OVA-bound nanoparticles induce OVA-specific IgG1, IgG2a,and IgG2b responses with low IgE synthesis

There is an urgent requirement for a novel vaccine that can stimulate immune responses without unwanted toxicity, including IgE elevation. We examined whether antigen ovalbumin (OVA) conjugated to the surface of nanoparticles (NPs) (OVA-NPs) with average diameter of 110 nm would serve as an immune adjuvant. When BALB/c mice were immunized with OVA-NPs, they developed sufficient levels of OVA-specific IgG1 antibody responses with low levels of IgE synthesis, representing helper T (Th)2-mediated humoral immunity. OVA-specific IgG2a and IgG2b responses (i.e., Th1-mediated immunity) were also induced by secondary immunization with OVA-NPs. As expected, immunization with OVA in alum (OVA-alum) stimulated humoral immune responses, including IgG1 and IgE antibodies, with only low levels of IgG2a/IgG2b antibodies. CD4-positive T cells from mice primed with OVA-NPs produced substantial levels of IL-21 and IL-4, comparable to those from OVA-alum group. The irradiated mice receiving OVA-NPs-primed B cells together with OVA-alum-primed T cells exhibited enhanced anti-OVA IgG2b responses relative to OVA-alum-primed B cells and T cells following stimulation with OVA-NPs. Moreover, when OVA-NPs-primed, but not OVA-alum-primed, B cells were cultured in the presence of anti-CD40 monoclonal antibody, IL-4, and IL-21, or LPS plus TGF-β in vitro, OVA-specific IgG1 or IgG2b antibody responses were elicited, suggesting that immunization with OVA-NPs modulates B cells to generate IgG1 and IgG2b responses. Thus, OVA-NPs might exert their adjuvant action on B cells, and they represent a promising potential vaccine for generating both IgG1 and IgG2a/IgG2b antibody responses with low IgE synthesis.     

Stable dry powder inhaler formulation of tranilast attenuated antigen-evoked airway inflammation in rats

Tranilast (TL) has been clinically used for the treatment of airway inflammatory diseases, although the clinical use of TL is limited because of its poor solubility and systemic side effects. To overcome these drawbacks, a novel respirable powder of TL (CSD/TL-RP) for inhalation therapy was developed using nanocrystal solid dispersion of TL (CSD/TL). Stability study on CSD/TL-RP was carried out with a focus on inhalation performance. Even after 6 months of storage at room temperature, there were no significant morphological changes in micronized particles on the surface of carrier particles as compared with that before storage. Cascade impactor analyses on CSD/TL-RP demonstrated high inhalation performance with emitted dose and fine particle fraction (FPF) of ca. 98% and 60%, respectively. Long-term storage of CSD/TL-RP resulted in only a slight decrease in FPF value (ca. 54%). Inhaled CSD/TL-RP could attenuate antigen-induced inflammatory events in rats, as evidenced by marked reduction of granulocytes in bronchoalveolar lavage fluid and inflammatory biomarkers such as eosinophil peroxidase, myeloperoxidase, and lactate dehydrogenase. These findings were consistent with decreased expression levels of mRNAs for nuclear factor-kappa B and cyclooxygenase-2, typical inflammatory mediators. Given these findings, inhalable TL formulation might be an interesting alternative to oral therapy for the treatment of asthma and other airway inflammatory diseases with sufficient dispersing stability.     

