Pre-exposure of Galleria mellonella larvae to different doses of Aspergillus fumigatus conidia causes differential activation of cellular and humoral immune responses
Pre-exposure of Galleria mellonella larvae to different doses of Aspergillus fumigatus conidia causes differential activation of cellular and humoral immune responses
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DOI：
10.4161/viru.2.5.17811
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发表时间：
2011-09-01
期刊：
影响因子：
5.2
通讯作者：
Kavanagh, Kevin
中科院分区：
文献类型：
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作者：
Fallon, John P.;Troy, Niamh;Kavanagh, Kevin
梅氏盖氏杆菌幼虫是研究微生物病原体毒力或评价抗菌剂效力的有用模型。在这项工作中，我们证明了预先将幼虫暴露于非致死剂量的烟曲霉分生孢子后，24 h后幼虫对致死剂量(1×10(7)20亩L(-1))的抵抗力增强。将幼虫暴露于1×10(4)20亩L(-1)分生孢子中，可使血细胞密度增加，而接种1×10(5)分生孢子则可增加抗菌肽的表达，增加蛋白质(如芳香酚、酚氧化酶、脱脂蛋白)与分生孢子的结合，并增加血细胞密度。这些结果表明，低剂量的分生孢子(1×10(4))主要激活细胞免疫反应，但高剂量(1×10(5))仍不致命的分生孢子在最大程度上激活体液免疫反应。虽然昆虫的免疫系统类似于哺乳动物的先天免疫反应，但这些结果表明，昆虫能够评估微生物挑战的程度，并建立可能具有重要生存优势的“比例”免疫反应。
Larvae of Galleria mellonella are useful models for studying the virulence of microbial pathogens or for evaluating the potency of antimicrobial agents. In this work we demonstrated that prior exposure of larvae to non-lethal doses of Aspergillus fumigatus conidia increases the resistance of larvae to a lethal dose (1 x 10(7) 20 mu l(-1)) 24 h later. Exposure of larvae to a conidia concentration of 1 x 10(4) 20 mu l(-1) leads to an increase in hemocyte density but an inoculum of 1 x 10(5) conidia leads to enhanced expression of antimicrobial peptides, increased binding of proteins (e.g., arylophorin, prophenoloxidase, apolipophorin) to conidia and elevated hemocyte density. These results suggest that a low dose of conidia (1 x 10(4)) predominantly activates the cellular immune response but that a higher dose (1 x 10(5)) that is still not lethal activates a humoral immune response to the greatest extent. While insects have an immune system analogous to the innate immune response of mammals these results suggest that it is capable of assessing the extent of the microbial challenge and mounting a 'proportionate' immune response which may have important survival advantages.