Interleukin-6 is essential for Staphylococcal exotoxin B-induced T regulatory cell insufficiency in nasal polyps

The interplay of Pseudomonas aeruginosa and Staphylococcus aureus in dual-species biofilms impacts development, antibiotic resistance and virulence of biofilms in in vitro wound infection models

Due to high tolerance to antibiotics and pronounced virulence, bacterial biofilms are considered a key factor and major clinical challenge in persistent wound infections. They are typically composed of multiple species, whose interactions determine the biofilm's structural development, functional properties and thus the progression of wound infections. However, most attempts to study bacterial biofilms in vitro solely rely on mono-species populations, since cultivating multi-species biofilms, especially for prolonged periods of time, poses significant challenges. To address this, the present study examined the influence of bacterial composition on structural biofilm development, morphology and spatial organization, as well as antibiotic tolerance and virulence on human skin cells in the context of persistent wound infections. By creating a wound-mimetic microenvironment, the successful cultivation of dual-species biofilms of two of the most prevalent wound pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, was realized over a period of 72 h. Combining quantitative analysis with electron microscopy and label-free imaging enabled a comprehensive evaluation of the dynamics of biofilm formation and matrix secretion, revealing a twofold increased maturation of dual-species biofilms. Antibiotic tolerance was comparable for both mono-species cultures, however, dual-species communities showed a 50% increase in tolerance, mediated by a significantly reduced penetration of the applied antibiotic into the biofilm matrix. Further synergistic effects were observed, where dual-species biofilms exacerbated wound healing beyond the effects observed from either Pseudomonas or Staphylococcus. Consequently, predicting biofilm development, antimicrobial tolerance and virulence for multi-species biofilms based solely on the results from mono-species biofilms is unreliable. This study underscores the substantial impact of a multi-species composition on biofilm functional properties and emphasizes the need to tailor future studies reflecting the bacterial composition of the respective in vivo situation, leading to a more comprehensive understanding of microbial communities in the context of basic microbiology and the development of effective treatments.

A Higher Dose of Staphylococcus aureus Enterotoxin B Led to More Th1 and Lower Th2/Th1 Ratio in Th Cells

Exposure to Staphylococcus aureus enterotoxin B (SEB) is one of the causes of food poisoning and is associated with several immune diseases due to its superantigen capability. This study aimed to characterize the differentiations of naïve Th cells stimulated with different doses of SEB. The expression of T-bet, GATA-3, and Foxp3 or secretion of IFN-γ, IL-4, IL-5, IL-13, and IL-10 were evaluated in wild-type (WT) or DO11.10 CD4 T cells co-cultured with bone marrow dendritic cells (BMDCs). We found that the balance of Th1/Th2 could be dominated by the doses of SEB stimulation. A higher SEB dose could induce more Th1 and a lower Th2/Th1 ratio in Th cells co-cultured with BMDCs. This different tendency of Th cell differentiation induced by the SEB complements the existing knowledge about SEB acting as a superantigen to activate Th cells. Additionally, it is also helpful in managing the colonization of S. aureus and food contamination of SEB.

Autoimmunity: A New Focus on Nasal Polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) has long been considered a benign, chronic inflammatory, and hyperplastic disease. Recent studies have shown that autoimmune-related mechanisms are involved in the pathology of nasal polyps. Activated plasma cells, eosinophils, basophils, innate type 2 lymphocytes, mast cells, and proinflammatory cytokine in polyp tissue indicate the mobilization of innate and adaptive immune pathways during polyp formation. The discovery of a series of autoantibodies further supports the autoimmune nature of nasal polyps. Local homeostasis dysregulation, infection, and chronic inflammation may trigger autoimmunity through several mechanisms, including autoantigens overproduction, microbial translocation, molecular mimicry, superantigens, activation or inhibition of receptors, bystander activation, dysregulation of Toll-Like Receptors (TLRs), epitope spreading, autoantigens complementarity. In this paper, we elaborated on the microbiome-mediated mechanism, abnormal host immunity, and genetic changes to update the role of autoimmunity in the pathogenesis of chronic rhinosinusitis with nasal polyps.