内脏高敏感状态下食管酸灌注诱导的鼠脊髓背角c-Fos基因表达的研究

目的 观察在内脏高敏感状态下,食管酸灌注诱导的大鼠脊髓背角Fos 蛋白表达的表达,初步探索食管内脏感觉过敏在脊髓水平敏感化的分子机制.方法 采用腹腔注射鸡卵清蛋白基础致敏联合食管酸灌注的方法,建立内脏高敏感性-食管化学刺激大鼠模型;采用免疫组织化学方法和显微图像分析技术研究,在生理条件、内脏高敏感状态下进行食管酸灌注时Fos蛋白激活模式的差异.结果 模型组大鼠双侧脊髓背角内有大量的Fos样免疫反应 (FLI) 阳性神经元,集中分布于背角Ⅰ～Ⅱ、Ⅴ～Ⅶ层,其FLI阳性神经元数量和平均光密度值较单纯食管酸灌注组和单纯,OVA(ovalbumin)致敏组明显增加,差异有统计学意义(P＜0.05).单纯酸灌注组和单纯OVA致敏组在背角Ⅰ～Ⅱ、Ⅴ～Ⅵ、Ⅹ层的FLI阳性神经元数量均较生理盐水对照组显著增加,差异有统计学意义(P＜0.01).单纯酸灌注组在背角Ⅰ～Ⅱ层和Ⅲ～Ⅳ层FLI阳性细胞数较单纯OVA致敏组显著增加,差异有统计学意义(P＜0.05).结论 腹腔注射鸡卵清蛋白基础致敏,对食管酸灌注诱导的脊髓背角内Fos蛋白表达有活化作用,c-Fos过度表达的阳性神经元的兴奋性增加和神经可塑性改变,促进了内脏高敏感性在脊髓水平敏感化的形成和维持.     

环孢素A气雾给药对豚鼠气道高反应性和炎症的作用

目的:评价环孢素A气雾给药对豚鼠哮喘模型的药效.方法:用乙酰胆碱(ACh)或组胺诱导抗原攻击后的致敏豚鼠气道阻力PC_(200)、支气管肺泡灌洗液(BALF)和肺组织切片中的嗜酸性粒细胞(EOS)变化观察环孢素A气雾给药后的抗气道高反应性和炎症作用.结果:环孢素A 10 g·L~(-1)、20 g·L~(-1)气雾给药和地塞米松(0.5mg·kg~(-1),ip)增加PC_(200)值,能预防ACh或组胺引起的气道高反应性,环孢素A 5 g·L~(-1)对组胺引起的气道高反应性也有作用,对ACh不显著.环孢素A 10 g·L~(-1)、20 g·L~(-1)气雾给药能明显减少BALF中的EOS浸润.与溶媒组比较,地塞米松0.5mg·kg~(-1)增加了BALF中的中性粒细胞数目,与三组环孢素A比较有显著差异.在肺组织学研究中,环孢素A 20 g·L~(-1)和地塞米松0.5 mg·kg~(-1)可抑制支气管和细支气管上皮和上皮表面结缔组织的EOS浸润.结论:环孢素A气雾吸入给药能明显对抗致敏豚鼠气道高反应性和炎症反应,为其治疗哮喘提供了一个可选择的给药途径.     

Inhibitory effects of cryptoporus polysaccharide on airway constriction, eosinophil release, and chemotaxis in guinea pigs

AIM: To study effects of cryptoporus polysaccharide (CP) on antigen-induced bronchoconstriction, eosinophil peroxidase (EPO) release in vivo, and on platelet activating factor (PAF)-induced eosinophil chemotaxis in vitro in guinea pig. METHODS: The asthma model of guinea pig was formed with ovalbumin (OVA). The changes of lung resistance (RL) and dynamic lung compliance (Cdyn), EPO level in bronchoalveolar lavage fluids (BALF) and eosino- phil migration were determined. RESUL…     

Artificial Tears Inhibit the Development of Experimental Immune-mediated Blepharoconjunctivitis

