Figure 6.

Mechanism of FRC-like cell–mediated immune regulation. A: Heat map of T1D autoantigen expression in gp38^dim FRC-like cells freshly sorted from either Ins2-CCL21 NOD mice or nontransgenic NOD littermates analyzed byRNAseq. T1D autoantigens: carboxypeptidase E (Cpe), pancreatic and duodenal homeobox 1 (Pdx1), islet cell autoantigen 1 (Ica1), chromogranin A (Chga), pancreatic polypeptide (Ppy), islet amyloid polypeptide (Iapp), solute carrier family 30 member 8 (Slc30a8), insulin 2 (Ins2), protein tyrosine phosphatase, receptor type N (Ptprn), glucagon (Gcg), insulin (Ins1), and regenerating family member 3 α (Reg3a). B: Confocal microscope images of pancreatic sections of 4-week-old nontransgenic (top) and Ins2-CCL21 transgenic (bottom, different magnifications) NOD mice immunostained with insulin (red), pan-laminin (gray), stromal cell (gp38, green) antibodies, and nuclear counterstain (DAPI, blue). Scale bar, 50 μm. Bottom panels are higher magnifications of the areas indicated by the white boxes. C: Principal component analysis (PCA) of gene expression in LN-derived FRCs (n = 4 for nontransgenic NOD and n = 3 for Ins2-CCL21 NOD), islet-derived gp38^dim FRC-like cells (n = 4 per mouse model), islet-derived gp38^hi FRC-like cells (n = 2 per mouse model), and islet-derived CD45⁺ cells (n = 4 per mouse model) freshly sorted from 12-week-old Ins2-CCL21 NOD mice and from control NOD littermates. D: Heat map of significantly relevant (false discovery rate <0.05) inflammatory genes (list of genes taken from the Nanostring Immunology panel available on their website) in islet-derived gp38^dim FRC-like cells from Ins2-CCL21 NOD mice compared with nontransgenic littermates. E: Heat map of inflammatory genes (Nanostring Immunology panel) expressed by LN-derived FRCs, islet-derived gp38^dim FRC-like cells, islet-derived gp38^hi FRC-like cells, and islet-derived CD45⁺ cells freshly sorted from 12-week-old Ins2-CCL21 NOD mice (right) or nontransgenic littermates (left). wks, weeks.