helper cells. However, these immune responses are now described more broadly to include contributions from both the innate and adaptive immunity. In CRS, focus had been on ILC2s in CRS with nasal polyps. These studies also highlight the importance of epithelial cell-derived cytokines in coordinating these responses. In addition to indirect crosstalk via cytokines, ILCs and T helper cells can utilize the OX40/OX40 ligand and major histocompatibility complex class II pathways to directly interact and coordinate responses. In addition to T helper cells, ILCs contribute to the inflammatory response associated with CRS. The understanding of these cells along with pathways that activate and perpetuate these cells leads to new potential therapeutic targets for CRS treatment.

Profibrotic epithelial phenotype: a central role for MRTF and TAZ

Epithelial injury is a key initiator of fibrosis but - in contrast to the previous paradigm - the epithelium in situ does not undergo wide-spread epithelial-mesenchymal/myofibroblast transition (EMT/EMyT). Instead, it assumes a Profibrotic Epithelial Phenotype (PEP) characterized by fibrogenic cytokine production. The transcriptional mechanisms underlying PEP are undefined. As we have shown that two RhoA/cytoskeleton-regulated transcriptional coactivators, Myocardin-related transcription factor (MRTF) and TAZ, are indispensable for EMyT, we asked if they might mediate PEP as well. Here we show that mechanical stress (cyclic stretch) increased the expression of transforming growth factor-β1 (TGFβ1), connective tissue growth factor (CTGF), platelet-derived growth factor and Indian Hedgehog mRNA in LLC-PK1 tubular cells. These responses were mitigated by siRNA-mediated silencing or pharmacological inhibition of MRTF (CCG-1423) or TAZ (verteporfin). RhoA inhibition exerted similar effects. Unilateral ureteral obstruction, a murine model of mechanically-triggered kidney fibrosis, induced tubular RhoA activation along with overexpression/nuclear accumulation of MRTF and TAZ, and increased transcription of the above-mentioned cytokines. Laser capture microdissection revealed TAZ, TGFβ1 and CTGF induction specifically in the tubular epithelium. CCG-1423 suppressed total renal and tubular expression of these proteins. Thus, MRTF regulates epithelial TAZ expression, and both MRTF and TAZ are critical mediators of PEP-related epithelial cytokine production.

CHANGES OF INNATE IMMUNITY INDEXES IN SEVERE ASTHMA IN CHILDREN

At the present time, the role of innate immunity in pathogenesis of bronchial asthma (BA) is actively studied, in particular, significance of TLRs and cytokines. The study included 42 patients with severe bronchial asthma (from 3 to 12 years old), and 67 healthy children at the same age. Expression of TLR2, TLR4, and TLR9 genes was evaluated by PCR-RT from the scrapings of nasal mucosa; cytokines (IL-33, TSLP, IL-4, TGF-β1 and IL-28B) were assayed in nasal swabs by ELISA technique. The main results were as follows: an increased gene expression of TLR2, TLR4, TLR9 genes was revealed in the nasal mucosa scraps from the patients with bronchial asthma as compared to healthy children. We have also measured the contents of important cytokines secreted by the respiratory epithelium in the course of TLRs activation. The study of IL-33, TSLP, IL-4 in nasal samples revealed significantly increased concentrations of these cytokines in the patients with severe BA against the control group. A study of TGF-βlevels in nasal cavity swabs revealed a significant decrease of this regulatory cytokine in the group of pediatric patients with asthma. Worth of note, evaluation of antiviral IL-28B cytokine in the group of patients with severe BA showed a significant downward trend, in comparison to the control indexes. Hence, one may conclude on some disturbances of local innate immunity system in the patients with severe BA which manifest as hyperexpression of TLRs genes, increased production of proinflammatory and epithelial cytokines, decreased production of antiviral IL-28B cytokine, and TGF-β1.

Role of transient receptor potential cation channel subfamily V member 1 (TRPV1) on ozone-exacerbated allergic asthma in mice

Around the globe, worsening air pollution is spawning major public health and environmental concerns, especially in the poorest and most populous cities. As a major secondary air pollutant, ozone is a potential risk factor for exacerbated asthma, although the underlying mechanisms remain uncertain. In this study, we aim to investigate the role of ozone on asthma exacerbation using a classic asthmatic model with allergic airway inflammation by treating Balb/c mice with ovalbumin (OVA). Our study shows ozone exposure significantly exacerbated OVA-induced asthmatic phenotypes, including serum immunoglobulin, Th cytokines, inflammatory cell counts, mucus production, airway remodeling, and airway hyper-responsiveness (AHR). Interestingly, expression of transient receptor potential cation channel subfamily V member1 (TRPV1) was also significantly elevated in ozone-exacerbated asthmatic mice and that treatment with TRPV1 antagonist effectively suppressed AHR, airway inflammation and remodeling. The underlying mechanisms of these effects may be associated with suppression of neuropeptide calcitonin gene-related peptide (CGRP) and thymic stromal lymphopoietin (TSLP), an epithelial cell-derived cytokine. Base on the role of TRPV1 in allergic asthma, this study further revealed that inhibition of TRPV1 by TRPV1 antagonist has significant anti-inflammatory effects on ozone-induced asthma exacerbation in this study. Induction of TRPV1 expression may be an important mechanism underlying the increased risks for asthma after exposure to environmental pollutants.