Intratracheal exposure to Fab fragments of an allergen‐specific monoclonal antibody regulates asthmatic responses in mice

Fab fragments (Fabs) maintain the ability to bind to specific antigens but lack effector functions due to the absence of the Fc portion. In the present study, we tested whether Fabs of an allergen‐specific monoclonal antibody (mAb) were able to regulate asthmatic responses in mice. Asthmatic responses were induced in BALB/c mice by passive sensitization with anti‐ovalbumin (OVA) polyclonal antibodies (pAbs) (day 0) and by active sensitization with OVA (days 0 and 14), followed by intratracheal (i.t.) challenge with OVA on day 1 and days 28, 29, 30 and 35. Fabs prepared by the digestion of an anti‐OVA IgG1 (O1‐10) mAb with papain were i.t. administered only once 30 min before antigenic challenge on day 1 or day 35. The results showed that i.t. administration of O1‐10 Fabs with OVA markedly suppressed the early and/or late phases of asthmatic responses caused by passive and active sensitization. Similar results were obtained when Fabs of anti‐OVA IgG2b mAb (O2B‐3) were i.t. administered. In contrast, neither i.t. injection of intact 01‐10/O2B‐3 nor systemic injection of O1‐10 Fabs suppressed the asthmatic responses. In vitro studies revealed that the capture of OVA by O1‐10 Fabs prevented the subsequent binding of intact anti‐OVA pAbs to the captured OVA. These results suggest that asthmatic responses may be down‐regulated by the i.t. exposure to Fabs of an allergen‐specific mAb via a mechanism involving the capture of allergen by Fabs in the respiratory tract before the interaction of intact antibody and allergen essential for the induction of asthmatic responses.     

白介素17单克隆抗体对变应性鼻炎小鼠气道炎症的作用

目的 探讨白介素17单克隆抗体（IL-17mAb）的不同给予剂量及方式在变应性鼻炎小鼠气道炎症中的作用。方法 将48只小鼠采用随机数字表法分为A、 B、 C、 D、 E、 F组,每组8只。分别于第0、 7、 14 d将20 μg卵清蛋白（OVA）加2 mg铝佐剂腹腔注射处理A、C、D、E及F组小鼠,间隔7 d,第22天开始进行鼻腔激发,每天每侧鼻孔各给予OVA 10 μl（共500 μg）滴鼻,连续7 d。A、C、D、E组小鼠于每次OVA鼻腔激发前1 h分别给予生理盐水、100 ng IL-17mAb、500 ng IL-17mAb、5 μg IL-17mAb滴鼻,F组小鼠于每次OVA鼻腔激发前4 h给予5 μg IL-17mAb腹腔注射,B组小鼠于相同时间点给予等量生理盐水腹腔注射及滴鼻。所有小鼠于最后1次激发后评估鼻部症状学变化,Diff-Quik染色观察鼻腔灌洗液（NLF）中嗜酸性粒细胞浸润情况,ELISA方法检测血清及NLF中IL-6、IL-10水平,鼻黏膜组织行甲苯胺蓝染色观察肥大细胞。结果 ４周末A组所有小鼠症状学评分均＞5分,提示造模成功。F组小鼠的挠鼻及喷嚏次数均少于A组（P＜0.05）;F组小鼠NLF中嗜酸性粒细胞数、血清IL-6水平低于A组,血清及NLF中IL-10水平均高于A组（P＜0.05）;E组小鼠血清中IL-10水平高于A组（P＜0.05）;A组小鼠鼻黏膜组织中肥大细胞数多于B组,统计学意义显著（P＜0.01）;F组小鼠鼻黏膜组织中肥大细胞数少于A组,但差异无统计学意义（P＞0.05）;F组小鼠鼻黏膜组织中肥大细胞数与B组比较,差异无统计学意义（P＞0.05）。结论 高剂量的（5 μg）IL-17mAb腹腔注射处于激发阶段的变应性鼻炎小鼠促使小鼠变应性鼻炎症状明显减轻,鼻腔灌洗液嗜酸性粒细胞减少。促使变应性鼻炎小鼠血清中IL-6表达降低,血清中及鼻腔灌洗液中IL-10表达升高,因此推测这些细胞因子的变化可能抑制Th17/促进Treg的分化,进而对变态反应产生抑制作用。     