Inhibition of fracture healing in the presence of contamination by Staphylococcus aureus: Effects of growth state and immune response

Extremity injuries comprise a significant portion of trauma, affecting quality of life, financial burden, and return to duty. Bacterial contamination is commonly associated with failure to heal, despite antibiotic treatment, suggesting that additional therapies must be developed to combat these complications. Treatment failure is likely due to the presence of resistant microbial communities known as biofilms. Biofilm bacteria are able to elicit a direct inhibition of healing through a multitude of known factors. However, they likely also inhibit healing through alteration of the inflammatory response. As inflammation is a critical step in fracture healing, how the presence of biofilm bacteria shifts this response to one that is suboptimal for healing is an important consideration that is currently understudied. The profile of inflammatory factors in response to biofilm bacteria is unique and distinct from those induced during normal healing or by planktonic bacteria alone. This review will examine the presence of inflammatory factors during normal healing and those induced by contaminating bacteria, and will discuss how these differences may ultimately lead to nonunion. Specifically, this review will focus on the Th1/Th2/Th17 type inflammatory responses and how shifts in the balance of these responses during infection can lead to both ineffective clearance and disruption of fracture healing. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1845-1854, 2017.

Expression and Regulation of Transcription Factor FoxA2 in Chronic Rhinosinusitis With and Without Nasal Polyps

Purpose

Chronic rhinosinusitis (CRS) is characterized by the excessive production of mucus. However, the molecular mechanism underlying mucin overproduction in CRS with or without nasal polyps (CRSwNP and CRSsNP, respectively) is poorly understood. This study was conducted to assess the importance of the transcription factor FoxA2 in mucin production and to investigate the targeting of FoxA2 as a potential therapeutic strategy for mucus hypersecretion in CRS patients.

Methods

We enrolled 15 CRSwNP patients, 15 CRSsNP patients, and 10 normal controls in this study. The expression levels of FoxA2, MUC5AC, and MUC5B in inflamed and healthy nasal tissues were examined via immunohistochemistry and quantitative reverse transcription-polymerase chain reaction, and the levels of several proinflammatory cytokines in nasal secretions were measured via FlowCytomix analysis. In addition, the expression of MUC5AC and FoxA2 was determined in polyp-derived epithelial cells and NCI-H292 cells after in vitro stimulation.

Results

FoxA2 was significantly down-regulated, and MUC5AC and MUC5B were significantly up-regulated in both the CRSwNP and CRSsNP patients compared to the controls (P<0.05), and the protein level of FoxA2 was negatively associated with the IL-6 level in the CRS patients (P<0.05). IL-6 significantly increased MUC5AC expression but inhibited FoxA2 expression in vitro (P<0.05). Transfection with a FoxA2 expression plasmid significantly decreased MUC5AC promoter activity (P<0.05) and inhibited IL-6-induced MUC5AC production (P<0.05). In addition, clarithromycin significantly alleviated IL-6-induced FoxA2 suppression and decreased MUC5AC expression in vitro (P<0.05).

Conclusions

Our findings suggest that FoxA2 may be considered a therapeutic target for the modulation of mucus hypersecretion in CRS patients.

Expression of heme oxygenase-1 in eosinophilic and non-eosinophilic chronic rhinosinusitis with nasal polyps: modulation by cytokines

BACKGROUND

Oxidative stress is characteristic of chronic airway inflammatory diseases such as asthma, chronic obstructive pulmonary disease and chronic rhinosinusitis with nasal polyps (CRSwNP). Heme oxygenase (HO)-1 has been proposed to be a cytoprotective enzyme against oxidative stress in CRSwNP. However, the expression and regulation of HO-1 in eosinophilic CRSwNP (ECRS) and non-eosinophilic CRSwNP (non-ECRS) subsets has not been well documented.

METHODS

Nasal polyps and uncinate process tissues were enrolled from 40 CRSwNP patients (ECRS, 17; non-ECRS, 23) and 20 control subjects, respectively. The messenger RNA (mRNA) and protein expression of HO-1 was examined using qRT-PCR, immunohistochemistry, and Western blot staining. Moreover, the stimulatory effects of several cytokines (interferon γ [IFN-γ], interleukin [IL]-5, and IL-13, etc.) on HO-1 mRNA expression in cultured nasal explants were evaluated.

