An intrinsic B-cell defect supports autoimmunity in New Zealand black chromosome 13 congenic mice.
Introgression of a New Zealand Black (NZB) chromosome 13 interval onto a C57BL/6 (B6) background (B6.NZBc13) is sufficient to produce many hallmarks of lupus, including high-titre anti-chromatin antibody production, abnormal B- and T-cell activation, and renal disease. In this study we sought to characterize the immune defects leading to these abnormalities. By generating hematopoietic chimeras and BCR transgenic mice, we show that the congenic autoimmune phenotype can be transferred by BM cells and requires the presence of autoreactive B cells. Using the hen egg white lysozyme immunoglobulin transgenic mouse model, we demonstrate that B-cell anergy, deletion, and receptor editing are intact. Nevertheless, congenic B cells exhibit altered peripheral B-cell selection, as demonstrated by enhanced survival and activation of endogenous B cells with autoreactivity to chromatin and Sm/ribonucleoprotein. Given the autoantibody specificities to nuclear antigens, TLR signalling was assessed. B6.NZBc13 B cells were hyper-responsive to poly(I:C), a TLR3 ligand, demonstrating enhanced proliferation and survival as compared to B6 B cells. Our findings indicate the presence of an intrinsic B-cell defect on NZB chromosome 13 that results in hyper-responsiveness to a dsRNA analogue and implicates its potential supporting role in the generation of autoimmunity in B6.NZBc13 mice.
Arthritis Centre of Excellence, Toronto Western Research Institute, Toronto, ON, Canada.
Christina
C
Loh
Evelyn
E
Pau
Nan-Hua
NH
Chang
Joan E
JE
Wither
D000818:Animals; D020296:Animals, Congenic / Q000276:immunology; D000974:Antibodies, Antinuclear / Q000276:immunology / Q000378:metabolism; D015551:Autoimmunity / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D016026:Bone Marrow Transplantation; D002452:Cell Count; D002454:Cell Differentiation / Q000276:immunology; D049109:Cell Proliferation; D002470:Cell Survival / Q000276:immunology; D033481:Chromosomes, Mammalian / Q000235:genetics*; D017635:Clonal Anergy / Q000276:immunology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology; D005260:Female; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008814:Mice, Inbred NZB; D008822:Mice, Transgenic; D009113:Muramidase / Q000276:immunology; D011070:Poly I-C / Q000276:immunology; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D013154:Spleen / Q000276:immunology / Q000473:pathology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology; D051196:Toll-Like Receptor 3 / Q000378:metabolism; D018183:Transplantation Chimera / Q000276:immunology
D000974:Antibodies, Antinuclear; D011947:Receptors, Antigen, B-Cell; C519703:TLR3 protein, mouse; D051196:Toll-Like Receptor 3; C421864:hen egg lysozyme; D009113:Muramidase; D011070:Poly I-C