Ameliorative effect of acetylshikonin on ovalbumin (OVA)‐induced allergic rhinitis in mice through the inhibition of Th2 cytokine production and mast cell histamine release

Acetylshikonin has long been known as an anti‐inflammatory and antioxidative reagent. However, the anti‐allergic effect has not been studied. The aim of this study was to evaluate the effect of acetylshikonin on allergic rhinitis (AR) in mice. Mice were sensitized by intraperitoneal injection of OVA and aluminum hydroxide and challenged with intranasal instillation of OVA. Acetylshikonin was administered orally after nasal cavities challenge. Severity of allergic rhinitis was assessed according to nasal symptoms; serum OVA‐specific immunoglobulin E (IgE), IgG1, and IgG2a level; and interleukin (IL)‐4, IL‐10, IL‐5, IL‐13, TNF‐α, IL‐12, and interferon (INF)‐γ levels in nasal lavage fluid (NALF). Additionally, the histological change and the release of histamine in serum and nasal lavage fluid were evaluated by acid‐Schiff stain and ELISA. Acetylshikonin attenuated manifestation of nasal symptoms in sensitized mice and inhibited production of Th2‐related OVA‐specific IgE, IgG1, and Th2 cell‐produced IL‐4, IL‐5, IL‐13, and mast cell produced histamine; however, it had no effect on Th1 cell‐produced cytokines, like INF‐γ. In addition, the degree of inflammatory cell infiltration and goblet cell hyperplasia was attenuated by acetylshikonin treatment. Our results suggest that acetylshikonin effectively reduces allergic inflammation in a mouse model of allergic rhinitis by its anti‐allergic and anti‐inflammatory properties.     

Basophil and eosinophil accumulation and mast cell degranulation in the nasal mucosa of patients with hay fever after local allergen provocation

BACKGROUND: Basophils and mast cells have certain similarities and are believed to be important in upper and lower respiratory allergy. OBJECTIVE: We sought to apply immunohistology to investigate the distribution and numbers of mast cells and basophils in the nasal mucosa after allergen provocation. METHODS: Allergen challenge with grass pollen was performed in 9 patients with seasonal allergic rhinitis out of the hay fever season. Nasal biopsy specimens were taken before and approximately 1 hour, 24 hours, and 1 week after intranasal allergen provocation. We determined relative numbers and their phenotypic characteristics by using mAbs specific for tryptase, chymase, IgE, eosinophils (BMK-13), and a new mAb against basophils (BB1) by using immunohistochemistry in frozen sections. RESULTS: In the nasal mucosa at baseline, practically no basophils were found in the epithelium. A significant increase in numbers was found in the epithelium and lamina propria of the nasal mucosa in the early phase as early as 1 hour after allergen provocation. At 24 hours and 1 week after allergen provocation, a significant increase in basophil numbers was found in the lamina propria only. The proportion of mast cells staining for chymase in the lamina propria decreased from a median of 38% (range, 0%-82%) to 14% (range, 0%-78%) within 1 hour of allergen provocation. The proportion of mast cells staining for chymase increased from 1% (range, 0%-86%) at baseline to 21% (range, 3%-85%) within 1 hour of allergen provocation. One week after provocation, mast cells returned to baseline numbers. A definite tissue eosinophilia was observed after allergen provocation. CONCLUSION: Basophil numbers are increased in the epithelium and lamina propria of the nasal mucosa of subjects with rhinitis after allergen challenge, with influx already apparent at 1 hour. Moreover, changes in mast cell percentages and numbers were observed within 1 hour of allergen provocation.     

