Akira Fukumoto

Induction of eotaxin production by interleukin-4, interleukin-13 and lipopolysaccharide by nasal fibroblasts

Background There is growing evidence that eotaxin is a key mediator in the development of tissue eosinophilia. Fibroblasts are a major source of eotaxin. The severity of diseases with eosinophilic inflammation like nasal polyposis, atopic dermatitis and asthma, where Th2‐type cytokines (IL‐4 and IL‐13) and TGF‐β are expressed locally, was shown to correlate with bacterial factors such as lipopolysaccharide (LPS) rather than allergen.

IL-5 and Eotaxin Levels in Middle Ear Effusion and Blood from Asthmatics with Otitis Media with Effusion

Objective--The purpose of this study was to evaluate eosinophil infiltration as well as IL-5 and eotaxin levels in middle ear effusion (MEE) and blood from otitis media with effusion (OME) patients with asthma and to compare the findings with those from OME patients without asthma (control group). Material and methods--Levels of IL-5 and eotaxin in MEE and blood were measured by means of enzyme-linked immunosorbent assay. Results--IL-5 levels in MEE were significantly higher than those in blood in both groups of patients and in OME patients with asthma than in the control group. In addition, in OME patients with asthma, there was a significant correlation between the percentage of eosinophils and IL-5 levels in MEE. Eotaxin levels in blood were significantly higher than those in MEE in both groups of patients and in OME patients with asthma than in the control group. In addition, in OME patients with asthma, the percentage of eosinophils and eotaxin levels in blood tended to correlate, but did not reach statistical significance. Conclusion--These data suggest that, in OME patients with asthma, eosinophilia in MEE depends more on IL-5 than on eotaxin, and that eotaxin may play an important role in the mobilization of eosinophils from the bone marrow into the blood.

Heterogeneous response of nasal and lung fibroblasts to transforming growth factor‐β1

Background Nasal polyposis is characterized by marked oedema, sparse extracellular matrix (ECM) and proliferating blood vessels. Pulmonary fibrosis is characterized by inflammatory cells accumulation, considerable ECM deposition and vascular abnormalities. Although lung fibrosis is not only and necessarily an inflammatory disorder, we hypothesized that the difference between nasal polyposis and pulmonary fibrosis may, in part, be due to the heterogeneity between nasal and lung fibroblasts. Fibroblasts participate in the inflammatory response by releasing ECM proteins and cytokines. TGF‐β is thought to participate in chronic inflammation and fibrosis. Myofibroblasts are the activated form of fibroblasts. A phenotypic hallmark of myofibroblasts is the expression of smooth muscle α‐actin (SMA).

Synergistic induction of thymic stromal lymphopoietin by tumor necrosis factor alpha and Th2 cytokine in nasal polyp fibroblasts.

Background Thymic stromal lymphopoietin (TSLP) is elevated in airway inflammatory diseases such as asthma and triggers dendritic cell–mediated activation of Th2 inflammatory responses. Although allergic chronic sinusitis is a Th2 inflammatory disease of the upper airway, the mechanism underlying the predominance of Th2 responses still has to be clarified. We investigated the expression of TSLP in cytokine-treated nasal polyp fibroblasts. Methods Fibroblast lines were established from nasal polyp tissues. Their expression of TSLP mRNA was evaluated by real-time reverse-transcription polymerase chain reaction. The amount of TSLP in the supernatants was measured by enzyme-linked immunosorbent assay. Results Nasal polyp fibroblasts have the capacity to produce TSLP in response to stimulation by tumor necrosis factor (TNF) alpha. Combined stimulation with TNF-alpha + a Th2 cytokine (IL-4 or IL-13) was synergistic for TSLP production by the nasal polyp fibroblasts. This response was time and dose dependent. The TNF-alpha + Th2 cytokine (IL-4 or IL-13)–induced TSLP production was strongly inhibited by interferon gamma but not by IL-10. Conclusions These results suggest that nasal polyp fibroblasts play a role in the development and regulation of Th2-type inflammation in the upper airway by producing TSLP.

