Figure 2.

Major subsets of intestinal B cells show distinct morphology. A, Flow cytometric sorting of intestinal LP B cell lineage cells show 3 major subsets which include CD19+ IgA^neg, CD19+ IgA+ and CD19^neg/IgA positive. Subsequent analysis of the CD19+/IgA+ show that the majority express integrin β7 (likely α4β7) whereas 2% express both αE (CD103) and β7. B, Electron microscopy shows increased rough endoplasmic reticulum and decreased nucleocytoplasmic ratio in cells that express IgA on the cell surface (representative images from Guzman et al.)⁴²