Nanomedicine-mediated prevention of inflammatory monocytes infiltration ameliorate ovalbumin-induced allergic rhinitis in mouse model

Abstract

Th2 immune cells infiltration into nasal mucosa is one of the characters of allergic rhinitis (AR). We aimed to explore whether inhibition of Th2 immune cells infiltration would attenuate AR progression. AR mouse model was established by i.p. injection of ovalbumin (OVA). The infiltrated immune cells into nasal lavage fluid were detected by flow cytometry. Cytokine concentration in serum was determined by ELISA. AR mice symptoms were indicated by the number of sneezing and nasal rubbing events. In AR mice, CCL2 expression levels and CD45⁺CD11b⁺Ly6C^hi inflammatory monocytes cells significantly increased as compared with control mice. CCL2 siRNA encapsulated nanoparticles (NP_siCCL2) prevent CCL2 expression and inflammatory monocytes infiltration in AR mice. NP_siCCL2 treatment dramatically decreased the number of sneezing and nasal rubbing events in AR mice. Moreover, NP_siCCL2 treatment attenuated serum OVA-specific IgE, OVA-specific IgG1 and histamine levels. Mechanically, NP_siCCL2 treatment attenuates AR symptoms via inhibiting Th2 cytokine (IL-4, IL-5 and IL-13) production. Nanomedicine-mediated prevention of inflammatory monocytes infiltration ameliorates ovalbumin-induced allergic rhinitis in mouse model.     

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.     

Ovalbumin-specific IgE modulates ovalbumin-specific T-cell response after repetitive oral antigen administration

BACKGROUND: Some patients outgrow their food allergies even though their serum antigen-specific IgE levels remain high. OBJECTIVE: To elucidate the role of T cells in outgrowing food allergies in the presence of antigen-specific IgE, we tracked antigen-specific T-cell responses after oral antigen administration. METHODS: Ovalbumin (OVA)-specific T-cell receptor (TCR) and OVA-specific IgE transgenic (Tg) mice (OVA-TCR/IgE-Tg) and OVA-specific TCR Tg (OVA-TCR-Tg) mice were fed with high doses of OVA or PBS every other day. After 7 administrations, OVA-specific proliferation and cytokine production of mononuclear cells of the spleen, mesenteric lymph nodes, and Peyer's patches and the number of splenic CD4 + CD25 + T cells were analyzed. RESULTS: Without OVA administration, the splenocytes from OVA-TCR/IgE-Tg mice exhibited a higher proliferative response and produced more IL-4 and IL-10 and less IFN-gamma than those from OVA-TCR-Tg mice. The proliferative responses of the splenocytes from either OVA-TCR/IgE-Tg mice or OVA-TCR-Tg mice fed with OVA were significantly reduced compared with those from PBS-fed mice. The number of OVA-specific TCR + T cells decreased in the spleen from OVA-fed mice, whereas the number of CD4 + CD25 + T cells increased. The suppressed proliferation of splenocytes of OVA-fed mice was partially resumed by neutralization of TGF-beta1, but not of IL-10. CONCLUSION: The presence of OVA-specific IgE modulated the OVA-specific responses of the splenocytes. Irrespective of the presence of OVA-specific IgE, repetitive oral administration of OVA induced tolerance, which seems to be composed of clonal deletion/anergy and TGF-beta1-mediated active suppression.     

Effect of Brazilian propolis on sneezing and nasal rubbing in experimental allergic rhinitis of mice

We studied the effect of Brazilian propolis on sneezing and nasal rubbing in experimental allergic rhinitis of mice. A single administration of propolis caused no significant effect on both antigen-induced nasal rubbing and sneezing at a dose of 1000?mg/kg, but a significant inhibition was observed after repeated administration for 2 weeks at this dose. Propolis caused no significant inhibitory effect on the production of total IgE level after repeated administration of 1000?mg/kg. The drug also caused no significant inhibition of histamine-induced nasal rubbing and sneezing at a dose of 1000?mg/kg. On the other hand, propolis significantly inhibited histamine release from rat mast cells induced by antigen and compound 48/80 at a concentration of more than 10 μg/ml. These results clearly demonstrated that propolis may be effective in the relief of symptoms of allergic rhinitis through inhibition of histamine release.     