Establishment and characterization of a murine model for allergic asthma using allergen-specific IgE monoclonal antibody to study pathological roles of IgE

Allergen-specific IgE has long been regarded as a major molecular component of allergic asthma. Although IgE plays a central role in the early asthmatic response, its roles in the chronic phase, such as the late asthmatic response, airway hyperresponsiveness (AHR), and airway remodeling (goblet cell hyperplasia and subepithelial fibrosis) have not yet been defined well. In this study, we investigated the hypothesis that chronic responses could be induced by IgE-dependent mechanisms. BALB/c mice passively sensitized with an ovalbumin (OVA)-specific IgE monoclonal antibody (mAb) were repeatedly challenged with intratracheal administration of OVA. The first challenge induced early phase airway narrowing without any late response, but the fourth challenge caused not only an early but also a late phase response, AHR, and goblet cell hyperplasia. Macrophages, lymphocytes and neutrophils, but not eosinophils, were significantly increased in the lung 24 h after the fourth challenge. Interestingly, levels of OVA-specific IgG1 in serum increased by multiple antigen challenges. A C3a receptor antagonist inhibited the late asthmatic response, AHR, and infiltration by neutrophils. In contrast, no late response, goblet cell hyperplasia, inflammatory cells, or production of IgG1 was observed in severe combined immunodeficient mice. On the other hand, seven challenges in BALB/c mice induced subepithelial fibrosis associated with infiltration by eosinophils. In conclusion, the allergic asthmatic responses induced by passive sensitization with IgE mAb can provide a useful model system to study the pathological roles of IgE in acute and chronic phases of allergic asthma.     

Eosinophil recruitment to nasal nerves after allergen challenge in allergic rhinitis

In allergen challenged animal models, eosinophils localize to airway nerves leading to vagally-mediated hyperreactivity. We hypothesized that in allergic rhinitis eosinophils recruited to nasal nerves resulted in neural hyperreactivity. Patients with persistent allergic rhinitis (n = 12), seasonal allergic rhinitis (n = 7) and controls (n = 10) were studied. Inferior nasal turbinate biopsies were obtained before, 8 and 48 h after allergen challenge. Eight hours after allergen challenge eosinophils localized to nerves in both rhinitis groups; this was sustained through 48 h. Bradykinin challenge, with secretion collection on the contralateral side, was performed to demonstrate nasal nerve reflexes. Twenty four hours after allergen challenge, bradykinin induced a significant increase in secretions, indicating nasal hyperreactivity. Histological studies showed that nasal nerves expressed both vascular cell adhesion molecule-1 (VCAM-1) and chemokine (C-C motif) ligand 26 (CCL-26). Hence, after allergen challenge eosinophils are recruited and retained at nerves and so may be a mechanism for neural hyperreactivity.     

Eotaxin but not MCP-3 induces eosinophil influx into nasal fluid in allergic patients

BACKGROUND: Eotaxin and MCP-3 (CC chemokines), owing to their preferential action on eosinophils, seem to be the very importance in the patophysiology of allergic rhinitis and asthma. The purpose of this study was to examine the effect of intranasally administered eotaxin and MCP-3 after specific allergen priming on the influx of inflammatory cells and their soluble mediators into the nasal mucosa.METHODS: Eotaxin and MCP-3 have been applied intranasally at the increasing doses of 1, 5 and 10 microg to allergic patients after allergen priming. The 'nasal pool' technique was used. The cell count and biochemical parameters in nasal lavage were evaluated before 30 min, and 4 and 24 h after the challenge with chemokines.RESULTS: Both eotaxin and MCP-3 induced the increase in clinical 'score' lasting till 24 h. Eosinophil influx into nasal mucosa after provocation with eotaxin was also observed. The challenge with MCP-3 did not induce any significant changes in nasal lavage fluid.CONCLUSIONS: Eotaxin is likely to play an important role in the pathogenesis of allergic conditions in humans. MCP-3 did not induce inflammatory cell influx into nasal mucosa. The role of this chemokine in the pathogenesis of allergic inflammation is difficult to assess and requires further studies.     

