1. Sialylation regulates peripheral tolerance in CD4+ T cells.
- Author
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Brennan PJ, Saouaf SJ, Van Dyken S, Marth JD, Li B, Bhandoola A, and Greene MI
- Subjects
- Animals, Autoantibodies immunology, Autoantibodies metabolism, CD4-Positive T-Lymphocytes metabolism, Flow Cytometry, Immunoprecipitation, Mice, Mice, Inbred CBA, Mice, Knockout, Mice, Transgenic, Neuraminidase metabolism, Neuraminidase pharmacology, Phosphotyrosine immunology, Phosphotyrosine metabolism, Thy-1 Antigens immunology, Thy-1 Antigens metabolism, Vibrio cholerae enzymology, CD4-Positive T-Lymphocytes immunology, Immune Tolerance physiology, Neuraminidase immunology
- Abstract
Decreased binding by the 6C10 auto-antibody serves as a unique marker for CD4+ T cell unresponsiveness after the induction of T cell tolerance in Vbeta8.1 TCR transgenic mice. We further define the nature of the epitope recognized by the 6C10 antibody to be a subset of Thy-1 bearing incompletely sialylated N-linked glycans, and furthermore, we demonstrate that tolerant CD4+ T cells have an increased degree of cell-surface sialylation. To test the significance of the altered glycosylation state identified by the 6C10 auto-antibody in the tolerant CD4+ T cell population, surface sialic acid was cleaved enzymatically. Treatment of purified peripheral CD4+ T cells with Vibrio cholerae sialidase (VCS) leads to increased 6C10 binding, significantly enhances proliferation in the tolerant CD4+ population and corrects defects in phosphotyrosine signaling observed in the tolerant CD4+ T cell. Furthermore, in vivo administration of VCS enhances proliferation in both tolerant and naive CD4+ T cell subsets. These studies suggest that sialylation of glycoproteins on the surface of the CD4+ T cell contributes to the regulation of T cell responsiveness in the tolerant state.
- Published
- 2006
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