Helper CD4+ T cells for IgE response to a dietary antigen develop in the liver

BACKGROUND: Although T-cell responses to food antigens are normally inhibited either by deletion, active suppression, or both of antigen-specific T cells, T helper cells for IgE response to a food antigen still develop by unknown mechanisms in a genetically susceptible host. OBJECTIVE: We determined the site at which those IgE helper T cells develop. METHODS: We administered ovalbumin (OVA) orally to DO11.10 mice and studied CD4+ T cells in Peyer's patches, the spleen, and the liver. Helper activity for IgE response was assessed by adoptively transferring those CD4+ T cells to naive BALB/c mice, followed by systemic immunization with OVA. RESULTS: OVA-specific CD4+ T cells were deleted by cell death in the liver and Peyer's patches of DO11.10 mice fed OVA. OVA-specific CD4+ T cells that survived apoptosis in the liver expressed Fas ligand and secreted IL-4, IL-10, and transforming growth factor beta(1). CD4+ T cells producing IFN-gamma were deleted in the liver by repeated feeding of OVA. On transfer of CD4+ T cells to naive mice and systemic immunization with OVA, a marked increase in OVA-specific IgE response developed only in the mice that received hepatic CD4+ T cells from OVA-fed mice, the effect of which was not observed in the recipients of hepatic CD4+ T cells deficient in IL-4. In addition, significant suppression of delayed-type hypersensitivity and IgG(1)/IgG(2a) responses to OVA was observed in the recipients of hepatic CD4+ T cells, and this suppression required Fas/Fas ligand interaction. CONCLUSION: Together, these results suggested that a food antigen might negatively select helper T cells for IgE response to the antigen by preferential deletion of T(H)1 cells in the liver.     

SIRT1 attenuates murine allergic rhinitis by downregulated HMGB 1/TLR4 pathway

Conventional allergic rhinitis (AR) treatments have limitations due to the lack of safety and complete cure strategy. We evaluated the effects of silent information regulator 1 (SIRT1), a multifunctional molecule involved in a variety of inflammatory pathways, on murine AR model. Ovalbumin (OVA)‐induced murine model was constructed, and recombinant SIRT1 was administered into the nostril continuously. The expression of SIRT1 was measured at mRNA and protein levels, and the allergic symptoms were evaluated. Protein levels of OVA‐specific IgE, leukotriene C4 (LTC4), eosinophil cation protein (ECP), prostaglandin D2 (PGD2), as well as different inflammatory cytokine mediators in the serum and nasal lavage fluid (NLF), were assessed by ELISA. The effects of SIRT1 on human primary nasal epithelial cells challenged with tumour necrosis factor (TNF)‐α were also evaluated by investigating the HMGB1/TLR4 signalling pathway. Administration of SIRT1 significantly alleviated OVA‐induced AR symptoms with lower numbers of sneezing and nasal rubbing events, decreased levels of OVA‐specific IgE, LTC4, ECP, PGD2, less inflammatory cells and downregulated levels of Th2 type cytokines. SIRT1 also reduced the genes of HMGB1/TLR4 signalling pathway in the murine model and cultured human nasal epithelial cells. Expression of SIRT1 is impaired in OVA‐induced AR model. The administration of SIRT1 alleviates the allergic symptoms of mice, regulates the production of pro‐inflammatory mediators predominantly produced by Th2 cells in AR and attenuates expressions of proteins relevant to HMGB1/TLR4 signalling pathway. All the results showed that SIRT1 is promising as a therapeutic agent of AR.     

