New therapeutics are urgently needed for infectious diseases, especially for the fungal infection like Fonsecaea monophora. Photodynamic therapy has been showing antimicrobial activity on some pathogens. The combination of antimicrobial medicines and photodynamic therapy (PDT) might be a practical approach. However, whether the treatment of PDT could do benefits to the host immunity remains poorly documented. In this study, Galleria mellonella larvae were employed as a model organism to evaluate the activity of PDT, and also to investigate the regulation of humoral immunity by PDT. Photosensitizer 5-aminolevulinic acid (ALA) was applied to the G. mellonella infection model. It was found that ALA-mediated PDT was non-toxic to G. mellonella, and could extend the median survival of infected larvae from 3 days to 5.5 days. We observed that larval hemocytes inhibited the growth of Candida albicans and Staphylococcus aureus, without any contribution by ALA-PDT. Furthermore, the application of ALA-PDT demonstrated the immunomodulation of larval innate immunity as increased hemocyte density counting, cell morphological transformation, and sensitivity to pathogens. G. mellonella could be considered as a useful model to study the immunoregulation of PDT. This model revealed that ALA-PDT positively defense against infections through inducing humoral immune responses of larvae.

中文翻译：

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梅隆内广场模型的光动力疗法的抗菌和免疫调节反应。

传染性疾病，尤其是真菌感染，如丰氏金龟子，迫切需要新的疗法。光动力疗法已对某些病原体显示出抗菌活性。抗菌药物和光动力疗法（PDT）的结合可能是一种实用的方法。但是，PDT的治疗是否可以对宿主的免疫产生益处仍然文献不足。在这项研究中，以Galleria mellonella幼虫作为模型生物来评估PDT的活性，并研究PDT对体液免疫的调节。将光敏剂5-氨基乙酰丙酸（ALA）应用于梅勒菌的感染模型。研究发现，ALA介导的PDT对mel。melonella无毒，可将受感染幼虫的中位生存期从3天延长至5.5天。我们观察到，幼虫血细胞抑制了白色念珠菌和金黄色葡萄球菌的生长，而ALA-PDT没有任何作用。此外，ALA-PDT的应用证明了幼虫先天免疫的免疫调节是增加的血细胞密度计数，细胞形态转化和对病原体的敏感性。mellonella菌可以被认为是研究PDT免疫调节的有用模型。该模型表明，ALA-PDT通过诱导幼虫的体液免疫反应来积极防御感染。和对病原体的敏感性。mellonella菌可以被认为是研究PDT免疫调节的有用模型。该模型表明，ALA-PDT通过诱导幼虫的体液免疫反应来积极防御感染。和对病原体的敏感性。mellonella菌可以被认为是研究PDT免疫调节的有用模型。该模型表明，ALA-PDT通过诱导幼虫的体液免疫反应来积极防御感染。