BAFF overexpression and accelerated glomerular disease in mice with an incomplete genetic predisposition to systemic lupus erythematosus.
OBJECTIVE
To determine whether overexpression of BAFF can accelerate the development of systemic lupus erythematosus-associated end-organ disease in hosts with an underlying autoimmune diathesis.


METHODS
We introduced a BAFF transgene (Tg) into autoimmune-prone B6.Sle1 and B6.Nba2 mice and evaluated these mice for serologic autoimmunity and renal pathology.


RESULTS
B6.Sle1.BAFF and B6.Nba2.BAFF mice, but not non-Tg littermates, frequently developed severe glomerular pathology by 3 months of age. Age-matched B6.BAFF mice, despite renal Ig deposits and increases in B cells and Ig production similar to those in B6.Sle1.BAFF and B6.Nba2.BAFF mice, did not develop glomerular pathology. In B6.Sle1.BAFF and B6.Nba2.BAFF mice, severity of glomerular disease did not obligately correlate with circulating levels of IgG anti-chromatin and/or anti-double-stranded DNA antibodies or with amounts of these autoantibodies deposited in the kidneys. Even in mice with severe glomerular disease, renal tubulointerstitial infiltrates were very limited, and increased proteinuria was not detected.


CONCLUSIONS
BAFF-driven effects on glomerular pathology may be mediated, at least in part, by autoantibodies with specificities other than chromatin and/or by autoantibody-independent means. There is an uncoupling of BAFF-driven precocious glomerular pathology from concomitant development of clinically apparent renal disease, strongly suggesting that BAFF overexpression works in concert with other factors to promote overt renal disease.
Stohl
William
W
Division of Rheumatology, University of Southern California Keck School of Medicine, Los Angeles 90033, USA. stohl@usc.edu
Xu
Dong
D
Kim
Kyoung Soo
KS
Koss
Michael N
MN
Jorgensen
Trine N
TN
Deocharan
Bisram
B
Metzger
Troy E
TE
Bixler
Sarah A
SA
Hong
Yeon Sik
YS
Ambrose
Christine M
CM
Mackay
Fabienne
F
Morel
Laurence
L
Putterman
Chaim
C
Kotzin
Brian L
BL
Kalled
Susan L
SL
D000818:Animals; D000974:Antibodies, Antinuclear / Q000276:immunology; D053264:B-Cell Activating Factor; D001402:B-Lymphocytes / Q000473:pathology; D002843:Chromatin / Q000276:immunology; D004247:DNA / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D015870:Gene Expression; D020022:Genetic Predisposition to Disease; D007074:Immunoglobulin G / Q000276:immunology; D007678:Kidney Glomerulus / Q000473:pathology; D008181:Lupus Nephritis / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D013154:Spleen / Q000473:pathology; D013601:T-Lymphocytes / Q000473:pathology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000378:metabolism
D000974:Antibodies, Antinuclear; D053264:B-Cell Activating Factor; D002843:Chromatin; D007074:Immunoglobulin G; D008565:Membrane Proteins; C505720:Tnfsf13b protein, mouse; D014409:Tumor Necrosis Factor-alpha; D004247:DNA