RESULTS

The mRNA and protein expression of HO-1 was significantly increased in polyp tissues compared with healthy controls (p < 0.05), and the non-ECRS subset showed significantly increased HO-1 expression compared with the ECRS subset (p < 0.05). Moreover, in cultured nasal explant, HO-1 mRNA was significantly upregulated in the presence of IFN-γ, IL-27, IL-5, IL-13, and IL-17A, but was significantly inhibited by transforming growth factor β1 (TGF-β1) (p < 0.05).

CONCLUSION

Our findings indicate that HO-1 was differentially expressed and regulated in ECRS and non-ECRS patients.

Comparative Exoproteomics and Host Inflammatory Response in Staphylococcus aureus Skin and Soft Tissue Infections, Bacteremia, and Subclinical Colonization

The exoproteome of Staphylococcus aureus contains enzymes and virulence factors that are important for host adaptation. We investigated the exoprotein profiles and cytokine/chemokine responses obtained in three different S. aureus-host interaction scenarios by using two-dimensional gel electrophoresis (2-DGE) and two-dimensional immunoblotting (2D-IB) combined with tandem mass spectrometry (MS/MS) and cytometric bead array techniques. The scenarios included S. aureus bacteremia, skin and soft tissue infections (SSTIs), and healthy carriage. By the 2-DGE approach, 12 exoproteins (the chaperone protein DnaK, a phosphoglycerate kinase [Pgk], the chaperone GroEL, a multisensor hybrid histidine kinase, a 3-methyl-2-oxobutanoate hydroxymethyltransferase [PanB], cysteine synthase A, an N-acetyltransferase, four isoforms of elongation factor Tu [EF-Tu], and one signature protein spot that could not be reliably identified by MS/MS) were found to be consistently present in more than 50% of the bacteremia isolates, while none of the SSTI or healthy-carrier isolates showed any of these proteins. By the 2D-IB approach, we also identified five antigens (methionine aminopeptidase [MetAPs], exotoxin 15 [Set15], a peptidoglycan hydrolase [LytM], an alkyl hydroperoxide reductase [AhpC], and a haptoglobin-binding heme uptake protein [HarA]) specific for SSTI cases. Cytokine and chemokine production varied during the course of different infection types and carriage. Monokine induced by gamma interferon (MIG) was more highly stimulated in bacteremia patients than in SSTI patients and healthy carriers, especially during the acute phase of infection. MIG could therefore be further explored as a potential biomarker of bacteremia. In conclusion, 12 exoproteins from bacteremia isolates, MIG production, and five antigenic proteins identified during SSTIs should be further investigated for potential use as diagnostic markers.

Role of Staphylococcal Enterotoxin B on the Differentiation of Regulatory T Cells in Nasal Polyposis

Background

The pathogenesis of nasal polyposis has not been fully understood. Recent studies indicate that there is a subset of CD4+CD25high FoxP3+T cells (regulatory T cells [Tregs]) that express retinoic acid receptor related orphan receptor C (RORC) or IL-17, and these cells might be new proinflammatory cells because of the expression of IL-17 with loss of their suppressive function. The goals of this study were to localize Th17-like Tregs (Th17-like Tregs or RORC+Tregs) in nasal polyps and to investigate the role of staphylococcal enterotoxin B (SEB) on the differentiation of Tregs to RORC+Tregs in vitro.

Methods

A total of 60 patients were enrolled in this study. Of the 60 patients, 40 had chronic rhinosinusitis with nasal polyps (CRSwNPs), and 20 subjects who were undergoing septoplasty were enrolled as control subjects. The nasal polyps of CRSwNP patients were subclassified as either eosinophilic polyp (EP) and noneosinophilic polyp (NEP) according to the result of hematoxylin and eosin stain. Tissues and whole blood were collected from all subjects. Double immunofluorescent staining and reverse-transcription polymerase chain reaction for RORC and FOXP3 were conducted on the tissues. RORC expressions of Tregs were measured in the tissue using flow cytometry. The proportions of RORC+Tregs subsets and cytokines profiles from the supernatant were measured using flow cytometry after stimulation with SEB.

Results

The cells that express both RORC and FOXP3 and RORC+Tregs were significantly higher in the nasal polyps, especially in EPs compared with NEPs, and control mucosa. RORC+Tregs in peripheral blood mononuclear cells significantly increase in patients with EPs 24 hours after SEB stimulation in vitro.

