Rossoni Rodnei Dennis, Fuchs Beth Burgwyn, de Barros Patrícia Pimentel, Velloso Marisol Dos Santos, Jorge Antonio Olavo Cardoso, Junqueira Juliana Campos, Mylonakis Eleftherios
Department of Biosciences and Oral Diagnosis, Univ Estadual Paulista/UNESP, São José dos Campos, São Paulo, Brazil.
Division of Infectious Diseases, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America.
PLoS One. 2017 Mar 7;12(3):e0173332. doi: 10.1371/journal.pone.0173332. eCollection 2017.
Probiotics have been described as a potential strategy to control opportunistic infections due to their ability to stimulate the immune system. Using the non-vertebrate model host Galleria mellonella, we evaluated whether clinical isolates of Lactobacillus spp. are able to provide protection against Candida albicans infection. Among different strains of Lactobacillus paracasei, Lactobacillus rhamnosus and Lactobacillus fermentum, we verified that L. paracasei 28.4 strain had the greatest ability to prolong the survival of larvae infected with a lethal dose of C. albicans. We found that the injection of 107 cells/larvae of L. paracasei into G. mellonella larvae infected by C. albicans increased the survival of these insects compared to the control group (P = 0.0001). After that, we investigated the immune mechanisms involved in the protection against C. albicans infection, evaluating the number of hemocytes and the gene expression of antifungal peptides. We found that L. paracasei increased the hemocyte quantity (2.38 x 106 cells/mL) in relation to the control group (1.29 x 106 cells/mL), indicating that this strain is capable of raising the number of circulating hemocytes into the G. mellonella hemolymph. Further, we found that L. paracasei 28.4 upregulated genes that encode the antifungal peptides galiomicin and gallerymicin. In relation to the control group, L. paracasei 28.4 increased gene expression of galiomicin by 6.67-fold and 17.29-fold for gallerymicin. Finally, we verified that the prophylactic provision of probiotic led to a significant reduction of the number of fungal cells in G. mellonella hemolymph. In conclusion, L. paracasei 28.4 can modulate the immune system of G. mellonella and protect against candidiasis.
由于益生菌具有刺激免疫系统的能力，它们已被描述为控制机会性感染的一种潜在策略。我们使用非脊椎动物模型宿主黄粉虫（Galleria mellonella），评估了乳酸杆菌属（Lactobacillus spp.）的临床分离株是否能够提供针对白色念珠菌（Candida albicans）感染的保护作用。在副干酪乳杆菌（Lactobacillus paracasei）、鼠李糖乳杆菌（Lactobacillus rhamnosus）和发酵乳杆菌（Lactobacillus fermentum）的不同菌株中，我们证实副干酪乳杆菌28.4菌株在延长感染致死剂量白色念珠菌的幼虫存活时间方面能力最强。我们发现，与对照组相比，将107个副干酪乳杆菌细胞/幼虫注射到感染白色念珠菌的黄粉虫幼虫中可提高这些昆虫的存活率（P = 0.0001）。之后，我们研究了针对白色念珠菌感染的保护作用所涉及的免疫机制，评估了血细胞数量和抗真菌肽的基因表达。我们发现，与对照组（1.29×106个细胞/毫升）相比，副干酪乳杆菌使血细胞数量增加（2.38×106个细胞/毫升），这表明该菌株能够增加黄粉虫血淋巴中循环血细胞的数量。此外，我们发现副干酪乳杆菌28.4上调了编码抗真菌肽加里米星（galiomicin）和加里米星（gallerymicin）的基因。与对照组相比，副干酪乳杆菌28.4使加里米星的基因表达增加了6.67倍，使加里米星的基因表达增加了17.29倍。最后，我们证实预防性提供益生菌可显著减少黄粉虫血淋巴中的真菌细胞数量。总之，副干酪乳杆菌28.4可调节黄粉虫的免疫系统并预防念珠菌病。
