Candidatus Savagella (Segmented filamentous bacteria/SFB)

Candidatus Savagella (Segmented filamentous bacteria/SFB) adheres to epithelial cells in the ileum. It induces CD4+ Th17 cells. These cells express Interleukin-17A (IL-17A), Interleukin-17F (IL-17F), Interleukin-22 (IL-22), and Interleukin-10 (IL-10). They protect the epithelial barrier
Yang et al. 2014 Nature 510: 152-156
Aschenbrenner et al. 2018 Nat Immunol 19: 1126-1136
Brockmann et al. 2023 Immunity 56: 2719-2735

Candidatus Savagella (Segmented filamentous bacteria/SFB) also induces Tfh cells in Peyer’s patches
Teng et al. 2016 Immunity 44: 875-888
Verma et al. 2024 Immunity 57: 14281441

• Segmented filamentous bacteria, also known as Candidatus Savagella, are Gram-positive clostridia-related bacteria that colonize the small intestine of mice and other animals.


• They form a distinct lineage within the Clostridiaceae family.


• Most mice from commercial sources, except for The Jackson Laboratory, are naturally colonized by Candidatus Savagella.


• Candidatus Savagella is considered an obligate anaerobe.

Klaasen et al. 1993 Lab Anim. 27: 141-150
Thompson et al. 2012 Environmental Microbiology 14(6): 1454-65
Yin et al. 2013 Isme j. 7: 615-621
Ericsson et al. 2014 Comp Med. 64: 90-98
Ericsson & Franklin 2015 ILAR Journal 56(2): 205-217

Some Candidatus Savagella (Segmented filamentous bacteria/SFB) -specific T cells become CD4+ CD25+ FOXP3 high Treg (peripherally induced). This is common in mice with only SFB.
Ohnmacht et al. 2015 Science 349: 989–993

These Treg cells express Foxp3 and RORgamma/t. They are also found with other bacteria like Bacteroides thetaiotamicron.
Ohnmacht et al. 2015 Science 349: 989–993
Sefik et al. 2015 Science 349: 993-997
Geva-Zatorsky et al. 2017 Cell 168: 928-943

see also:
Activation / Activators & T helper 17 cell (Th17)
Follicular B Helper T Cells (Tfh)
Gut microbiota & T helper 17 cell (Th17)