Conclusion

The results indicate that SEB may be involved in the differentiation of Tregs to RORC+Tregs, and these cells may be involved in the pathogenesis of eosinophilic nasal polyposis.

Role of hypoxia-inducible factor-1α expression in regulatory T cells on nasal polypogenesis

OBJECTIVES/HYPOTHESIS

Hypoxia-inducible factor-1α (HIF-1α) is considered as a key molecule in regulating Th17:regulatory T-cells (Tregs) balance. The aims of this study were to investigate whether HIF-1α is associated with the RORγ (RAR-related orphan receptor gamma) expression of Tregs in nasal polyps and to verify whether Staphylococcus enterotoxin B (SEB) is involved in this process.

STUDY DESIGN

Clinical experimental study.

METHODS

Forty patients with chronic rhinosinusitis with nasal polyposis were enrolled and divided into eosinophilic nasal polyps (EPs) and noneosinophilic nasal polyps (NEPs) according to the proportion of eosinophils. Fifteen subjects who were undergoing septoplasty were enrolled as control subjects. Expression of HIF-1α in the tissue was measured using reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot, and flow cytometry. The mRNA expression of RORC (RAR-related orphan receptor C) and HIF-1α in Tregs separated from tissues were measured by RT-PCR. Double immunofluorescent staining for RORC/FOXP3 and HIF-1α/FOXP3 were conducted on the tissues. Expression of RORC and HIF-1α in Tregs from peripheral blood mononuclear cells (PBMCs) was measured using flow cytometry after stimulation with SEB.

RESULTS

Expression of RORC and HIF-1α in Tregs was significantly higher in EPs and NEPs compared with control mucosa, and there was a significant correlation between RORC and HIF-1α expression in Tregs. Expression of RORC and HIF-1α mRNA in Tregs separated from the tissues was also significantly higher in nasal polyps compared with control mucosa. Expression of RORC and HIF-1α in Tregs were increased after 24-hour stimulation with SEB in the PBMCs.

CONCLUSIONS

HIF-1α-induced RORC expression in Tregs may play a key role in the pathogenesis of nasal polyps.

Convergence of two major pathophysiologic mechanisms in nasal polyposis: immune response to Staphylococcus aureus and airway remodeling

This review is addressed two pathophysiologic mechanisms implicated in the pathogenesis of nasal polyposis: the unique remodeling process found in nasal polyp tissue and the immune response of patients with nasal polyposis to Staphylococcus aureus.

These two theories converge to the same direction in different aspects, including decreased extracellular matrix production, impaired T regulation and favoring of a Th2 immune response.

In patients with nasal polyposis, an exaggerated immune response to Staphylococcus aureus may aggravate the airway remodeling process.

Correlation between cytokine levels in nasal fluid and eosinophil counts in nasal polyp tissue in asthmatic and non-asthmatic patients

BACKGROUND/AIMS

Concentrations of mediators in nasal secretions could reflect the inflammatory status of the nasal mucosa and evolution of sinus disease. So, the aim of our study was to evaluate local immune reaction by measuring crucial Th1, Th2 and inflammatory cytokines in nasal fluid samples of patients with nasal polyps (NP), and to correlate them to clinical, radiological findings and to the degree of eosinophil infiltration of polyp tissue. Therefore, in our study we compared the cytokine levels in nasal fluid of asthmatic and non-asthmatic patients with nasal polyposis, the eosinophil counts in NP tissues of these patients, and we correlated cytokine levels with eosinophil counts in NP tissue specimens.

MATERIAL AND METHODS

Thirty patients with nasal polyposis (NP) (15 asthmatic and 15 non-asthmatic) were included in this prospective study. Nasal secretion samples were collected from nasal cavities of all subjects. The levels of 11 cytokines (TNF-α, TNF-β, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, and IFN-γ) were measured using commercial flow cytometric kit. Eosinophils were counted in haematoxylin-and-eosin-stained NP sections.

RESULTS

The concentrations of Th2 cytokines IL-5, IL-6, IL-10, and Th1 cytokine IFN-γ were significantly higher in patients with NP and asthma compared with non-asthmatic subjects. A positive correlation was found between IL-6 and TNF-α levels in nasal fluid and eosinophil counts in polyp tissue in non-asthmatic subjects. In asthmatic NP patients, we found positive correlation between level of IL-6 and eosinophil counts and negative correlation between IFN-γ level and number of eosinophils in NP tissue specimens.