Antiallergic Function of KR62980, a Peroxisome Proliferator-Activated Receptor-γ Agonist,in a Mouse Allergic Rhinitis Model

Purpose

Peroxisome proliferator-activated receptor γ (PPAR-γ) has been shown to play an important role in the control of inflammatory responses acting on macrophages, mast cells, T cells and eosinophils. A novel PPAR-γ ligand, KR62980 have been recently focused on due to the lower undesirable effects than other PPAR-γ ligands such as rosiglitazone and pioglitazone. The present study was aimed to investigate the effects of KR62980 on nasal symptoms and immunopathological profiles in allergic nasal mucosa in murine allergic rhinitis model.

Methods

BALB/c mice were sensitized and challenged intranasally with ovalbumin (OVA). KR62980 was administered intraperitoneally or orally 3 hours before each intranasal OVA challenge.

Results

Administration of KR62980 significantly decreased the number of nasal rubbing, nasal sneezing, ova-specific IgE and total IgE in serum, secretion of Interleukin (IL)-4, IL-5, and IL-17 from the spleen and eosinophilic infiltration in the nasal mucosa. KR62980 decreased the expression of IL-4, IL-5 and IL-10 mRNAs in the nasal mucosal tissue, while, it elevated the level of IL-10 and IFN-γ in splenocyte culture. KR62980 seemed to decrease IL-17 level in local and systemic level even though it did not reach to statistical significance. The anti-inflammatory effect was more definite when the KR62980 was administered intraorally than intraperitoneally.

Conclusions

A novel PPAR-γ ligand, KR62980 can attenuate OVA-induced allergic inflammation in mice mainly through modulation of Th2 cytokines. This finding suggests that PPAR-γ might have a role in the treatment of allergic rhinitis.     

Effect of allergen immunotherapy on nasal responses in guinea-pigs with allergic rhinitis

Methods We have investigated the effects of allergen immunotherapy on the nasal responses in the guinea-pigs with allergic rhinitis. Thirty-three male Hartley guinea-pigs with allergic rhinitis were divided into three groups; those receiving intradermal injection of saline (Group 1) or 0.1% ovalbumin (Group 2) 6 days after the last intranasal sensitization, and those injected with 0.1% ovalbumin intradermally once daily for 6 consecutive days from the next day after the last intranasal sensitization (Group 3). Results The dye leakage and histamine content into the nasal lavage significantly decreased at 30min after antigen challenge in Group 3, compared with Group 1 or 2. We also observed the change of mast cell numbers in superficial nasal mucosa, lamina propria and injected dorsal skin. The number of mast cells in superficial nasal mucosa significantly decreased in Group 3 compared with Group 1 or 2, but not those in nasal lamina propria or dorsal skin. Conclusions These results suggest that the improvements of nasal responses such as dye leakage and histamine content may be caused by the decrease of mast cell numbers in the superficial mucosal layer after the specific immunotherapy. which may be developing tolerance and one of the mechanisms underlying the beneficial effect of immunotherapy.     

The central role of CD30L/CD30 interactions in allergic rhinitis pathogenesis in mice

CD30 ligand (CD30L) plays an important role in the amplification and/or activation of effector CD4(+) T cells, irrespective of Th cell subset. To examine the role of CD30L in allergic rhinitis, we evaluated an OVA model of allergic rhinitis in CD30L knock out (KO) mice on a BALB/c background sensitized with OVA. Symptoms of allergic rhinitis such as eosinophil infiltration into the nasal mucosa were drastically diminished in OVA-sensitized CD30L KO mice following intranasal challenge with OVA. The levels of OVA-specific IgE in the sera and the Th2 response in nasopharynx-associated lymphoid tissues and cervical LNs of CD30L KO mice were significantly lower than those of WT mice following intranasal challenge with OVA. Intranasal administration of CD30-Ig during the effector phase with OVA significantly prevented the development of allergic rhinitis in WT mice. These results suggest that CD30L plays an important role in allergic rhinitis and that the inhibition of CD30L/CD30 signaling might be useful as a novel biological therapy for allergic rhinitis.     

