Department of Invertebrate Immunology, Institute of Biology, Maria Curie-Skłodowska University, 19 Akademicka St., 20-033 Lublin, Poland.
Comp Biochem Physiol B Biochem Mol Biol. 2011 Jan;158(1):90-8. doi: 10.1016/j.cbpb.2010.10.001. Epub 2010 Oct 16.
Apolipophorin III (apoLp-III) is an abundant hemolymph protein involved in lipid transport and immune response in insects. We investigated involvement of apoLp-III in the antibacterial response in Galleria mellonella larvae. Immune challenge with Gram-negative (Escherichia coli, Klebsiella pneumoniae) and Gram-positive (Micrococcus luteus) bacteria led to an increase in the level of apoLp-III in G. mellonella hemolymph, 0.5-2h and 8h after treatment, respectively. ApoLp-III purified from larval hemolymph as well as that present in hemolymph extracts adsorbed on the surface of different bacteria. The adsorption capacity of apoLp-III on bacterial cells prompted us to investigate the effect of this phenomenon on bacterial growth. Our results demonstrate antibacterial activity of apoLp-III against selected Gram-positive and Gram-negative bacteria in vitro. Among bacteria tested, Salmonella typhimurium and K. pneumoniae were the most sensitive to apoLp-III. LIVE/DEAD staining of bacteria incubated with purified apoLp-III revealed their growth inhibition; however, neither morphological changes in the cell shape nor formation of cell aggregates was noticed. The results suggest that apoLp-III is a multifunctional protein in G. mellonella hemolymph.
载脂蛋白 III（apoLp-III）是一种丰富的血淋巴蛋白，参与昆虫的脂质运输和免疫反应。我们研究了 apoLp-III 在大蜡螟幼虫的抗菌反应中的作用。革兰氏阴性（大肠杆菌、肺炎克雷伯菌）和革兰氏阳性（藤黄微球菌）细菌的免疫挑战导致大蜡螟血淋巴中 apoLp-III 的水平分别在处理后 0.5-2 小时和 8 小时增加。从幼虫血淋巴中纯化的 apoLp-III 以及血淋巴提取物中存在的 apoLp-III 吸附在不同细菌的表面。apoLp-III 对细菌细胞的吸附能力促使我们研究这种现象对细菌生长的影响。我们的结果表明，apoLp-III 在体外对选定的革兰氏阳性和革兰氏阴性细菌具有抗菌活性。在测试的细菌中，鼠伤寒沙门氏菌和肺炎克雷伯菌对 apoLp-III 最敏感。用纯化的 apoLp-III 孵育的细菌的 LIVE/DEAD 染色显示其生长受到抑制；然而，没有注意到细胞形状的形态变化或细胞聚集的形成。结果表明，apoLp-III 是大蜡螟血淋巴中的一种多功能蛋白。
