Open AccessLymphoid Tissue–Resident Alcaligenes Establish an Intracellular Symbiotic Environment by Creating a Unique Energy Shift in Dendritic Cells
Author(s) -
Koji Hosomi,
Nao Shibata,
Atsushi Shimoyama,
Tomoya Uto,
Takahiro Nagatake,
Yoko Tojima,
Tomomi Nishino,
Haruko Takeyama,
Koichi Fukase,
Hiroshi Kiyono,
Jun Kunisawa
Publication year - 2020
Publication title -
frontiers in microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.701
H-Index - 135
ISSN - 1664-302X
DOI - 10.3389/fmicb.2020.561005
Subject(s) - alcaligenes faecalis , lipopolysaccharide , biology , intracellular , intracellular parasite , microbiology and biotechnology , chemotaxis , nitric oxide , immune system , escherichia coli , bacteria , immunology , biochemistry , genetics , receptor , gene , endocrinology
Lymphoid-tissue–resident commensal bacteria (LRCs), including Alcaligenes faecalis , are present in intestinal lymphoid tissue including the Peyer’s patches (PPs) of mammals and modulate the host immune system. Although LRCs can colonize within dendritic cells (DCs), the mechanisms through which LRCs persist in DCs and the symbiotic relationships between LRCs and DCs remain to be investigated. Here, we show an intracellular symbiotic system in which the LRC Alcaligenes creates a unique energy shift in DCs. Whereas DCs showed low mitochondrial respiration when they were co-cultured with Escherichia coli , DCs carrying A. faecalis maintained increased mitochondrial respiration. Furthermore, E. coli induced apoptosis of DCs but A. faecalis did not. Regarding an underlying mechanism, A. faecalis —unlike E. coli —did not induce intracellular nitric oxide (NO) production in DCs due to the low activity of its lipopolysaccharide (LPS). Therefore, A. faecalis , an example of LRCs, may persist within intestinal lymphoid tissue because they elicit little NO production in DCs. In addition, the symbiotic DCs exhibit characteristic physiologic changes, including a low rate of apoptosis and increased mitochondrial respiration.