No complement receptor 1 stumps on podocytes in human glomerulopathies Solange Moll, Sylvie Miot, Salima Sadallah, Fred Gudat, Michael J. Mihatsch, Jürg A. Schifferli  Kidney International  Volume 59, Issue 1, Pages 160-168 (January 2001) DOI: 10.1046/j.1523-1755.2001.00476.x Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 1 Immunoblotting analysis. (A) Immunoblotting analysis of urinary vesicles (UV; 5% acrylamide gel) with the monoclonal antibody 3D9 (dilution 1/2000). (B) Immunoblotting analysis of the tail peptide (1 μg), recombinant soluble CR1 (rsCR1; 50 ng, 4 to 20% acrylamide gradient gel) and UVs (12% acrylamide gel) with the polyclonal anti-CR1 tail antibody (dilution 1/2000). (C) Immunoblotting analysis of UVs treated or not with human leukocyte elastase (HLE) 9 and 18 μg (4 to 20% acrylamide gradient gel) with the polyclonal anti-CR1 tail antibody (dilution 1/2000) and with the rabbit preimmune IgG. Kidney International 2001 59, 160-168DOI: (10.1046/j.1523-1755.2001.00476.x) Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 2 Normal glomerulus. (A) 3D9, the monoclonal antibody (Ab) reacting with the C3b binding sites of CR1 (that is, the extracellular portion of CR1), provided a strong specific staining of the podocytes. (B) The anti-CR1 tail IgG (that is, the intracellular portion of CR1) provided an identical staining of the podocytes, although there was a weak background staining of most of the renal tissue. (C) Staining was abolished when the tissue sections were incubated with an irrelevant mAb (anti-factor D) or when 3D9 was preincubated with rsCR1 (data not shown). (D) The anti-CR1 tail IgG staining was abolished by preincubating the Ab with purified tail-peptide. (E) The preimmune IgG was negative as well (A–E, magnification ×100). Kidney International 2001 59, 160-168DOI: (10.1046/j.1523-1755.2001.00476.x) Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 3 Different types of glomerulopathies. (A) Lupus nephritis (WHO IV; magnification ×62). (B) IgA nephritis (magnification ×100). (C) Membranous GN (magnification ×100). Concomitant and markedly reduced staining for 3D9, the monoclonal Ab reacting with the C3b binding sites of CR1 (that is, extra-CR1, A1, B1, C1), as well as for the anti-CR1 tail IgG (that is, intra-CR1; A2, B2, C2). Kidney International 2001 59, 160-168DOI: (10.1046/j.1523-1755.2001.00476.x) Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 4 Focal and segmental glomerulosclerosis (FSGS). In areas of synechia formation (arrow) in FSGS (A), a complete loss of the staining for 3D9, the monoclonal Ab reacting with the C3b binding sites of CR1 (that is, extra-CR1) (B) as well as the anti-CR1 tail IgG (that is, intra-CR1), was observed (magnification ×100). Kidney International 2001 59, 160-168DOI: (10.1046/j.1523-1755.2001.00476.x) Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 5 Minimal change disease. The reduction of glomerular staining for the two antibodies (Ab), (A) 3D9, the monoclonal Ab reacting with the C3b binding sites of CR1 (that is, extra-CR1), as well as (B) the anti-CR1 tail IgG (that is, intra-CR1), was observed even in the absence of light microscopic alterations (magnification ×100). In contrast, the glomerular staining for the monoclonal Ab reacting with podocalyxin was strong (C) in the same patient with minimal change disease and was unchanged in comparison with (D) normal renal tissue (magnification ×100). Kidney International 2001 59, 160-168DOI: (10.1046/j.1523-1755.2001.00476.x) Copyright © 2001 International Society of Nephrology Terms and Conditions