Symbiotic bacteria direct expression of an intestinal bactericidal lectin

HL Cash, CV Whitham, CL Behrendt, LV Hooper - Science, 2006 - science.org
HL Cash, CV Whitham, CL Behrendt, LV Hooper
Science, 2006science.org
The mammalian intestine harbors complex societies of beneficial bacteria that are
maintained in the lumen with minimal penetration of mucosal surfaces. Microbial
colonization of germ-free mice triggers epithelial expression of RegIIIγ, a secreted C-type
lectin. RegIIIγ binds intestinal bacteria but lacks the complement recruitment domains
present in other microbe-binding mammalian C-type lectins. We show that RegIIIγ and its
human counterpart, HIP/PAP, are directly antimicrobial proteins that bind their bacterial …
The mammalian intestine harbors complex societies of beneficial bacteria that are maintained in the lumen with minimal penetration of mucosal surfaces. Microbial colonization of germ-free mice triggers epithelial expression of RegIIIγ, a secreted C-type lectin. RegIIIγ binds intestinal bacteria but lacks the complement recruitment domains present in other microbe-binding mammalian C-type lectins. We show that RegIIIγ and its human counterpart, HIP/PAP, are directly antimicrobial proteins that bind their bacterial targets via interactions with peptidoglycan carbohydrate. We propose that these proteins represent an evolutionarily primitive form of lectin-mediated innate immunity, and that they reveal intestinal strategies for maintaining symbiotic host-microbial relationships.
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