生命早期短双歧杆菌干预对变应性鼻炎小鼠的免疫调节作用

Immunomodulatory Effect of Bifidobacterium Breve Intervention in Early Life on Allergic Rhinitis in BALB/c Mice.

目的探讨生命早期短双歧杆菌(B.breve)干预对卵清蛋白(OVA)诱导变应性鼻炎(AR)小鼠模型的免疫调节作用。方法24只新生BALB/c雌性小鼠随机分为A组(模型组)、B组(空白组)及C组(B.breve组),每组8只。C组小鼠从出生后第1天即开始给予口服B.breve干预,每日1次,连续8周。随即通过OVA腹腔注射和鼻部滴注建立AR模型。A、B组小鼠均给予生理盐水口服干预,A组采用OVA进行腹腔注射及鼻腔滴注建立AR模型,B组小鼠予以生理盐水腹腔注射及鼻部激发。观察末次鼻部激发后10 min内小鼠喷嚏及抓鼻次数,采用Luminex及ELISA检测各组血清IL-4、IL-10、IFN-γ和OVA特异性IgE(OVA-SIgE)水平,采用流式细胞术检测脾细胞悬液中CD4+CD25+Foxp3+Treg细胞的比例。结果模型组血清OVA-SIgE水平较空白组显著升高(P<0.001),B.breve组血清OVA-SIgE水平较模型组降低,差异统计学意义(P<0.001)。末次鼻部激发后B.breve组抓鼻及喷嚏次数较模型组显著减少(P<0.001)。B.breve组血清IL-4和IL-10水平较模型组降低,差异有统计学意义(P=0.03、P<0.001)。B.breve组脾细胞悬液中CD4+CD25+Foxp3+Treg细胞的比例较模型组显著升高(P<0.001),但两组间血清IFN-γ水平差异无统计学意义(P=0.276)。结论生命早期B.breve口服干预可以有效抑制小鼠后期变应性鼻炎症状,这一作用可能是通过抑制Th2细胞反应及增强CD4+CD25+Treg细胞功能实现的。

Objective The aim of this study was to investigate the immunomodulatory effects of Bifidobacterium Breve(B.breve)intervention in early life on ovalbumin-induced allergic rhinitis(AR).Methods A total of twenty-four newborn BALB/c mice were randomly divided into the positive control group,the negative control group and the B.breve intervention group(n=8).Lively lyophilized B.breve was orally administered for female BALB/c mice in the B.breve intervention group once daily for 8 consecutive weeks.Mice of the positive and negative control group received saline orally for 8 weeks.After that,intraperitoneal injection and nasal drip with OVA were performed to obtain experimental AR in the positive control group and the B.breve intervention group.Saline was used instead of OVA for the negative control group.Nasal rubbing and sneezing were quantified after the final challenge before the sacrifice of mice.The level of serum OVA-specific IgE was measured by ELISA.The percentages of CD4+CD25+Foxp3+regulatory T(Treg)cells in the spleen were measured by flow cytometry.Interleukin(IL)-4,IL-10 and interferon(IFN)-γlevels in serum were measured by Luminex kits.Results The serum OVA-SIgE level of the positive control group was significantly increased compared to that of the negative control group(P<0.001),while that of the B.breve intervention group was significantly reduced compared to that of the positive control group(P<0.001).Nasal rubbing(P<0.001)and sneezing(P<0.001)were significantly decreased compared to that of the positive control group after the final challenge.Meanwhile,the serum level of IL-10(P=0.03)and IL-4(P<0.001)decreased significantly in the B.breve intervention group compared to that of the positive group.The percentage of CD4+CD25+Foxp3+T lymphocytes in the B.breve intervention group was significantly higher than that in the positive control group(P<0.001).There was no significant difference in the serum level of IFN-γbetween the positive control group and the B.breve intervention group(P=0.276).Conclusion Early intervention of probiotics on allergic rhinitis mice model exerts its anti-allergic effects by inhibiting Th2 immune response and inducing the activity of CD4+CD25+Foxp3+Tregs without affecting Th1 response.