Open AccessLactobacillus paracasei modulates the immune system of Galleria mellonella and protects against Candida albicans infection
Author(s) -
Rodnei Dennis Rossoni,
Beth Burgwyn Fuchs,
Patrícia Pimentel de Barros,
Marisol dos Santos Velloso,
Antônio Olavo Cardoso Jorge,
Eleftherios Mylonakis
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0173332
Subject(s) - galleria mellonella , lactobacillus paracasei , candida albicans , microbiology and biotechnology , biology , hemolymph , lactobacillus rhamnosus , corpus albicans , immune system , innate immune system , lactobacillus , immunology , virulence , gene , bacteria , biochemistry , genetics , botany
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 10 7 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 10 6 cells/mL) in relation to the control group (1.29 x 10 6 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.