Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-0201, USA.
J Anim Sci. 2010 May;88(5):1649-56. doi: 10.2527/jas.2009-2263. Epub 2010 Jan 15.
Previous research evaluated a laboratory strain of Bacillus licheniformis (BL) in a model swine epithelium and found it exerted antiinflammatory effects on Salmonella enterica serovar Typhimurium (Sal)-induced secretion of IL-8. The current investigation evaluated the antiinflammatory actions of Bacillus bacteria available commercially as feed additives for the swine industry. Three isolates were obtained from the product, 2 Bacillus subtilis (BS1 and BS3) and 1 BL (BL2). Swine jejunal epithelial IPEC-J2 cells were seeded into wells on permeable membrane supports and allowed to form confluent monolayers. Treatments included apical pretreatment with BL, BS1, BL2, or BS3 for 17 h without Sal, and the same Bacillus treatments but with 10(8) cfu of Sal added in the final hour of Bacillus incubation. Two additional treatments included negative control wells receiving no bacteria (control) and positive control wells receiving only Sal (10 total treatments). After bacterial incubation, wells were washed and fresh medium containing gentamicin was added. Cells were incubated for an additional 5 h, after which apical and basolateral media were recovered for determination of IL-8 and bacitracin. In addition, inserts with epithelial cells that had received Sal were lysed and lysates were cultured to determine treatment effects on Sal invasion. Exposure to Sal alone provoked an increase in IL-8 secretion from IPEC-J2 cells compared with control wells (P < 0.001 for both the apical and basolateral directions). Pretreatment with each Bacillus isolate followed by challenge with Sal reduced Sal-induced IL-8 secretion in both the apical and basolateral compartments compared with wells receiving only Sal (P < 0.001; except for BS3 apical, P < 0.01). The residual presence of bacitracin could be detected only in BL2 and BL2+Sal. Fewer Sal colonies could be cultured from lysates of BL2+Sal than from the Sal, BS1+Sal, and BS3+Sal treatments (P < 0.001). Results indicate that B. subtilis and BL have the ability to intervene in secretion of the neutrophil chemoattractant IL-8 from swine intestinal epithelial cells. This effect on chemokine secretion by gastrointestinal epithelial cells in vitro could not be explained solely by reduced invasion of epithelial cells by Sal.
先前的研究评估了实验室培养的地衣芽孢杆菌（BL）在猪肠上皮细胞模型中的作用，发现其对肠炎沙门氏菌（Sal）诱导的 IL-8 分泌具有抗炎作用。本研究评估了商业上作为猪饲料添加剂的 Bacillus 细菌的抗炎作用。从该产品中获得了 3 个分离株，分别为 2 株枯草芽孢杆菌（BS1 和 BS3）和 1 株 BL（BL2）。猪空肠上皮细胞 IPEC-J2 细胞接种于微孔膜支持物的孔中，形成紧密连接的单层。处理包括在没有 Sal 的情况下用 BL、BS1、BL2 或 BS3 进行 17 小时的顶端预处理，以及相同的 Bacillus 处理，但在 Bacillus 孵育的最后 1 小时添加 10（8）cfu 的 Sal。另外两个处理包括不接收细菌的阴性对照孔（对照）和仅接收 Sal 的阳性对照孔（总共 10 个处理）。细菌孵育后，冲洗孔并加入含有庆大霉素的新鲜培养基。细胞再孵育 5 小时，然后从顶端和基底外侧回收培养基以测定 IL-8 和杆菌肽。此外，接收 Sal 的上皮细胞插入物被裂解，并且裂解物被培养以确定处理对 Sal 入侵的影响。与对照孔相比，单独暴露于 Sal 会引起 IPEC-J2 细胞中 IL-8 分泌的增加（顶端和基底外侧方向均为 P<0.001）。用每个 Bacillus 分离物预处理，然后用 Sal 挑战，与仅接收 Sal 的孔相比，降低了 Sal 诱导的顶端和基底外侧腔室中的 IL-8 分泌（P<0.001；BS3 顶端除外，P<0.01）。仅在 BL2 和 BL2+Sal 中可以检测到杆菌肽的残留。从 BL2+Sal 的裂解物中培养的 Sal 菌落比从 Sal、BS1+Sal 和 BS3+Sal 处理中培养的 Sal 菌落少（P<0.001）。结果表明，枯草芽孢杆菌和 BL 具有干预猪肠道上皮细胞中中性粒细胞趋化因子 IL-8 分泌的能力。这种对胃肠道上皮细胞趋化因子分泌的影响不能仅用 Sal 对上皮细胞侵袭的减少来解释。
