|
|
||||||||

,
* Arthritis Centre of Excellence, Toronto Western Research Institute, Toronto, Ontario, Canada;
Department of Immunology, University of Toronto, Toronto, Ontario, Canada; and
Department of Medicine, University Health Network, Toronto, Ontario, Canada
Genetic loci on New Zealand Black (NZB) chromosome 1 play an important role in the development of lupus-like autoimmune disease. We have shown previously that C57BL/6 mice with an introgressed NZB chromosome 1 interval extending from
35 to 106 cM have significantly more severe autoimmunity than mice with a shorter interval extending from
82 to 106 cM. Comparison of the cellular phenotype in these mice revealed that both mouse strains had evidence of increased T cell activation; however, activation was more pronounced in mice with the longer interval. Mice with the longer interval also had increased B cell activation, leading us to hypothesize that there were at least two independent lupus susceptibility loci on chromosome 1. In this study, we have used mixed hemopoietic radiation chimeras to demonstrate that autoimmunity in these mice arises from intrinsic B and T cell functional defects. We further show that a T cell defect, localized to the shorter interval, leads to spontaneous activation of T cells specific for nucleosome histone components. Despite activation of self-reactive T cells in mixed chimeric mice, only chromosome 1 congenic B cells produce anti-nuclear Abs and undergo class switching, indicating impaired B cell tolerance mechanisms. In mice with the longer chromosome 1 interval, an additional susceptibility locus exacerbates autoimmune disease by producing a positive feedback loop between T and B cell activation. Thus, T and B cell defects act in concert to produce and amplify the autoimmune phenotype.
This article has been cited by other articles:
![]() |
N.-H. Chang, T. McKenzie, G. Bonventi, C. Landolt-Marticorena, P. R. Fortin, D. Gladman, M. Urowitz, and J. E. Wither Expanded Population of Activated Antigen-Engaged Cells within the Naive B Cell Compartment of Patients with Systemic Lupus Erythematosus J. Immunol., January 15, 2008; 180(2): 1276 - 1284. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |