Department of Molecular Biotechnology, Da-Yeh University, Changhwa 515, Taiwan.
Biometals. 2010 Jun;23(3):543-54. doi: 10.1007/s10534-010-9298-0. Epub 2010 Feb 11.
In this study, Lactobacillus casei was used to deliver and express human lactoferrin (hLF) to protect the host against bacterial infection. Full-length hLF cDNA was cloned into a Lactobacillus-specific plasmid to produce the L. casei transformants (rhLF/L. casei). Antimicrobial activity of recombinant hLF was examined in inhibition of bacteria growth in vitro. A mouse model was established to test in vivo antibacterial activity and protective effect of orally-administered probiotic L. casei transformant in the gastrointestinal tract. Trials were conducted in which animals were challenged with E. coli ATCC25922. E. coli colony numbers in duodenal fluid from the group fed with rhLF/L. casei were significantly lower than those of the group fed with wild-type L. casei or placebo (P < 0.01). Histopathological analyses of the small intestine, showed both decreased intestinal injury and increased villi length were observed in the mice fed with rhLF/L. casei as compared with the control groups (P < 0.01). Our results demonstrate that L. casei expressing hLF exhibited antibacterial activity both in in vitro and in vivo. It also provides a potentially large-scale production of hLF as applications for treatment of infections caused by clinically relevant pathogens.
在这项研究中，使用干酪乳杆菌来递送和表达人乳铁蛋白（hLF），以保护宿主免受细菌感染。将全长 hLF cDNA 克隆到乳杆菌特异性质粒中，以产生干酪乳杆菌转化体（rhLF/L. casei）。在体外抑制细菌生长的实验中，检测了重组 hLF 的抗菌活性。建立了一个小鼠模型，以测试口服益生菌干酪乳杆菌转化体在胃肠道中的体内抗菌活性和保护作用。在这些试验中，用 E. coli ATCC25922 对动物进行了挑战。与用野生型干酪乳杆菌或安慰剂喂养的组相比，用 rhLF/L. casei 喂养的组的十二指肠液中的大肠杆菌菌落数量明显更低（P<0.01）。与对照组相比，用 rhLF/L. casei 喂养的小鼠的小肠组织学分析显示，肠道损伤减少，绒毛长度增加（P<0.01）。我们的研究结果表明，表达 hLF 的干酪乳杆菌在体外和体内均具有抗菌活性。它还为大规模生产 hLF 提供了可能，可用于治疗与临床相关的病原体引起的感染。
