Abstract

After birth, the gut becomes colonized by billions of commensal bacteria in parallel with the appearance of numerous isolated lymphoid follicles (ILFs) along the length of the intestine. Now, a recent study published in Nature has pinned down the molecular mechanism for the genesis of ILFs in mice, showing that this process requires the detection of peptidoglycan from Gram-negative bacteria by the innate immune sensor NOD1 (nucleotide-binding oligomerization domain protein 1).