Mast cell regulation of epithelial TSLP expression plays an important role in the development of allergic rhinitis

Epithelial cell-derived thymic stromal lymphopoietin (TSLP) is a master switch for asthma or atopic dermatitis by inducing a dendritic cell-mediated Th2-type allergic inflammation. Allergic rhinitis is also pathologically characterized by Th2-type allergic inflammation. This study demonstrates that mast cells regulate the epithelial TSLP expression in allergic rhinitis. TSLP expression was found to be up-regulated predominantly in the nasal epithelium in the ovalbumin (OVA)-sensitized and -nasally challenged mouse model of allergic rhinitis, which was abolished in mast cell-deficient WBB6F1-W/W(v) in comparison with control WBB6F1-+/+ mice. Similarly, the epithelial TSLP expression was reduced in Fc receptor gamma chain (FcgammaR)-deficient mice, where the high-affinity IgE receptor (FcepsilonRI) is not expressed on mast cells, in comparison with control C57BL/6 mice. Furthermore, the administration of neutralizing TSLP antibody during the challenge phase of OVA inhibited the development of allergic rhinitis. These results suggest that the direct stimulation of epithelial cells by antigens alone may not be sufficient to induce TSLP expression in the nasal epithelium, and that mast cell regulation of epithelial TSLP expression, possibly via FcepsilonRI, plays an important role in the development of allergic rhinitis.     

Desloratadine partially inhibits the augmented bacterial responses in the sinuses of allergic and infected mice

BACKGROUND: Allergic rhinitis (AR) is considered a major predisposing factor for the development of acute bacterial rhinosinusitis. How AR augments a bacterial infection is unknown. OBJECTIVE: Our purpose in this study was to test whether an H1 receptor antagonist, desloratadine, could reduce the augmented effect of an ongoing allergic reaction on acute bacterial rhinosinusitis. METHODS: Three groups of infected and ovalbumin (OVA)-sensitized mice were studied: (1) infected and allergic mice treated with desloratadine, (2) infected and allergic mice treated with placebo, and (3) infected mice. A fourth group of uninfected, non-sensitized mice served as a control for the cellular changes. BALB/c mice were sensitized by two intraperitoneal injections of OVA given 8 days apart. One day after the second injection, the mice were nasally exposed daily to 6% OVA (the groups treated with desloratadine or placebo) or phosphate-buffered saline (PBS) (the infection-only group) for 5 days. After the second OVA exposure, the mice were intranasally inoculated with Streptococcus pneumoniae. Desloratadine or placebo was given daily throughout the OVA exposure period. Nasal allergic symptoms were observed by counting of nasal rubbing and sneezing for 10 min after OVA or PBS nasal challenge. On day 5 post-infection, nasal lavage culture was done, and the inflammatory cells in the sinuses were evaluated by flow cytometry. RESULTS: Mice that were made allergic, infected, and treated with placebo showed more organisms and phagocytes than did only infect mice. They also manifested allergic nasal symptoms and eosinophil influx into the sinuses. Desloratadine treatment during allergen exposure reduced allergic symptoms and reduced sinonasal infection (P<0.05). There tended to be less myeloid cell and neutrophil influx (P=0.09 both), but not eosinophil influx (P=0.85) compared with that in the placebo-treated group. CONCLUSION: Desloratadine treatment during nasal challenge inhibited allergic symptoms and reduced sinonasal infection, suggesting that histamine via an H1 receptor plays a role in the augmented infection in mice with an ongoing allergic reaction.     

The inflammatory nature of allergic disease

The allergic inflammatory response in allergic rhinitis has been studied extensively owing to the high frequency of the condition, the significant morbidity it causes and the accessibility of the nasal tissue. The allergic inflammatory response is characterized by IgE synthesis, IgE-dependent mast cell activation and infiltration of the nasal mucosa by T lymphocytes and eosinophils. The immediate-phase response is mediated by a range of inflammatory mediators (such as histamine, leukotrienes and prostaglandins), resulting in vasodilatation, oedema, mucus secretion, itching and sneezing. Individuals who experience a late-phase response have further nasal symptoms 4–24 h after the initial challenge with allergen. Results of nasal biopsy studies indicate that the late-phase allergic response involves T-lymphocyte activation, production of TH₂-type cytokines and tissue eosinophilia. Corticosteroids potently inhibit T-lymphocyte responses, and clinical studies in subjects with allergic rhinitis have demonstrated that they are extremely effective in blocking both early- and late-phase allergic reactions. Topical aqueous triamcinolone acetonide nasal spray represents a novel formulation of a topical corticosteroid for the treatment of allergic rhinitis. Data from controlled clinical studies indicate that it is effective in treating seasonal and perennial disease, is well tolerated, does not suppress adrenocortical function, is odourless, and can be administered as a once-daily dose.     