Toll样受体9配体CpG-ODN鼻内应用对变应性联合气道疾病炎性反应的影响

目的:探讨免疫刺激序列Cp G寡聚脱氧核苷酸(Cp G-ODN)鼻内应用与皮下注射对变应性联合气道疾病(ACAD)模型小鼠下气道炎性反应的影响。方法:30只清洁级雌性BALB/c鼠随机分为正常对照组(control组)、变应性鼻炎组(AR组)、变应性联合气道疾病组(ACAD组)、变应性联合气道疾病Cp G-ODN鼻内滴入组(Cp G i.n.组)和变应性联合气道疾病Cp G-ODN皮下注射组(Cp G i.d.组)。实验组动物依次进行腹腔卵白蛋白(OVA)和氢氧化铝凝胶基础致敏和3次鼻腔激发,此后OVA或生理盐水(NS)雾化气道激发,正常对照组则给予NS。Cp G i.n.组和Cp G i.d.组分别给予10.0μg Cp G-ODN滴鼻和皮下注射,其它组给予NS滴鼻或皮下注射。观察Cp GODN干预后对鼻腔及下气道病理变化及评分,并对支气管肺泡灌洗液(BALF)行白细胞分类及嗜酸性粒细胞计数,ELISA法测定BALF和脾脏中细胞因子IL-4、IL-5、IL-13和IFN-γ,以及血清OVA特异性Ig E。结果:炎症细胞浸润评分示ACAD组小鼠肺部的病理改变程度高于control组和AR组(P0.01);Cp G i.n.组炎症评分较ACAD组下降,差异有统计学显著性(P0.05),而Cp G i.d.组炎症评分较ACAD组略有下降,但差异无统计学意义。Cp G i.n.组BALF中的白细胞总数、EOS绝对值计数、EOS百分比、BALF和脾脏淋巴细胞上清液中Th2细胞因子较ACAD组降低,差异具有统计学显著性(P0.01)。Cp G i.d.组上述指标略低于ACAD组,但差异无统计学显著性。Cp G i.n.组血清的OVA特异性Ig E较ACAD组下降,差异有统计学显著性(P0.05),而Cp G i.d.组与ACAD组比较有所下降,但差异无统计学显著性。结论:Cp G-ODN可通过抑制变应性鼻炎而抑制变应性联合气道疾病小鼠的下气道炎性反应,鼻内应用可能较皮下注射更有效。     

Topical CTLA4-Ig suppresses ongoing mucosal immune response in presensitized murine model of allergic rhinitis.

Allergic rhinitis is thought to be mediated by CD4+ T cells producing Th2-associated cytokines. Optimal Ag-specific T-cell activation requires the engagement of T-cell receptor with antigen (Ag) in the context of MHC, and the engagement of appropriate costimulatory molecules. One of the most well-characterized costimulatory pathways is the interaction of B7/CD28-CTLA4 molecules. Recent studies have suggested that the costimulatory pathway may influence the development of Th2 immune responses. The objective of this study was the examination of the role of B7/CD28-CTLA4 costimulatory pathway in the pathogenesis of ovalbumin (OVA)-induced immune response in presensitized murine model of allergic rhinitis. Systemically presensitized BALB/c mice significantly developed Ag-induced early phase nasal symptoms, nasal hyperresponsiveness to histamine, nasal eosinophilia, serum levels of OVA- specific IgE and Th2-associated cytokines following repeated topical Ag challenges. Topical administration of CTLA4-Ig during nasal challenges inhibited Ag-induced nasal symptoms and histamine hyperresponsiveness. We also found a significant reduction in nasal lavage eosinophilia and serum levels of OVA-specific IgE. Furthermore, CTLA4-Ig treatment significantly decreased interleukin (IL)-4 content in nasal tissue, while there was no significant change in IL-5 or IFN-gamma levels. These results suggest that B7/CD28-CTLA4 costimulatory pathway mediates the development of ongoing Th2 immune responses and plays a major role in regulating allergic disease, such as allergic rhinitis.     

