A population of resting IgM-IgD double-bearing lymphocytes in Peyer's patches: the major precursor cells for IgA plasma cells in the gut lamina propria.

The precursor cells in Peyer's patches and mesenteric lymph nodes responsible for repopulating IgA plasma cells in the gut lamina propria were identified by using cell separation and by using cell transfer in Ig allotype congeneic mice (CB-20 and BALB/cJ mice). It was found that the IgA precursor cells are mainly resting lymphoid cells bearing IgM and IgD on their surface. The IgA-bearing cells are also precursors; their repopulation efficiency, however, is remarkably low. The majority of the IgA precursor cells also bear complement receptors on their surface; this suggests that they are relatively mature B cells.