Commensal Microbes Induce Serum IgA Responses that Protect against Polymicrobial Sepsis.
Wilmore JR, Gaudette BT, Gomez Atria D, Hashemi T, Jones DD, Gardner CA, Cole SD, Misic AM, Beiting DP, Allman D
Cell Host Microbe. Mar 2018
COMMENT: In this interesting paper the authors investigate the relationship between the gut microbiome in mice and the presence and levels of IgA in blood and plasma cell in Bone Marrow.
Exposing conventional mice to a unique but natural microflora that included several members of the Proteobacteria phylum led to T cell-dependent increases in serum IgA levels and the induction of large numbers of IgA-secreting plasma cells in the bone marrow
In addition they analise the efect that the introduction of certain bacteria taxa in the gut microbiome seems to have in the susceptibility of having sepsis
Movement to a Proteobacteria- rich microbiota led to serum IgA-mediated resistance to polymicrobial sepsis
The authors say that their results
demonstrate that a variety of commensal bacterial taxa elicit serum IgA responses, resulting in protective activity against polymicrobial sepsis and a marked remodeling of the BM plasma cell pool.
They also say that:
Pre-existing serum IgA antibodies play a unique role in the context of bacterial sepsis, especially when the microbes in question originate from the gut microbiota
We conclude that commensal microbes overtly influence the serum IgA repertoire, resulting in constitutive protection against bacterial sepsis.