Acute urticaria[corrected]-like lesions in allergen-unexposed cutaneous tissues in a mouse model of late allergic rhinitis

The mechanisms of distant manifestation after a local allergic reaction are largely unknown. This study examined the development of cutaneous lesions in a mouse model of late allergic rhinitis (LAR). BALB/c mice were sensitized by ovalbumin (OVA) intraperitoneally two times (on days 0 and 10) and challenged by OVA intranasally on day 14. Four days after OVA challenge, nasal and cutaneous lesions including helper T (Th) responses, expression of adhesion molecules and presence of OVA and IgE were examined, and compared with unsensitized and unchallenged (control) mice. Compared with the control group, the LAR group developed LAR characterized by infiltration of lymphocytes and eosinophils, increased IgE values and increased productions of IL-4 and IL-5, but not IFN-gamma. A dominant infiltration of eosinophils and increase in mast cells, attachment of eosinophils to endothelium, intense expression of VCAM-1 on endothelium in venules and VLA-4 expression on eosinophils and mast cells were recognized in the cutaneous tissues. There were no differences in the expression of ICAM-1 on vascular endothelium and LFA-1 on infiltrated leucocytes between the two groups. CLA expression on lymphocytes was not detected, and the binding of OVA and IgE on mast cells and eosinophils was found in the cutaneous lesions in the LAR group, but not in the control group. This study suggests that acute urticaria[corrected]-like lesions in OVA-unexposed cutaneous tissues may be induced by immediate allergic reaction due to the systemic development of Th2-type response in a mouse model of LAR.     

IFATS collection: Immunomodulatory effects of adipose tissue-derived stem cells in an allergic rhinitis mouse model

Adipose tissue-derived stem cells (ASCs) exhibit immunosuppressive effects in allogeneic transplantation. However, there is no report that evaluates the in vivo immune-modulating effect of ASCs in an experimental allergic rhinitis (AR) model. We investigated whether ASCs migrate to the nasal mucosa in an AR mouse model and evaluated the immune-modulating effect of ASCs in the AR mouse model. Cultured ASCs (2 x 10(6)) were injected i.v. before the first allergen challenge in the AR mouse model. Migration of ASCs to the nasal mucosa was evaluated by immunofluorescence. The immunomodulatory effects of ASCs were evaluated by nasal symptoms, histology, serum ovalbumin (OVA)-specific antibody, and the cytokine profile of the spleen. ASCs migrated to the nasal mucosa in the AR mouse model. ASCs significantly reduced allergic symptoms and inhibited eosinophilic inflammation in the nasal mucosa. ASCs significantly decreased the serum allergen-specific IgE level and the IgG(1)/IgG(2a) ratio and significantly increased the IgG(2a) level in the AR mouse model. ASCs inhibited interleukin (IL)-4 and IL-5 production from OVA-incubated splenocytes, but enhanced interferon-gamma production. In conclusion, ASCs can migrate to the nasal mucosa in the AR mouse model and inhibit eosinophilic inflammation partly via shifting to a T-helper 1 (Th1) from a Th2 immune response to allergens.     