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.     

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.     

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。     

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.     

Petroleum extract of Farfarae Flos alleviates nasal symptoms by regulating the Th1-Th2 cytokine balance in a mouse model of Allergic Rhinitis

Farfarae Flos is a traditional Chinese medicine that has long been used to treat allergies. In this study, we aimed to investigate the effect of a petroleum extract of Farfarae Flos (PEFF) in a mouse model of allergic rhinitis (AR) and to explore the underlying molecular mechanisms of action. An animal model of AR was established by sensitization and challenge of BALB/c mice with ovalbumin (OVA). PEFF was administered intranasally and AR nasal symptoms were assessed on a semi-quantitative scale according to the frequencies of nose rubbing and sneezing and the degree of rhinorrhea. The mechanism of action of PEFF was evaluated by histological analysis of nasal mucosa architecture and inflammatory status; ELISA-based quantification of serum OVA-specific IgE, interferon-γ (IFN-γ), and interleukin-4 (IL-4) concentrations; and immunohistochemical and western blot analysis of T-bet and GATA3 protein expression in nasal mucosa and spleen tissues. The results showed intranasal administration of PEFF alleviated AR symptom scores and reduced both the infiltration of inflammatory cells and tissue damage in the nasal mucosa. PEFF significantly decreased serum concentrations of OVA-specific IgE (P<0.01) and IL-4 (P<0.05) and significantly increased IFN-γ (P<0.01). PEFF also upregulated the expression of T-bet protein (P<0.05) but downregulated GATA3 protein (P<0.05) in nasal mucosa and spleen tissues. In conclusion, PEFF effectively reduces AR nasal symptoms and serum IgE levels in a mouse model and may act by correcting the imbalance between Th1 and Th2 responses.     

Adjuvant effects of salidroside from Rhodiola rosea L. on the immune responses to ovalbumin in mice

Salidroside, a major component of Rhodiola rosea L., was evaluated for its adjuvant effects on the immune responses in mice by ovalbumin (OVA) stimulation. BALB/c mice were immunized subcutaneously with OVA 100 μg or OVA 100 μg dissolved in saline containing alum (100 μg) or salidroside (12.5, 25, or 50 μg) on Days 1 and 15. Two weeks later (Day 28), blood samples were collected to analyze OVA-specific IgG, IgG1, and IgG2b antibodies. Meanwhile, splenocytes were harvested to assess lymphocyte proliferation, cytokines (IL-2, IL-4, and IFN-γ) production, and CD4(+), CD8(+) lymphocyte subsets. The results indicated that co-administration of salidroside with OVA significantly enhanced the ConA-, LPS-, and OVA-induced splenocyte proliferation, produced more IL-2, IL-4, IFN-γ, and IgG, IgG1, and IgG2b antibody levels, and increased the percentage of CD4(+), CD8(+) lymphocyte subsets than OVA alone. Thus, salidroside possess immunological adjuvant activity by regulating humoral and cellular immune responses in mice.     

Inhibition of allergic responses by CD40 gene silencing

Background:  Gene silencing using small interfering RNA (siRNA) is a potent method of specifically knocking down molecular targets. Small interfering RNA is therapeutically promising, however, treatment of allergic diseases with siRNA has not been explored in vivo . The aim of this study was to evaluate therapeutic effects of CD40 siRNA on inhibition of allergic responses.
Methods:  Mice sensitized with ovalbumin (OVA) and alum were treated with CD40 siRNA, scrambled siRNA, or phosphate buffer saline (PBS) alone, and then challenged intranasally with OVA.
Results:  A significant reduction in nasal allergic symptoms was observed in the CD40 siRNA treated OVA-allergic mice compared to the controls of scrambled siRNA and PBS alone, which is correlated with the decrease of local eosinophil accumulation. CD40 siRNA treatment knocked down CD40 expression on dendritic cells (DCs) in vivo and impaired their antigen presenting function. Treatment with CD40 siRNA resulted in inhibition of OVA-specific T cell response and decrease of interleukin-4 (IL-4), IL-5, and interferon-γ production from T cells stimulated with OVA. Administration of CD40 siRNA also suppressed CD40 expression on B cells, resulting in down-regulation of OVA-specific immunoglobulin E (IgE), IgG1, and IgG2a levels. Additionally, increased regulatory T cells were observed in the CD40 siRNA treated mice.
Conclusions:  The present study demonstrates a novel therapeutic use for siRNA in allergy. CD40 siRNA attenuated allergy through inhibition of DC and B cell functions and generation of regulatory T (Treg) cells.     