CONCLUSION

Our results showed that these patients with similar clinical findings had significantly different mediator profiles in their nasal secretions, implying clear differences in pathogenesis of their NP.

Developments in the field of allergy in 2009 through the eyes of Clinical and Experimental Allergy

In 2009 the journal published in the region of 200 papers including reviews, editorials, opinion pieces and original papers that ran the full gamut of allergic disease. It is instructive to take stock of this output to determine patterns of interest and where the cutting edge lies. We have surveyed the field of allergic disease as seen through the pages of Clinical and Experimental Allergy (CEA) highlighting trends, emphasizing notable observations and placing discoveries in the context of other key papers published during the year. The review is divided into similar sections as the journal. In the field of Asthma and Rhinitis CEA has contributed significantly to the debate about asthma phenotypes and expressed opinions about the cause of intrinsic asthma. It has also added its halfpennyworth to the hunt for meaningful biomarkers. In Mechanisms the considerable interest in T cell subsets including Th17 and T regulatory cells continues apace and the discipline of Epidemiology continues to invoke a steady stream of papers on risk factors for asthma with investigators still trying to explain the post-second world war epidemic of allergic disease. Experimental Models continue to make important contributions to our understanding of pathogenesis of allergic disease and in the Clinical Allergy section various angles on immunotherapy are explored. New allergens continue to be described in the allergens section to make those allergen chips even more complicated. A rich and vibrant year helpfully summarized by some of our associate editors.

Murine immune response to a chronic Staphylococcus aureus biofilm infection

Staphylococcus aureus has reemerged as an important human pathogen in recent decades. Although many infections caused by this microbial species persist through a biofilm mode of growth, little is known about how the host's adaptive immune system responds to these biofilm infections. In this study, S. aureus cells adhered to pins in culture and were subsequently inserted into the tibiae of C57BL/6 mice, with an infecting dose of 2 × 10⁵ CFU. This model was utilized to determine local cytokine levels, antibody (Ab) function, and T cell populations at multiple time points throughout infection. Like human hosts, S. aureus implant infection was chronic and remained localized in 100% of C57BL/6 mice at a consistent level of approximately 10(7) CFU/gram bone tissue after day 7. This infection persisted locally for >49 days and was recalcitrant to clearance by the host immune response and antimicrobial therapy. Local inflammatory cytokines of the Th1 (interleukin-2 [IL-2], IL-12 p70, tumor necrosis factor alpha [TNF-α], and IL-1β) and Th17 (IL-6 and IL-17) responses were upregulated throughout the infection, except IL-12 p70, which dwindled late in the infection. In addition, Th1 Ab subtypes against a biofilm antigen (SA0486) were upregulated early in the infection, while Th2 Abs and anti-inflammatory regulatory T cells (Tregs) were not upregulated until later. These results indicate that early Th1 and Th17 inflammatory responses and downregulated Th2 and Treg responses occur during the development of a chronic biofilm implant infection. This unrestrained inflammatory response may cause tissue damage, thereby enabling S. aureus to attach and thrive in a biofilm mode of growth.

T cell inflammatory response, Foxp3 and TNFRS18-L regulation of peripheral blood mononuclear cells from patients with nasal polyps-asthma after staphylococcal superantigen stimulation

BACKGROUND

Staphylococcal superantigens may modulate airway inflammatory disease.

OBJECTIVE

We assessed the effect of Staphylococcus aureus enterotoxin B (SEB) on T cell activation in patients with nasal polyps and asthma, and its possible link to aspirin hypersensitivity.

METHODS

Leucocytes were isolated from five healthy subjects (controls), five asthmatics with nasal polyps without (NP-ATA) and five with aspirin-induced asthma (NP-AIA). Cells were incubated with increasing concentrations of SEB for 4 and 18 h. Release of T(H)1/T(H)2 cytokines was assessed by Cytometric Bead-Array. Foxp3 and TNFRS18-L expression were analysed by qPCR and flow cytometry.

