Limits...
Novel Autoantigens Associated with Lupus Nephritis.

Onishi S, Adnan E, Ishizaki J, Miyazaki T, Tanaka Y, Matsumoto T, Suemori K, Shudou M, Okura T, Takeda H, Sawasaki T, Yasukawa M, Hasegawa H - PLoS ONE (2015)

Bottom Line: To obtain other autoantibodies associated with LN, we screened autoantigens reacting with the sera of LN patients by using an N-terminal biotinylated protein library created from a wheat cell-free protein production system.Both proteins are cationic, and their respective antibodies did not cross-react with dsDNA.These autoantibodies may be useful for prediction of LN in subsets of SLE patients who are negative for anti-dsDNA antibodies.

View Article: PubMed Central - PubMed

Affiliation: Department of Hematology, Clinical Immunology and Infectious Diseases, Ehime University Graduate School of Medicine, Ehime, Japan.

ABSTRACT
Systemic lupus erythematosus (SLE) is characterized by production of a variety of autoantibodies. Although anti-double-stranded DNA (anti-dsDNA) antibodies contribute to the pathogenesis of lupus nephritis (LN), they are not sufficient for diagnosis and evaluation of disease activity. To obtain other autoantibodies associated with LN, we screened autoantigens reacting with the sera of LN patients by using an N-terminal biotinylated protein library created from a wheat cell-free protein production system. We screened 17 proteins that showed higher positive signals in the active phase than in the inactive phase of SLE, and higher positive signals in the serum of SLE patient with nephritis than in that of patient without nephritis. Of these, two LN-associated autoantigens, ribosomal RNA-processing protein 8 (RRP8) and spermatid nuclear transition protein 1 (TNP1) were identified by immunoprecipitation and immunofluorescence of renal tissues. Circulating anti-RRP8 and anti-TNP1 autoantibodies were recognized and deposited as an immune complex (IC) in glomeruli. IC was deposited preferentially in glomeruli rather than in other organs in C57BL/6 mice injected with RRP8 or TNP1. ELISA analysis of sera from patients with various rheumatic diseases demonstrated reactivity for RRP8 and TNP1 in 20% and 14.7% of SLE patients, respectively, whereas there was little or no reactivity in patients with other rheumatic diseases. Among SLE patients, 63.6% and 45.5% of those with LN were positive for anti-RRP8 and anti-TNP1 antibodies, compared with 12.5% and 9.4% of SLE patients without nephritis, respectively. Both proteins are cationic, and their respective antibodies did not cross-react with dsDNA. These proteins released from apoptotic cells form ICs with each autoantibody, and their ICs may become trapped at anionic sites in the glomerular basement membrane, leading to deposition in glomeruli. These autoantibodies may be useful for prediction of LN in subsets of SLE patients who are negative for anti-dsDNA antibodies.

No MeSH data available.


Related in: MedlinePlus

Immunoelectron microscopy of kidney sections from RRP8-injected (A and B) or TNP1-injected (C and D) mice.Photographs show the characteristic dense deposit in the subendothelial part especially at around the border of pericapillary and perimesangial areas. Panel B (anti-RRP8) and Panel D (anti-TNP1) show the high-power view of the deposition which manifests the adjacent (within 30nm) of RRP8 or TNP1 represented by 10-nm-gold particles and IgG represented by 5-nm-gold particles (circle area). *, electron-dense deposit; PD, podocyte; GBM, glomerular basement membrane.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4476694&req=5

pone.0126564.g008: Immunoelectron microscopy of kidney sections from RRP8-injected (A and B) or TNP1-injected (C and D) mice.Photographs show the characteristic dense deposit in the subendothelial part especially at around the border of pericapillary and perimesangial areas. Panel B (anti-RRP8) and Panel D (anti-TNP1) show the high-power view of the deposition which manifests the adjacent (within 30nm) of RRP8 or TNP1 represented by 10-nm-gold particles and IgG represented by 5-nm-gold particles (circle area). *, electron-dense deposit; PD, podocyte; GBM, glomerular basement membrane.

Mentions: Moreover, to determine the deposition of ICs involving RRP8 or TNP1, immunoelectron microscopy was performed. Both RRP8-injected and TNP1-injected mice revealed subendothelial electron-dense deposits in low-power view (Fig 8A and 8C), especially around the border of pericapillary and perimesangial areas. High magnification demonstrated adjacent RRP8 or TNP1 represented by deposition of 10-nm gold particles and IgG represented by 5-nm gold particles (Fig 8B and 8D). These findings also indicate the deposition of IC involving RRP8 or TNP1 in glomeruli. On the other hand, inflammatory changes such as vasculitis and infiltrating inflammatory cells were hardly observed in the lung, liver and spleen of both RRP8-injected and TNP1-injected mice (S3–S9 Figs). In addition, IC deposits with RRP8 or TNP1 were not detected in the lung, liver and spleen of both RRP8-injected and TNP1-injected mice by immunofluorescence staining (S3–S9 Figs). These findings indicate that the IC formed with RRP8 or TNP1 is deposited preferentially in glomeruli, rather than in other organs.