TNF-alpha contributes to the development of allergic rhinitis in mice

BACKGROUND: Allergic rhinitis is an inflammation involving T(H)2-type cytokine production, with pathologic eosinophil infiltration in the nasal mucosa. Although TNF-alpha is thought to be a pro-inflammatory cytokine, the relationship between TNF-alpha and allergic rhinitis has not been clarified. OBJECTIVES: The role of TNF-alpha in a murine model of ovalbumin (OVA)-sensitized allergic rhinitis was investigated by using mice deficient in the gene encoding TNF-alpha (TNF-alpha(-/-) mice). METHODS: Both wild-type (TNF-alpha(+/+)) and TNF-alpha(-/-) mice were sensitized with OVA by means of intraperitoneal injection. They were then challenged with intranasal OVA, and various allergic responses were assessed. RESULTS: The production of OVA-specific IgE in the serum (P <.05) and the frequency of sneezes (P <.05) and nasal rubs (P <.05) decreased significantly in TNF-alpha(-/-) mice after OVA sensitization compared with that in TNF-alpha(+/+) mice (P <.05). The mRNA expression of IL-4, IL-10, and eotaxin in nasal mucosa in TNF-alpha(-/-) mice was also significantly suppressed compared with that in TNF-alpha(+/+) mice after OVA sensitization (P <.05). Furthermore, the expression of both endothelial-leukocyte adhesion molecule 1 and vascular cell adhesion molecule 1 mRNA in the nasal mucosa was significantly suppressed (P <.05), although intercellular adhesion molecule 1 mRNA expression did not decrease significantly in TNF-alpha(-/-) mice compared with that in TNF-alpha(+/+) mice after OVA sensitization. In addition, the effect of TNF-alpha on endothelial-leukocyte adhesion molecule 1 and vascular cell adhesion molecule 1 expression by means of Western blot analysis was compatible with the mRNA results. Pathologically, eosinophil infiltration in nasal mucosa was significantly restricted in TNF-alpha(-/-) mice compared with in TNF-alpha(+/+) mice after OVA sensitization (P <.05). CONCLUSION: TNF-alpha is necessary for antigen-specific IgE production and for the induction of T(H)2-type cytokines and chemokines. Furthermore, TNF-alpha might be important for the expression of adhesion molecules to recruit eosinophils to the allergic inflammatory site. We conclude that the lack of TNF-alpha inhibited the development of allergic rhinitis.     

Fluticasone propionate aqueous nasal spray reduces inflammatory cells in unchallenged allergic nasal mucosa: effects of single allergen challenge

BACKGROUND: Topical corticosteroid therapy reduces symptoms and nasal mucosal inflammatory cells in patients with allergic rhinitis. Usually patients are advised to start their medication (1 week) before the beginning of the pollen season. The effect of pretreatment with a topical corticosteroid on unchallenged nasal mucosa is not well documented. OBJECTIVES: The purpose of this study was to investigate, in a double-blind, placebo-controlled study, the effect of 6 weeks' pretreatment with 200 microg twice daily fluticasone propionate on nasal symptoms and inflammatory cell numbers after nasal allergen provocation in patients with seasonal allergic rhinitis. METHODS: Nineteen patients with grass pollen-induced allergic rhinitis were treated for a 6-week period out of the grass pollen season. After completing the treatment period, patients were challenged with grass pollen. Nasal mucosal biopsy specimens were taken 5 times in every patient. In nasal mucosa changes in numbers of T cells, B cells, mast cells, eosinophils, macrophages, and Langerhans' cells were investigated. RESULTS: After 4 weeks of treatment but before allergen provocation, significantly fewer epithelial Langerhans' cells, macrophages, mast cells, T cells, and eosinophils were found in the fluticasone propionate group compared with those found in the placebo group. In the lamina propria significantly fewer Langerhans' cells and eosinophils were found in the fluticasone propionate group. Cell influx in nasal mucosa after allergen provocation was significantly inhibited in the fluticasone propionate group compared with that in the placebo group for epithelial Langerhans' cells, mast cells, macrophages, and T cells and for lamina propria eosinophils, mast cells, Langerhans' cells, macrophages, and T cells. CONCLUSIONS: Fluticasone propionate is effective in reducing early- and late-phase nasal symptoms. Topical corticosteroid treatment reduces inflammatory cells in unchallenged nasal mucosa.     

