Great journal club by @basbees on this paper by @ShikaRamanan et al. https://doi.org/10.1016/j.cell.2020.04.030

Multiple">https://doi.org/10.1016/j... https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤯" title="Explodierender Kopf" aria-label="Emoji: Explodierender Kopf"> results: 1/n

1) Cross-fostering experiments (did I mention I https://abs.twimg.com/emoji/v2/... draggable="false" alt="💕" title="Zwei Herzen" aria-label="Emoji: Zwei Herzen"> these?!) show immune phenotype is vertically transferred through MILK (not genetics, epigenetics or microbes)

2. The & #39;active ingredient& #39; in mother& #39;s milk seems to be IgA, which coats bacteria in the offspring& #39;s gut, impacting how these microbes program the developing immune system.

3. This impacts how the offspring produce their own IgA for the REST OF THEIR LIVES! ( #DOHAD, anyone?) 2/n

4. In daughters, this impacts how much IgA is present in the milk they will later feed to THEIR daughters. Therefore the effect of IgA received in mother& #39;s milk is TRANSGENERATIONAL! 3/n

(Shown beautifully in these experiments & figures)

5. This lifelong/transgenerational programming of the immune system through lactation occurs during a very EARLY & SHORT POSTNATAL window (first ~0-7 days of lactation). Mice lactate for 21 days. 4/n

6. Super cool & #39;photocovertible reporter mouse& #39; technology used to show IgA-producing immune cells migrate from maternal gut to mammary gland during late pregnancy! AMAZING! 5/n

7. Authors infer: lack of & #39;lactational programming& #39; in recent generations of formula-fed babies (mothers & grandmothers of current generation) could be contributing to the epidemic of #allergies & autoimmune diseases, which happened too rapidly to be explained by genetics https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤯" title="Explodierender Kopf" aria-label="Emoji: Explodierender Kopf"> 6/n

A great quote from the authors to end:

"We report a novel mode of transmission of maternal factors via the entero-mammary axis that influences
colonic Treg differentiation & function and sets the
immunoregulatory tone in the intestine THROUGH GENERATIONS"

#LactationIsAmazing