Major histocompatibility complex class II-positive human T cell clones are nontraditional antigen-presenting cells (APCs) that are able to simultaneously present and respond to peptide or degraded antigen, but are unable to process intact protein. Although T cell presentation of peptide antigen resulted in a primary proliferative response, T cells that had been previously stimulated by T cells ...

One of the auto-antigens aberrantly targeted in Multiple sclerosis is myelin basic protein (MBP). In this study, chronic progressive multiple sclerosis (CPMS) patients receiving the experimental drug MBP8298, on a compassionate care trial, were examined before and after high dose peptide treatment for their circulating regulatory T-cell numbers and their responses to the common mitogens, phytoh...

conclusions the cd4+ and cd8+ tcr vβ gene families undergo clonal expansion in cshb patients, and cd8+ t cells play a major role in the pathogenesis of cshb. moreover, the conserved motifs and limited use of joining region genes observed in the cshb patients of this cohort indicated that similar antigenic epitopes are recognized. results the number of oligoclonal or monoclonal expansion tcr vβ ...

The Ig-like transcript (ILT)3 is crucial to the tolerogenic activity acquired by dendritic cells exposed to allospecific T suppressor (Ts) cells. We have explored the immunomodulatory property of the extracellular region of ILT3 using a cytoplasmic deletion mutant of ILT3 (ILT3delta), expressed as membrane-bound ILT3 on KG1 cells, and a rILT3-Fc fusion protein. We found that both membrane-bound...

Engagement of TCR by its ligand, the MHC/peptide complex, causes T cell activation. T cells respond positively to stimulation with agonists, and are inhibited by antagonist MHC/peptide ligands. Failure to induce proper conformational changes in the TCR or fast TCR/MHC dissociation are the leading models proposed to explain anergy induction by antagonist ligands. In this study, we demonstrate th...

Activation of naive T cells by quiescent APCs results in tolerance through deletion and anergy. The underlying basis for these distinct fates is unclear. Using clone 4 TCR transgenic animals as a source of naive CD8 T cells, we examined the requirements for peripheral deletion in vivo. Our results demonstrate that independent of the amount of Ag used for stimulation, a single dose was insuffici...

Although many self-reactive T cells are eliminated by negative selection in the thymus, some of these cells escape into the periphery, where they must be controlled by additional mechanisms. However, the molecular mechanisms underlying peripheral T cell tolerance and its maintenance remain largely undefined. In this study, we report that sirtuin 1 (Sirt1), a type III histone deacetylase, negati...