Low level exposure to inorganic mercury interferes with B cell receptor signaling in transitional type 1 B cells
- Department of Immunology, Microbiology and Biochemistry, Wayne State University, Detroit, MI (United States)
- Department of Environmental Medicine, University of Rochester, Rochester, NY (United States)
Mercury (Hg) has been implicated as a factor contributing to autoimmune disease in animal models and humans. However the mechanism by which this occurs has remained elusive. Since the discovery of B cells it has been appreciated by immunologists that during the normal course of B cell development, some immature B cells must be generated that produce immunoglobulin reactive to self-antigens (auto-antibodies). However in the course of normal development, the vast majority of immature auto-reactive B cells are prevented from maturing by processes collectively known as tolerance. Autoimmune disease arises when these mechanisms of tolerance are disrupted. In the B cell compartment, it is firmly established that tolerance depends in part upon negative selection of self-reactive immature (transitional type 1) B cells. In these cells negative selection depends upon signals generated by the B Cell Receptor (BCR), in the sense that those T1 B cells who's BCRs most strongly bind to, and so generate the strongest signals to self-antigens are neutralized. In this report we have utilized multicolor phosphoflow cytometry to show that in immature T1 B cells Hg attenuates signal generation by the BCR through mechanisms that may involve Lyn, a key tyrosine kinase in the BCR signal transduction pathway. We suggest that exposure to low, environmentally relevant levels of Hg, disrupts tolerance by interfering with BCR signaling in immature B cells, potentially leading to the appearance of mature auto-reactive B cells which have the ability to contribute to auto-immune disease. - Highlights: • Hg{sup 2+} interferes with BCR-mediated activation of ERK in immature T1 B cells. • Hg{sup 2+} acts upstream of ERK. • BCR mediated activation of Syk and the CD79a ITAM are attenuated in immature T1 B cells by Hg{sup 2+}. • The mechanism whereby which Hg{sup 2+} affects Syk and CD7a activation involves the tyrosine phosphokinase Lyn.
- OSTI ID:
- 22722910
- Journal Information:
- Toxicology and Applied Pharmacology, Journal Name: Toxicology and Applied Pharmacology Vol. 330; ISSN TXAPA9; ISSN 0041-008X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Spleen tyrosine kinase mediates high glucose-induced transforming growth factor-{beta}1 up-regulation in proximal tubular epithelial cells
Ikaros limits follicular B cell activation by regulating B cell receptor signaling pathways