Novel Autoantigens Associated with Lupus Nephritis.

Onishi S, Adnan E, Ishizaki J, Miyazaki T, Tanaka Y, Matsumoto T, Suemori K, Shudou M, Okura T, Takeda H, Sawasaki T, Yasukawa M, Hasegawa H - PLoS ONE (2015)

Immunoelectron microscopy of kidney sections from RRP8-injected (A and B) or TNP1-injected (C and D) mice.Photographs show the characteristic dense deposit in the subendothelial part especially at around the border of pericapillary and perimesangial areas. Panel B (anti-RRP8) and Panel D (anti-TNP1) show the high-power view of the deposition which manifests the adjacent (within 30nm) of RRP8 or TNP1 represented by 10-nm-gold particles and IgG represented by 5-nm-gold particles (circle area). *, electron-dense deposit; PD, podocyte; GBM, glomerular basement membrane.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4476694&req=5

pone.0126564.g008: Immunoelectron microscopy of kidney sections from RRP8-injected (A and B) or TNP1-injected (C and D) mice.Photographs show the characteristic dense deposit in the subendothelial part especially at around the border of pericapillary and perimesangial areas. Panel B (anti-RRP8) and Panel D (anti-TNP1) show the high-power view of the deposition which manifests the adjacent (within 30nm) of RRP8 or TNP1 represented by 10-nm-gold particles and IgG represented by 5-nm-gold particles (circle area). *, electron-dense deposit; PD, podocyte; GBM, glomerular basement membrane.
Mentions: Moreover, to determine the deposition of ICs involving RRP8 or TNP1, immunoelectron microscopy was performed. Both RRP8-injected and TNP1-injected mice revealed subendothelial electron-dense deposits in low-power view (Fig 8A and 8C), especially around the border of pericapillary and perimesangial areas. High magnification demonstrated adjacent RRP8 or TNP1 represented by deposition of 10-nm gold particles and IgG represented by 5-nm gold particles (Fig 8B and 8D). These findings also indicate the deposition of IC involving RRP8 or TNP1 in glomeruli. On the other hand, inflammatory changes such as vasculitis and infiltrating inflammatory cells were hardly observed in the lung, liver and spleen of both RRP8-injected and TNP1-injected mice (S3–S9 Figs). In addition, IC deposits with RRP8 or TNP1 were not detected in the lung, liver and spleen of both RRP8-injected and TNP1-injected mice by immunofluorescence staining (S3–S9 Figs). These findings indicate that the IC formed with RRP8 or TNP1 is deposited preferentially in glomeruli, rather than in other organs.

Bottom Line: To obtain other autoantibodies associated with LN, we screened autoantigens reacting with the sera of LN patients by using an N-terminal biotinylated protein library created from a wheat cell-free protein production system.Both proteins are cationic, and their respective antibodies did not cross-react with dsDNA.These autoantibodies may be useful for prediction of LN in subsets of SLE patients who are negative for anti-dsDNA antibodies.

View Article: PubMed Central - PubMed

Affiliation: Department of Hematology, Clinical Immunology and Infectious Diseases, Ehime University Graduate School of Medicine, Ehime, Japan.

ABSTRACT
Systemic lupus erythematosus (SLE) is characterized by production of a variety of autoantibodies. Although anti-double-stranded DNA (anti-dsDNA) antibodies contribute to the pathogenesis of lupus nephritis (LN), they are not sufficient for diagnosis and evaluation of disease activity. To obtain other autoantibodies associated with LN, we screened autoantigens reacting with the sera of LN patients by using an N-terminal biotinylated protein library created from a wheat cell-free protein production system. We screened 17 proteins that showed higher positive signals in the active phase than in the inactive phase of SLE, and higher positive signals in the serum of SLE patient with nephritis than in that of patient without nephritis. Of these, two LN-associated autoantigens, ribosomal RNA-processing protein 8 (RRP8) and spermatid nuclear transition protein 1 (TNP1) were identified by immunoprecipitation and immunofluorescence of renal tissues. Circulating anti-RRP8 and anti-TNP1 autoantibodies were recognized and deposited as an immune complex (IC) in glomeruli. IC was deposited preferentially in glomeruli rather than in other organs in C57BL/6 mice injected with RRP8 or TNP1. ELISA analysis of sera from patients with various rheumatic diseases demonstrated reactivity for RRP8 and TNP1 in 20% and 14.7% of SLE patients, respectively, whereas there was little or no reactivity in patients with other rheumatic diseases. Among SLE patients, 63.6% and 45.5% of those with LN were positive for anti-RRP8 and anti-TNP1 antibodies, compared with 12.5% and 9.4% of SLE patients without nephritis, respectively. Both proteins are cationic, and their respective antibodies did not cross-react with dsDNA. These proteins released from apoptotic cells form ICs with each autoantibody, and their ICs may become trapped at anionic sites in the glomerular basement membrane, leading to deposition in glomeruli. These autoantibodies may be useful for prediction of LN in subsets of SLE patients who are negative for anti-dsDNA antibodies.

No MeSH data available.


Related in: MedlinePlus