Stromal cells produce cxcl13 attracting B cells and they have 3 areas of importance

Stromal cells produce cxcl13 attracting B cells and they have 3 areas of importance: two stromal cells in the lymph node ; one area is for internal antigens and  the other area is for outer antigens. The third stromal cell area is for catching infections that have escaped the gut's organs in the omentum zone.

adipose stromal cells
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3481843/

omentum milky fat spots have adipose stromal cells (ASC) which produce the CXCL13
the B1 cells involved there are the primary source of IgM
https://www.researchgate.net/publication/265860846_Human_adipose_tissue-derived_mesenchymal_stromal_cells_promote_B-cell_motility_and_chemoattraction

Marginal Reticular cells MRC are mesenchymal stromal cells of the scs area

Fibroblastic Reticular cells  FRC are bundled into the conduit leading to the follicular dendritic cells

All 3 of these stromal subsets make cxcl13 which attract B cells and follicular T cells thus creating the germinal centers
https://www.ncbi.nlm.nih.gov/pubmed/28454789

The MRC-SCS zone creates antibodies against the inner antigens (IgG2 or IgG3)  while the FRC-FDC zone creates the antigens against the outer antigens.  (IgG1 at the spleen, IgE at the lymph, and IgA dimers in peyer patches.)  The milky spots with the ASC attract the B1 cells thus producing IgM.

MRC was thought to transport antigens from SCS to FDC which could be the differentiation of MRC into FDC of inner antigens.
http://jem.rupress.org/content/211/6/1109
https://www.ncbi.nlm.nih.gov/pubmed/?term=jem.20132409

Does SCS not present to B cells directly rather hands the antigen to MRC who presents?

Here is a paper that has the SCS handing off to a nonphagocytic cell they call ATC (antigen transporting cell ) that appears to mature into a FDC type of cell
https://www.jimmunol.org/content/131/4/1714.long

MRC as phagocyte of apoptotic B cells
https://www.ncbi.nlm.nih.gov/pubmed/29686051

Is this incase the B cells are infected?

the conduit transports soluble antigens
https://www.ncbi.nlm.nih.gov/pubmed/15664156

Langerhans bring antigen through conduit
https://www.ncbi.nlm.nih.gov/pubmed/16818784

exosomes derived from dendritic cells migrate to spleen
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5320445/

cd169 mediates the capture of exosomes
https://www.ncbi.nlm.nih.gov/pubmed/24255917

25hc and viral infections
https://www.nature.com/articles/nri3755/figures/4

immature exosomes teach tolerance while mature dendritic cell exosomes induce immune reaction
https://link.springer.com/article/10.1007/s10753-012-9539-1

scs and viral infection of the central nervous system
https://www.nature.com/articles/nature09118