Might interest some and perhaps be worth keeping an eye out for new studies.
In any case, this process is probably all messed up in us.
Researchers identify unexpected player in intestinal immunity: (slightly older 2012)news.wustl.edu/news/Pages/23546.aspx
Here is the full study: Goblet cells deliver luminal antigen to CD103+ DCs in the small intestine www.ncbi.nlm.nih.gov/pmc/articles/PMC3313460/
Newer findings (2014) in the colon:
Microbial sensing by goblet cells controls immune surveillance of luminal antigens in the colon:www.nature.com/mi/journal/vaop/ncurrent/full/mi201458a.html