IgE-dependent enhancement of Th2 cell-mediated allergic inflammation in the airways

T helper 2 (Th2) cell-derived cytokines, including interleukin (IL)-4, IL-5 and IL-13, play important roles in causing allergic airway inflammation. In contrast to Th2 cells, however, the role of IgE and mast cells in inducing allergic airway inflammation is not understood fully. In the present study, we addressed this point using transgenic mice expressing trinitrophenyl (TNP)-specific IgE (TNP-IgE mice), which enable us to investigate the role of IgE without the influence of antigen-specific T cell activation and other immunoglobulins. When the corresponding antigen, TNP-BSA, was administered intranasally to TNP-IgE mice, a large number of CD4+ T cells were recruited into the airways. In contrast, TNP-BSA administration did not induce eosinophil recruitment into the airways or airway hyperreactivity. Furthermore, when ovalbumin (OVA)-specific Th2 cells were transferred to TNP-IgE mice and the mice were challenged with inhaled OVA, TNP-BSA administration increased OVA-specific T cell recruitment and then enhanced Th2 cell-mediated eosinophil recruitment into the airways. These results indicate that IgE-induced mast cell activation principally induces CD4+ T cell recruitment into the airways and thus plays an important role in enhancing Th2 cell-mediated eosinophilic airway inflammation by recruiting Th2 cells into the site of allergic inflammation.     

Systemic Administration of Olygodeoxynucleotides with CpG Motifs at Priming Phase Reduces Local Th2 Response and Late Allergic Rhinitis in BALB/c Mice

Oligodeoxynucleotides (ODN) with CpG motifs (CpG ODN) induce T helper (Th)1-type reaction. We aimed to evaluate the therapeutic effect of CpG ODN in the development of late allergic rhinitis induced by ovalbumin (OVA), which is one of Th2 diseaes, in BALB/c mice. Effects of a single dose of synthetic CpG-ODN (50 μg) intraperitoneally (i.p.) at the priming phase (on day 0) by OVA on the development of late eosinophilic rhinitis at respiratory areas were compared to the control mice treated with its vehicle (ODN without CpG motifs; 50 μg). Animals were again sensitized by OVA (on day 10) i.p., and 4 days after second sensitization animals were challenged by OVA intranasally (on day 14). Four days after challenge, eosinophilic reactions, nasal lesions and local cytokine values were examined. Compared to the control group, the CpG ODN-administration increased production of OVA-specific Th1 cytokine (interferon-γ) and decreased productions of ovalubmin-specific Th2 cytokines [interleukin (IL)-5 and IL-13] in nasal cavity fluids, supernatants of splenocytes and/or sera. Also, eosinophilia and increased total IgE values were decreased in mice treated with the CpG ODN compared to the control group. Moreover, nasal lesions with infiltration of eosinophils were prominently reduced by the CpG ODN-treatment compared to the control mice. The present study suggests that the systemic administration of CpG ODN at the priming phase may reduce local OVA-specific Th2 responses, resulting in decreased nasal pathology in the late allergic eosinophilic rhinitis. The authors wish it to be known, in their opinion, Toshiharu Hayashi and Keiko Hasegawa contributed equally to this work.