Expression and Roles of MMP-2, MMP-9, MMP-13, TIMP-1, and TIMP-2 in Allergic Nasal Mucosa

Purpose

Allergic rhinitis (AR) and asthma share many characteristics, but structural changes are observed far less often in AR. Matrix metalloproteinases (MMPs) constitute a family of Zn-dependent endopeptidases that can decompose the extracellular matrix and basement membrane, and regulate cell infiltration. We analyzed the expression of MMPs and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs), in allergic nasal mucosa after nasal allergen challenge (NAC) and determined their relationship to inflammatory cells.

Methods

Nasal mucosa specimens were obtained at surgery performed for hypertrophied turbinates. We performed NAC with house dust mite (HDM) allergen disks and control disks, and took biopsies at 30 minutes, 6 hours, and 12 hours after NAC. Cells expressing MMP-2, MMP-9, MMP-13, TIMP-1, and TIMP-2, as well as eosinophils and mast cells, were analyzed immunohistochemically. The MMPs and TIMPs in allergic nasal mucosa were quantified using enzyme-linked immunosorbent assays.

Results

At 30 minutes post-NAC, HDM-exposed nasal mucosa exhibited significantly more MMP-2+, MMP-9+, MMP-13+, TIMP-1+, and TIMP-2+ cells compared with control mucosa, and the numbers of MMP-9+ and TIMP-1+ cells correlated strongly with the number of mast cells. At 6 hours post-NAC, the numbers of MMP+ and TIMP+ cells did not differ significantly between HDM-exposed mucosa and control mucosa, but the ratios of MMP+ cells to TIMP+ cells were higher in HDM-exposed mucosa. At 12 hours post-NAC, the number of MMP-13+ cells tended to be higher in HDM-exposed mucosa and was strongly correlated with the number of eosinophils. Quantitatively, the levels of MMP-2 and MMP-13 were significantly higher than the MMP-9 level, and the TIMP-2 level was significantly higher than the TIMP-1 level in allergic nasal mucosa.

Conclusions

We demonstrated increased expression of MMP-2, MMP-9, and MMP-13 in allergic nasal mucosa, high MMPs-to-TIMP-1 ratios, and a strong correlation between MMP-9 and mast cells and between MMP-13 and eosinophils. The imbalance between MMPs and TIMPs may contribute to the migration of inflammatory cells such as eosinophils and mast cells to the nasal mucosa of AR patients, suggesting a possible active role of MMPs in AR.     

TNF α is localized to nasal mucosal mast cells and is released in acute allergic rhinitis

Allergic mucosal inflammation is characterized by tissue infiltration with eosinophils, and associated activation of mast cells and T lymphocytes. Tumour necrosis factor (TNF) alpha/cachectin is a candidate cytokine relevant to the pathogenesis of these events through its capacity to upregulate the expression of endothelial cell adhesion molecules, mediate granulocyte chemoattraction, and activate eosinophils, mast cells and T cells. To investigate the presence and localization of TNF α in the nasal mucosa in allergic rhinitis, nasal biopsies from perennial rhinitic (n=13) and non-rhinitic volunteers (n=11) were embedded in glycol methacrylate and immunostained with a monoclonal antibody directed against TNF α, and adjacent 2μm sections stained for tryptase, CD3 and eosinophil cationic protein. This identified positive immunostaining for TNF α in the submucosa of both the rhinitic and normal subjects (median cell counts 13 and 23 cells/mm² respectively, P=0.24) with cellular localization to mast cells but not to T-lymphocytes or eosinophils. In a subsequent study of seven atopic subjects, nasal allergen challenge produced increases in lavage levels of histamine and albumin, which was associated with significant release of TNF α as early as 2 min post-allergen when compared with the saline control day (P=0.5). This difference was also apparent when studying the area under the curve both at 30 and 60 min post-challenge t-test (P=0.015 and 0.02 respectively). These findings which both locate immunoreactive TNF α to nasal mast cells and identify its release following in vivo exposure to allergen, provide evidence for mast cells as an important source of this cytokine in patients with allergic rhinitis.