Serum anti-β2 spectrin IgA antibodies are produced in a CD4 T cell-independent manner in IgA nephropathy model mouse

Introduction: plasmablasts (PBs) secreting anti-β2-spectrin IgA Abs accumulated in the kidneys of gddY mice. These PBs exhibited a substantial accumulation of somatic hypermutations in both their heavy- and light-chain variable region genes. Methods: PBs in the kidney and serum anti-β2 spectrin Abs were evaluated by Fuji-DRY-CHEM 7000V, enzyme-linked immunosorbent assay, microscopy, flow cytometry and western blotting, respectively. Results: cells). However, The results showed the level of urinary albumin and BUN were no difference in in the anti-CD4 treatment (5627.0 ± 1316.2 μg/dL, 40.3 ± 4.5 mg/dL, respectively) compared to the control (4766.5 ± 809.2 μg/dL, 69.9 ± 33.2, respectively). And also the treatment did not affect the production of anti-β2-spectrin IgA Abs in sera, glomerular IgA deposition nor pathology. Discussion: T cell-independent manner and the PBs infiltrating in the kidney are not the major source of serum anti-β2-spectrin IgA Abs at least in animal model. The present study will help to elucidate the mechanism of production of anti-β2-spectrin IgA Abs.