Toll-like receptor 2, 3, 4, 5 ligands and interleukin-4 synergistically induce TARC production in nasal polyp fibroblasts

OBJECTIVE Although type 2 T helper (Th2) cytokines such as IL-4 and IL-5 play a crucial role in the pathogenesis of chronic sinusitis with allergy, the mechanism underlying the predominance of Th2 cytokines has yet to be clarified. Thymus and activation-regulated chemokine (TARC) has been known to facilitate the recruitment of Th2 polarized cells, resulting in high levels of Th2 cytokines in the sinus mucosa as well as nasal polyps. The nasal and sinus cavities are ideal sites for studying the interplay between microbial Toll-like receptor (TLR) ligands and chemokines. We investigated whether nasal polyp fibroblasts produce TARC when stimulated with the breakdown products of microorganisms (TLR ligands) and a Th2 cytokine (IL-4). METHODS Fibroblast lines were established from nasal polyp tissues. The expression of TARC mRNA was evaluated by real-time RT-PCR. The amount of TARC in the supernatants was measured by ELISA. RESULTS Combined stimulation with TLR 2, 3, 4, 5 ligands and IL-4 induced TARC gene expression and protein production in the cultured nasal polyp fibroblasts. This response was time-dependent. CONCLUSIONS These results suggest that nasal polyp fibroblasts contribute to innate immunity and may play an important role in the recruitment of Th2 cells into nasal polyps through the production of TARC.

Induction of TARC production by lipopolysaccharide and interleukin-4 in nasal fibroblasts.

Background: Th2 cell infiltration is a characteristic feature of allergic chronic sinusitis. However, the mechanisms that cause the predominance of Th2 cells in this disease have yet to be clarified. The airway is often exposed to not only Th2 cytokines but also bacterial products such as lipopolysaccharides (LPS). A CC chemokine, TARC, is a potent chemoattractant for Th2 cells. The objectives of this study were twofold. First, we examined whether nasal polyp fibroblasts were able to produce TARC when costimulated with LPS and IL-4. Second, we investigated whether there was any heterogeneity in TARC production among fibroblasts derived from different airway sites. Methods: Fibroblast lines were established from human biopsy tissue. The amount of TARC in the supernatants was measured by ELISA. The expression of TARC mRNA was quantitated by real-time PCR. Results: Combined stimulation with LPS and IL-4 significantly induced TARC production by nasal polyp fibroblasts in a dose- and time-dependent manner. This induction occurred in normal nasal fibroblasts, but not in normal lung fibroblasts. Conclusions: Via TARC production, nasal fibroblasts may play an important role in the recruitment of Th2 cells into the sinus mucosa as well as nasal polyps. The heterogeneity in TARC production may reflect functional differences between upper and lower airway fibroblasts.

Nasal polyp fibroblasts produce MIP-3alpha in response to toll-like receptor ligands and cytokine stimulation.

OBJECTIVE Dendritic cells (DCs) play important roles in the development and perpetuation of immune responses. DCs are present in upper airway diseases such as chronic rhinosinusitis with nasal polyps. However, the mechanisms of how DCs migrate into the upper airway mucosa during upper airway inflammatory diseases remains unclear. Macrophage inflammatory protein-3alpha (MIP-3alpha) is known to be a migratory factor for immature DCs. There have been very few reports regarding cells producing this chemokine in the airways. To investigate this, we stimulated fibroblasts cultured from the nasal polyps with various toll-like receptor (TLR) ligands, which are derived from microorganisms, and IL-beta1 and TNF-alpha, which are proinflammatory cytokines, and analyzed their ability to produce MIP-3alpha. METHODS Fibroblast lines were established from nasal polyps and stimulated with TLR2, 3, 4, 5, 7/8 and 9 ligands, IL-beta1 and TNF-alpha. MIP-3alpha mRNA expression in nasal polyp fibroblasts (NPF) was evaluated by real-time RT-PCR and the protein levels of MIP-3alpha in the supernatants of stimulated NPF was measured by ELISA. RESULTS Stimulation with TLR2, 3, 4 and 5 ligands, IL-beta1 and TNF-alpha, induced MIP-3alpha gene expression and protein production in the cultured NPF This response was dose- and time-dependent. CONCLUSION NPF possibly play an important role in the recruitment of DCs in upper airway diseases such as chronic rhinosinusitis with nasal polyps through the production of MIP-3alpha.

