Instituto de Estudios de la Inmunidad Humoral Prof. Dr. R.A. Margni (IDEHU, CONICET-UBA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
Int Arch Allergy Immunol. 2012;157(1):11-20. doi: 10.1159/000324673. Epub 2011 Sep 5.
Allergic diseases are featured by an increased production of IgE due to an imbalance in the immune response towards a Th2 profile. In this work, the ability of Enterococcus faecalis CECT7121 to regulate this Th2-exaggerated response in a murine model of ovalbumin (OVA)-induced allergy was studied.
BALB/c mice intragastrically inoculated with E. faecalis CECT7121 before and during a subcutaneous immunization protocol with OVA were studied in comparison with an immunized control group. The allergen-specific immune response (IgE, IgG, IgG1 and IgG2a) was assessed. The proliferative activity of memory splenocytes and the levels of IL-4, IL-5, IL-13, IL-10, IL-12 and IFN-γ were also determined.
Upon treatment with E. faecalis CECT7121 the following effects were observed: (1) a decrease in specific IgE levels, (2) an increase in anti-OVA IgG2a levels, (3) the levels of anti-OVA IgG and IgG1 remained unaltered, (4) a reduction in the proliferation rate of memory cells, (5) a decrease in the levels of the Th2 cytokines IL-4, IL-5 and IL-13, and (6) the secretion of IL-10, IL-12 and IFN-γ remained unchanged. Moreover, the incubation of human basophils with non-viable E. faecalis CECT7121 together with an allergen preparation induced the release of β-hexosaminidase at levels that were lower than control reactions and similar i.g. the spontaneous release.
In this model, the i.g. administration of E. faecalis CECT7121 hampers the establishment of the OVA-induced allergic immune response, suggesting that this strain could be useful for the treatment of IgE-mediated allergic diseases.
过敏性疾病的特点是由于对 Th2 表型的免疫反应失衡，导致 IgE 产生增加。在这项工作中，研究了粪肠球菌 CECT7121 在卵清蛋白（OVA）诱导过敏的小鼠模型中调节这种 Th2 过度反应的能力。
在皮下免疫 OVA 之前和期间，用粪肠球菌 CECT7121 灌胃接种 BALB/c 小鼠，并与免疫对照组进行比较。评估过敏原特异性免疫反应（IgE、IgG、IgG1 和 IgG2a）。还测定了记忆性脾细胞的增殖活性以及 IL-4、IL-5、IL-13、IL-10、IL-12 和 IFN-γ 的水平。
用粪肠球菌 CECT7121 处理后，观察到以下效果：（1）特异性 IgE 水平降低，（2）抗 OVA IgG2a 水平升高，（3）抗 OVA IgG 和 IgG1 水平保持不变，（4）记忆细胞增殖率降低，（5）Th2 细胞因子 IL-4、IL-5 和 IL-13 水平降低，（6）IL-10、IL-12 和 IFN-γ 的分泌保持不变。此外，与过敏原制剂一起孵育非活性粪肠球菌 CECT7121 可诱导人嗜碱性粒细胞释放β-己糖胺酶，其水平低于对照反应，且与自发释放相似。
在该模型中，粪肠球菌 CECT7121 的口服给药阻碍了 OVA 诱导的过敏免疫反应的建立，表明该菌株可用于治疗 IgE 介导的过敏性疾病。
