Maternal IgG and IgA Antibodies Dampen Mucosal T Helper Cell Responses in Early Life
Monday, August 29, 2016
Koch MA, Reiner GL, Lugo KA, Kreuk LS, Stanbery AG, Ansaldo E, Seher TD, Ludington WB, Barton GM.
Immediately following birth, the gastrointestinal tract is colonized by diverse microbial species. Establishing proper immune responses to these microbes is essential to ensure optimal growth and overall health during the neonatal development period. Along with commensal microbes, mammalian mothers provide nutrients and immunomodulatory factors to their young through breast milk. By comparing offspring of antibody sufficient and deficient mothers, we found that antibodies derived from breast milk were required to limit mucosal effector CD4+ T cell responses in neonatal mice. Within breast milk, IgA is the most abundant antibody isotype, and IgA antibodies have long been appreciated to mediate host-commensal mutualism. Surprisingly, we observed that young mice lacking maternal IgA did not exhibit the same phenotype as mice lacking all maternal antibodies indicating that other antibody isotypes present in breast milk help dampen mucosal T cell immunity.
We developed a flow cytometry assay to profile the complete anti-commensal antibody response and found, surprisingly, that in addition to IgA, healthy... read more