Department of East-West Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Yongin 446-701, Korea.
J Microbiol Biotechnol. 2011 Nov;21(11):1174-8. doi: 10.4014/jmb.1105.05026.
Exopolysaccharides (EPSs) are microbial polysaccharides that are released outside of the bacterial cell wall. There have been few studies on EPS-producing lactic acid bacteria that can enhance macrophage activity and the underlying signaling mechanism for cytokine expression. In the current study, EPS-overproducing Lactobacillus (L.) paracasei KB28 was isolated from kimchi and cultivated in conditioned media containing glucose, sucrose, and lactose. The whole bacterial cells were obtained with their EPS being attached, and the cytokine-inducing activities of these cells were investigated. Gas chromatography analysis showed the presence of glucose, galactose, mannose, xylose, arabinose, and rhamnose in EPS composition. EPS-producing L. paracasei KB28 induced the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-12 in mouse macrophages. This strain also caused the degradation of IκBα and phosphorylation of the major MAPKs: Jun N-terminal kinase (JNK), p38, and extracellular signal-regulated kinase (ERK)1/2. The use of pharmacological inhibitors showed that different signaling pathways were involved in the induction of TNF-α, IL-6 and IL-12 by L. paracasei KB28. Our results provide information for a better understanding of molecular mechanisms of the immunomodulatory effect of food-derived EPS-producing lactic acid bacteria.
胞外多糖 (EPSs) 是一种释放到细菌细胞壁外的微生物多糖。目前，关于能够增强巨噬细胞活性和细胞因子表达的潜在信号机制的产 EPS 乳酸菌的研究较少。在本研究中，从泡菜中分离出产 EPS 的副干酪乳杆菌 (L.) paracasei KB28，并在含有葡萄糖、蔗糖和乳糖的条件培养基中进行培养。获得附着 EPS 的整个细菌细胞，并研究这些细胞的细胞因子诱导活性。气相色谱分析表明 EPS 组成中存在葡萄糖、半乳糖、甘露糖、木糖、阿拉伯糖和鼠李糖。产 EPS 的副干酪乳杆菌 KB28 诱导小鼠巨噬细胞表达肿瘤坏死因子 (TNF)-α、白细胞介素 (IL)-6 和 IL-12。该菌株还导致 IκBα 降解和主要 MAPKs 的磷酸化：Jun N-末端激酶 (JNK)、p38 和细胞外信号调节激酶 (ERK)1/2。使用药理抑制剂表明，不同的信号通路参与了 L. paracasei KB28 诱导 TNF-α、IL-6 和 IL-12 的表达。我们的结果为更好地了解食品来源的产 EPS 乳酸菌的免疫调节作用的分子机制提供了信息。
