Biomedical Laboratory, Division of Biomedical Research, Kitasato Institute Medical Center Hospital, Kitasato University, Saitama, Japan.
Int Immunopharmacol. 2011 Feb;11(2):199-203. doi: 10.1016/j.intimp.2010.11.019. Epub 2010 Nov 21.
Host-defense mechanisms against influenza virus (IFV) infection involve both innate and acquired immunities. Among other components, secretory immunoglobulin A (SIgA) in the airway mucosa plays a particularly pivotal role in preventing IFV infection. Among 150 strains of lactic acid bacteria, Lactobacillus pentosus strain b240 (b240) has the highest IgA-inducing potency in mouse Peyer's patch cells. We previously reported a practical new finding that oral ingestion of nonviable heat-killed b240 elevates salivary IgA secretion in humans. The present study aimed to determine if nonviable b240 can prevent IFV infection in mice. In a BALB/c mouse model infected with lethal levels of IFV A/PR8/34 (H1N1), oral administration of b240 for 3 weeks by gavage prior to IFV infection significantly prolonged the survival period. For IFV infection at nonlethal levels, the infectious titers of IFV in the lungs 7 days after infection were significantly reduced after similar b240 administration. Both anti-IFV IgA and immunoglobulin G titers in bronchoalveolar lavage fluid and plasma on day 7 were significantly higher in the b240-treated group than the control group. The augmentation of the anti-IFV immune response by b240 application was preliminarily confirmed by the elevated production of IFV-driven T-cell factors during mixed lymphocyte reactions with b240-primed splenocytes. These results suggest that oral nonviable heat-killed b240 intake can facilitate protection against IFV infection.
宿主防御机制对抗流感病毒（IFV）感染既包括先天免疫，也包括获得性免疫。在其他成分中，气道黏膜中的分泌型免疫球蛋白 A（SIgA）在预防 IFV 感染中起着特别关键的作用。在 150 株乳酸菌中，戊糖片球菌 b240 株（b240）在小鼠派伊尔斑细胞中具有最高的 IgA 诱导效力。我们之前报道了一个实用的新发现，即口服摄入非活性热灭活的 b240 可提高人类唾液中的 IgA 分泌。本研究旨在确定非活性 b240 是否可以预防小鼠 IFV 感染。在感染致死剂量 IFV A/PR8/34（H1N1）的 BALB/c 小鼠模型中，在 IFV 感染前通过灌胃口服 b240 3 周可显著延长存活期。对于非致死水平的 IFV 感染，在感染后 7 天，感染的 IFV 传染滴度在类似 b240 给药后显著降低。在 b240 处理组中，第 7 天支气管肺泡灌洗液和血浆中的抗 IFV IgA 和免疫球蛋白 G 滴度均明显高于对照组。b240 应用增强抗 IFV 免疫反应的初步确证是通过与 b240 预刺激的脾细胞进行混合淋巴细胞反应时 IFV 驱动的 T 细胞因子的升高来实现的。这些结果表明，口服非活性热灭活的 b240 摄入可以促进对 IFV 感染的保护。