RESULTS

After 4 and 18 h, SEB significantly increased IFN-gamma, IL-4, TNF-alpha, IL-5 and IL-2 concentrations in supernatants of both NP polyp groups compared with controls. Baseline Foxp3 was significantly decreased in both NP-asthma groups. Incubation with SEB for 4 h induced a limited up-regulation of Foxp3 in NP-AIA patients, which was switched off consecutively. Foxp3 was significantly up-regulated in the control group after 18 h, but not in the NP-asthmatic groups. In parallel, TNFRS18-L mRNA significantly increased after 18 h in the NP-asthma groups compared with control subjects. This molecule was highly expressed in CD11c(+)CD14(+) cells and its levels increased after 18 and 24 h culture in the NP-asthma patients.

CONCLUSION

SEB induces both T(H)1 and T(H)2 pro-inflammatory responses in patients with nasal polyps and asthma regardless of the presence of aspirin hypersensitivity. The nature of this response may be linked to a basal deficiency of Foxp3 observed in the NP-asthmatic patients and/or to the up-regulation of TNFRS18-L on monocytes/dendritic cell precursors.

Forkhead box P3+ T cells express interleukin-17 in nasal mucosa of patients with both allergic rhinitis and polyposis

The pathogenesis of nasal polyposis remains unclear; it severely affects patients' quality of life and complicates inflammation in adjacent organs such as sinusitis and asthma. Aberrant immune regulatory function in these patients is proposed. The present study aims to examine the regulatory T cells (T(reg) ) in nasal mucosa of patients with allergic rhinitis (AR) and nasal polyposis (NP). Patients with AR or AR/NP were treated with inferior turbinectomy for their inferior turbinate hyperplasia. Surgically removed nasal mucosa was collected to examine the T(reg) by immunohistochemistry and flow cytometry. The results showed that more forkhead box P3 (FoxP3)(+) cells were found in AR with polyps than in those with AR alone. Further studies revealed that these FoxP3(+) T cells from AR/NP group also expressed interleukin (IL)-17. In vitro study showed that staphylococcal enterotoxin B (SEB) induced CD4(+) FoxP3(+) T cells to become FoxP3(+) IL-17(+) cells via facilitating the expression of IL-6, that in synergy with transforming growth factor-beta, induce the expression of IL-17 in FoxP3(+) cells. We conclude that FoxP3(+) IL-17(+) T cells were localized in the nasal mucosa of patients with AR and NP. SEB may play a role in converting FoxP3(+) T(reg) to FoxP3(+) IL-17(+) T cells. The presence of IL-17(+) FoxP3(+) T cells may play a role in the remodelling of the nasal airways in certain people who develop polyps, irrespective of whether or not they are atopic.

Staphylococcus aureus invades the epithelium in nasal polyposis and induces IL-6 in nasal epithelial cells in vitro

BACKGROUND

Staphylococcus aureus has been associated with chronic rhinosinusitis with nasal polyps (CRSwNP) pathogenesis but its role is still controversially discussed. Here, we demonstrate S. aureus detection in the mucosa of CRSwNP. In addition, intracellular residency of S. aureus in nasal polyp epithelial cells (NPECs) and its capability to induce TH-2 cytokines were analyzed in vitro.

METHODS

Staphylococcus aureus detection in CRSwNP (n = 25), CRS without polyps (CRSsNP, n = 5), and turbinate mucosa (TM, n = 10) was performed by peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) and microbial cultivation from tissue biopsies. Intracellular residency was examined by intracellular persistence assay and electron microscopy. IL-6 and IL-13 responses to S. aureus infection and supernatants were quantified by ELISA.

RESULTS

Peptide nucleic acid-fluorescence in situ hybridization positive bacterial cells were significantly increased in the epithelium of CRSwNP (17/25) compared to CRSsNP (0/5) and TM (1/10). Good concordance of PNA-FISH results and S. aureus cultivation was found applying Cohen's κ for CRSwNP (κ = 0.841) and TM (κ = 1.0). Intracellular persistence assay with S. aureus strain Newman and its corresponding small-colony variant mutant strain III33 demonstrated intracellular survival and replication of S. aureus within NPECs. Both S. aureus strains significantly induced IL-6 but not IL-13 in infected NPECs and in NPECs challenged with corresponding staphylococcal supernatants.