Purpose To investigate whether treatment with artificial tears inhibits the development of experimental immune-mediated blepharoconjunctivitis (EC).Methods Brown Norway rats were immunized with ovalbumin (OVA) or ragweed (RW) emulsified in complete Freunds adjuvant. Fourteen days after immunization, the rats were challenged with the same antigen (Ag) in eye drops. Treated rats were administered artificial tears by eye drops immediately after, 15min after, or 30min after the Ag challenge. Treatment doses of 2, 4, or 8 drops per eye were evaluated. Twenty-four hours after the Ag challenge, the rats were killed and their eyes were harvested for histological studies.Results Treatment with artificial tears immediately after and 15min after challenge with partially insoluble RW Ag suppressed infiltration of inflammatory cells into the conjunctiva. Inhibition was not observed at any time following challenge with OVA Ag, which is a soluble protein. The treatment dose of artificial tears administered did not affect the extent of inhibition of EC following challenge with either Ag.Conclusions Treatment with artificial tears by eye drops inhibited the development of EC induced by the partially insoluble RW Ag when administered within 15min of the Ag challenge. Jpn J Ophthalmol 2004;48:530–534 © Japanese Ophthalmological Society 2004     

Oral-Antigen Delivery via a Water-in-Oil Emulsion System Modulates the Balance of the Th1/Th2 Type Response in Oral Tolerance

Purpose. To evaluate the ability of a water-in-oil (W/O) emulsion containing ovalbumin (OVA), a model antigen, to induce oral tolerance and to elucidate the mechanism for the induction of oral tolerance by the emulsion system. Methods. A W/O emulsion containing OVA was prepared and evaluated its ability to induce oral tolerance in mice. Also, the Th1/Th2 balance in the mice tolerized was investigated in terms of the ratios of anti-OVA IgG2a titer to anti-OVA IgG1 titer (IgG2a/IgG1 ratios) and cytokine profiles. Results. Anti-OVA total IgG antibody titer of mice administered OVA in saline was approximately 3.5-fold higher than that of the mice administered OVA in W/O emulsion at a dose of 0.1 mg/mouse/day. Similar total IgG responses were observed between the above two at a dose of 1 mg/mouse/day. The IgG2a/IgG1 ratios decreased as the dose of OVA in W/O emulsion, but not in saline, increased at doses of 0, 0.1, and 1 mg/mouse/day. Interferon- secretion of PLN cells from the mice administered OVA in W/O emulsion decreased, whereas their interleukin-4 secretion remained high. Although interferon- secretion for the mice administered OVA in saline decreased, interleukin-4 secretion did not change. Conclusions. The present study suggests that oral delivery of OVA via the W/O emulsion system may more efficiently enhance the induction of Th2-dominated imbalance than that of OVA in saline.     

艾叶油的呼吸系统药理研究-Ⅱ,抗过敏作用

目的：本文研究艾叶油的抗过敏作用。方法：采用致敏豚鼠气管ＳｃｈｕｌｔｚＤａｌｅ 反应,组胺或氨甲酰胆碱引起的豚鼠气管收缩,大鼠被动皮肤过敏,５羟色胺引起的大鼠皮肤毛细血管通透性增强,豚鼠肺组织释放过敏性慢反应物质（ＳＲＳＡ） ,ＳＲＳＡ 收缩豚鼠回肠等试验。结果：艾叶油抑制致敏豚鼠气管ＳｃｈｕｌｔｚＤａｌｅ 反应（ＩＣ５０ ：９８ ．６ｍｇ／Ｌ） ;１００ｍｇ／Ｌ 明显降低组胺或氨甲酰胆碱引起的豚鼠气管收缩ｐＤ２ 值;明显抑制大鼠被动皮肤过敏（ＩＤ５０ ：０ ．２２ｇ／ｋｇ） 和５羟色胺引起的大鼠皮肤毛细血管通透性增强反应（ＩＤ５０ ：０ ．５２ｇ／ｋｇ） ;抑制豚鼠肺组织释放ＳＲＳＡ（ＩＣ５０ ：４９ ．７ｍｇ／Ｌ） ;拮抗ＳＲＳＡ 对豚鼠回肠的收缩（ＩＣ５０ ：３４ ．９ｍｇ／Ｌ） 。结论：艾叶油具有抗过敏作用,对呼吸道过敏反应有保护作用,是其治疗支气管哮喘和慢性气管炎作用机制之一