pSAP administration in the early stage of SLE disease reverses ALD-DNA-induced lupus nephritis.

<p>BALB/c mice were immunized subcutaneously with ALD-DNA (50 µg/mouse) or PBS for total 3 times in 4 weeks. Mice immunized with ALD-DNA were administrated intramuscularly with pSAP (100 µg/mice) from week 4 after initial immunization (with the onset of proteinuria) and injected every 2 weeks for total 5 times. (A) The dynamics of SAP level in serum of lupus mice injected with pSAP (ALD-DNA plus pSAP) or pcDNA3 (ALD-DNA plus pcDNA3) were determined by ELISA assay every 2 weeks. (B) The dynamics of circulating DNA level in serum of lupus mice injected with pSAP (ALD-DNA plus pSAP) or pcDNA3 (ALD-DNA plus pcDNA3) were determined by ELISA assay every 2 weeks. (C) The ratios of SAP to DNA in SLE murine model injected with pSAP (ALD-DNA plus pSAP) or pcDNA3 (ALD-DNA plus pcDNA3) at week 12 after initial immunization. Data are means ± SD from 10 mice in each group. ***, <i>P</i><0.001. (D) Serum anti-dsDNA IgG levels of the mice were measured by ELISA assay every 2 weeks. (E) Anti-dsDNA IgG antibody titers in serum of pSAP-treated lupus mice (ALD-DNA plus pSAP) or pcDNA3-treated lupus mice (ALD-DNA plus pcDNA3) were detected by ELISA assay at week 8 after the initial ALD-DNA immunization. n = 10. (F) Urine protein levels of the mice were assessed by BCA Protein Assay Kit (Thermo Fisher Scientific) every 2 weeks. n = 10. (G) The deposition of IgG-containing IC in glomeruli at week 12 after initial immunization. Imagines (×200) are representative of at least 10 mice in each group. (H) Mean glomerular fluorescence intensity (arbitrary units) was determined for IgG in ALD-DNA-immunized lupus mice and control mice at week 12 after initial immunization. n = 10. **, <i>P</i><0.01. (I) 12 weeks after initial immunization, nephritic pathological changes were shown by H&E staining of renal tissues surgical resected from the mice. Imagines (×200) are representative of at least 10 mice in each group. (J) The kidney score was assessed using paraffin sections stained with H&E. n = 10. ***, <i>P</i><0.001.