Combined Stimulation with Poly(I:C), TNF-α and Th2 Cytokines Induces TARC Production by Human Fibroblasts from the Nose, Bronchioles and Lungs

Background: Th2 cells trigger allergic diseases in the respiratory tract. However, the mechanisms that cause Th2 cell infiltration remain unclear. Viral infections exacerbate allergic diseases in the respiratory tract. Thymus- and activation-regulated chemokine (TARC) recruits Th2 cells to sites of inflammation. Resident fibroblasts are thought to contribute to inflammatory cell infiltration through chemokine production. We compared the abilities of nasal, bronchiolar and lung fibroblasts to produce TARC. Methods: Expression of TARC mRNA was evaluated by real-time RT-PCR, while the amount of TARC in supernatants was measured by ELISA. Results: Costimulation with TNF-α and Th2 cytokines (IL-4, IL-13) or with poly(I:C) and Th2 cytokines (IL-4, IL-13) induced TARC production by nasal (polyp and normal) fibroblasts. Costimulation with TNF-α and Th2 cytokines (IL-4, IL-13) also induced TARC production by both bronchiolar and lung fibroblasts, but costimulation with poly(I:C) and Th2 cytokines (IL-4, IL-13) caused no induction. Combined exposure of cells to poly(I:C), TNF-α and Th2 cytokines (IL-4, IL-13) resulted in substantial production of TARC by nasal and lung fibroblasts, but much less by bronchiolar fibroblasts. Conclusions:TARC is directly inducible in diverse fibroblast populations from the respiratory tract (nose, bronchioles and lungs), but the mechanisms and levels of TARC production differ. Fibroblasts in the respiratory tract may contribute to Th2 cell infiltration and viral-induced exacerbation of allergic diseases, such as allergic sinusitis, asthma and allergic lung inflammation.

Synergistic Induction of Macrophage Inflammatory Protein-3α;/CCL20 Production by Interleukin-17A and Tumor Necrosis Factor-α; in Nasal Polyp Fibroblasts.

BackgroundAccumulation of T cells and immature dendritic cells (DCs) is one of the characteristic features of nasal polyps. However, the question remains why these cells accumulate in nasal polyp tissue. Macrophage inflammatory protein-3α (MIP-3α/CCL20) is a chemokine involved in the migration of T cells and immature DCs into inflammatory tissue sites. Fibroblasts are a rich source of cytokines and chemokines. The objective of this study was to demonstrate the expression of MIP-3α/CCL20 in nasal polyp fibroblasts after stimulation with proinflammatory cytokines such as interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α).MethodsFibroblast lines were established from nasal polyps. MIP-3α/CCL20 mRNA expression was evaluated by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR). The amount of MIP-3α/CCL20 in the supernatants was measured by enzyme-linked immunosorbent assay (ELISA).ResultsIL-17A and TNF-α synergistically induced MIP-3α/CCL20 production by nasal polyp fibroblasts in a dose- and time-dependent manner. This synergy was observed by stimulation with TNF-α plus IL-17A or IL-17F, but not IL-17E.ConclusionsNasal polyp fibroblasts, by producing MIP-3α/CCL20, may play an important role in the recruitment of T cells and DCs in upper airway inflammatory lesions such as nasal polyps.

Expression of MCP-4 by TLR ligand-stimulated nasal polyp fibroblasts

Conclusion. These results indicate that nasal polyp fibroblasts contribute to innate immunity and eosinophilic inflammation such as nasal polyposis. Objective. It is generally accepted that type 2 T helper (Th2) cytokines and some chemoattractants play an essential role in the pathogenesis of nasal polyposis. Nasal polyposis is characterized by chronic eosinophilic inflammation. The mechanisms that cause the predominance of eosinophilic infiltration in nasal polyposis have yet to be clarified. There is growing evidence that fibroblasts could be a major source of Th2 chemokines. Because the nasal and paranasal mucosae are the first respiratory tissues that environmental agents encounter, those tissues are exposed to injurious agents, including microorganisms and their breakdown products. We investigated whether nasal polyp fibroblasts produce a C-C chemokine, MCP-4, when stimulated with the breakdown products of microorganisms and a Th2 cytokine (interleukin (IL)-4). Materials and methods. Fibroblast lines were established from nasal polyp tissues. The expression of MCP-4 mRNA was evaluated by real-time RT-PCR. The amount of MCP-4 in the supernatants was measured by ELISA. Results. TLR2, 3, 4 and 5 ligands, but not TLR7/8 or 9 ligands, induced small amounts of MCP-4. TLR2, 3, 4 and 5 ligands synergized with IL-4 to induce the production of MCP-4.