CONCLUSION

Invasion of the epithelium by S. aureus was a phenomenon seen predominantly in CRSwNP. Regardless of an intra- or extracellular localization in the epithelium, S. aureus is capable to induce IL-6 synthesis in vitro and thus may contribute to the TH-2 cytokine pattern in CRSwNP.

The systemic and pulmonary immune response to staphylococcal enterotoxins

In response to environmental cues the human pathogen Staphylococcus aureus synthesizes and releases proteinaceous enterotoxins. These enterotoxins are natural etiologic entities of severe food poisoning, toxic shock syndrome, and acute diseases. Staphylococcal enterotoxins are currently listed as Category B Bioterrorism Agents by the Center for Disease Control and Prevention. They are associated with respiratory illnesses, and may contribute to exacerbation of pulmonary disease. This likely stems from the ability of Staphylococcal enterotoxins to elicit powerful episodes of T cell stimulation resulting in release of pro-inflammatory cytokines. Here, we discuss the role of the immune system and potential mechanisms of disease initiation and progression.

Opposing roles of IL-17A and IL-25 in the regulation of TSLP production in human nasal epithelial cells

BACKGROUND

The importance of IL-17A, IL-17F, and IL-25 in allergic rhinitis (AR), as well as their possible role in regulation on thymic stromal lymphopoietin (TSLP) production in nasal epithelial cells, is not well understood.

OBJECTIVE

To determine the possible regulation of IL-17A, IL-17F, and IL-25 on TSLP production in the initiation of allergic responses.

METHODS

The levels of IL-17A, IL-17F, IL-25, and TSLP in nasal lavages of patients with AR were measured using an enzyme-linked immunosorbent assay (ELISA) and compared with that in normal controls. Then, primary human nasal epithelial cells (HNECs) were stimulated with dsRNA (0-75 microg/ml), as well as IL-17A (100 ng/ml), IL-17F (100 ng/ml), and IL-25(100 ng/ml). The mRNA expression of IL-17A, IL-17F, IL-25, TSLP, as well as the chemokines CCL20, IL-8, and eotaxin was analyzed using quantitative real-time PCR, and their protein levels in the supernatants of cultured HNECs were determined by ELISA.

RESULTS

Both TSLP and IL-17 cytokines are significantly elevated in patients with AR. dsRNA was found to increase the production of IL-17F, IL-25, TSLP, CCL20, and IL-8 in HNECs. Furthermore, IL-25 significantly enhanced dsRNA-induced TSLP production in primary HNECs and was dominant to the inhibitory effect of IL-17A on TSLP regulation.

CONCLUSIONS

Our study provides the first evidence that both IL-17F and IL-25 can be induced by dsRNA in HNECs. Despite of the opposing effects of IL-17A and IL-25 on TSLP regulation in HNECs, IL-25 was dominant to IL-17A, providing a plausible explanation for the simultaneous upregulation of IL-17 cytokines and TSLP in patients with AR.

Cytokine Profiles in Nasal Fluid in Patients with Nasal Polyps: A Flow Cytometric Study

Biological markers in nasal fluid provide valuable information on nasal pathophysiology. The aims of this study were to compare the cytokine profiles of nasal fluid in subjects with nasal polyps (NP) and co-morbid asthma and NP patients without asthma and to determine the role of these cytokines in the development of NP. Thirty patients with NP (15 asthmatic and 15 non asthmatic) were included in this prospective study. Nasal secretion samples were collected from nasal cavities of all 30 subjects. The levels of eleven cytokines (TNF-α, TNF-β, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, and IFN-γ) were measured using flow cytometry. The concentrations of Th2 cytokines IL-5, IL-6 and IL-10 were significantly higher in patients with NP and asthma compared with subjects with NP without asthma. We also found significantly higher levels of IFN-α, IL-4, IL-6 and IL-10 in allergic patients with NP and asthma compared with those without asthma. In nonallergic patients with NP and asthma, the concentrations of TNF-α, IL-5 and IL-6 were significantly higher than in nonallergic patients with NP without asthma. Our results show that the presence of Th2 cytokines, especially IL-5 and IL-6 in patients with NP and asthma is a more prominent feature than in those without asthma that relates to the increased eosinophilic inflammation. We have also found a significant influence of allergy on the cytokine profiles both in asthmatic and nonasthmatic patients.