Chhibber Sanjay, Wadhwa Sunita, Yadav Vanashree
Department of Microbiology, Panjab University, Chandigarh 160014, India.
Jpn J Infect Dis. 2004 Aug;57(4):150-5.
In a lobar pneumonia model of Klebsiella pneumoniae, the immunoprotective role of free lipoploysaccharide (LPS) and liposome-incorporated LPS was studied. An alteration in the biological activity of the LPS molecule, in terms of its pyrogenicity and lethal toxicity, was observed on incorporation in the liposome. Compared at equal doses, liposome-incorporated LPS was found to be non-pyrogenic and 10 times less toxic than free LPS. Liposome-incorporated LPS was more effective in providing protection against K. pneumoniae induced lobar pneumonia in rats. The immunological mechanism underlying protection revealed involvement of both nonspecific and specific immune response. Alveolar macrophage activation was observed after 4 and 14 days of treatment with the free and liposome-entrapped forms of LPS, respectively. Specific immunity in terms of plaque-forming cells was seen with both forms of LPS. Delayed type hypersensitivity reaction was observed only with liposome-incorporated LPS. It is concluded that a non-toxic and immunogenic form of K. pneumoniae LPS can be obtained by incorporation of the native preparation into liposomes.
在肺炎克雷伯菌的大叶性肺炎模型中，研究了游离脂多糖（LPS）和脂质体包裹的LPS的免疫保护作用。当LPS分子掺入脂质体时，观察到其热原性和致死毒性方面的生物活性发生了改变。在相同剂量下比较发现，脂质体包裹的LPS无热原性，毒性比游离LPS低10倍。脂质体包裹的LPS在为大鼠提供针对肺炎克雷伯菌诱导的大叶性肺炎的保护方面更有效。保护作用的免疫机制显示非特异性和特异性免疫反应均参与其中。分别在用游离和脂质体包裹形式的LPS处理4天和14天后观察到肺泡巨噬细胞活化。两种形式的LPS均可见到形成噬斑细胞方面的特异性免疫。仅脂质体包裹LPS观察到迟发型超敏反应。结论是，通过将天然制剂掺入脂质体中可获得无毒且具有免疫原性的肺炎克雷伯菌LPS形式。
