Bifidobacteria from human origin: interaction with phagocytic cells

ASSAD, SABRINA; ROLNY, IVANNA S; MINNAARD J; PEREZ PF

JOURNAL OF APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020

1364-5072

Aim of the studyGiven that phagocytic cells are main players of the host immune response, we studied the interaction of bifidobacteria with monocytic THP-1 cells in non-opsonic conditions. Methods and Results Association/internalization, cell response (expression of HLA-DR and TLR2), M1/M2 macrophage polarization and colocalization of microorganisms with Lysotracker or transferrin were evaluated. Screening with 8 Bifidobacterium strains showed two patterns of interactions with THP-1 cells: high and low association and phagocytosis. Two strains with different surface properties were further studied: B. bifidum CIDCA 5310 and B. adolescentis CIDCA 5317. Higher levels of colocalization in lysosome were found for strain CIDCA 5310. Both strains stimulated TLR2 expression. Strain CIDCA 5317 significantly increases HLA-DR expression, however when cells are stimulated with IFN-γ, strain CIDCA 5310 induces the highest value of expression. Noteworthy, strain CIDCA 5310 was able to upregulate both M1 and M2 markers of macrophage polarization. Conclusions Our results demonstrate that bifidobacteria from human origin show different patterns of interaction with phagocytic cells thus leading to different cell responses. These findings add further insight on the mechanisms involved in the biologic effects of probiotics.Significance and Impact of Study Knowledge of the interaction of bifidobacteria with key players of the host immune response is paramount for the understanding of the mechanisms involved in the beneficial effects. The present study constitutes the first report on this subject.