35 research outputs found
Tolerant CD8 T cells induced by multiple injections of peptide antigen show impaired TCR signaling and altered proliferative responses in vitro and in vivo
The mechanisms responsible for peripheral CD8 T cell tolerance to foreign Ags remain poorly understood. In this study we have characterized the state of CD8 T cell tolerance induced in F5 TCR transgenic mice by multiple peptide injections in vivo. The tolerant state of CD8 T cells is characterized by impaired proliferative responses, increased sensitivity to cell death, and failure to acquire cytotoxic effector function after in vitro antigenic challenge. In vivo monitoring of CD8 T cell proliferation using 5- carboxyfluorescein diacetate succinimidyl ester showed that a large subset of the tolerant T cell population failed to divide in response to peptide. TCR down-regulation could not account for this loss of responsiveness to Ag since recombination-activating gene-1 (RAG-1)(-/-)F5 CD8 T cell responses were similar to those of RAG-1(-/-)F5 x RAG-1(-/-)F1 T lymphocytes, which express lower levels of the transgenic TCR. Analysis of early signal transduction in tolerant CD8 T cells revealed high basal levels of cytoplasmic calcium as well as impaired calcium mobilization and tyrosine phosphorylation after cross-linking of CD3ε and CD8α. Together these data indicate that repeated exposure to soluble antigenic peptide in vivo can induce a state of functional tolerance characterized by defective TCR signaling, impaired proliferation, and increased sensitivity to cell death.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Flt3 Ligand-Generated Murine Plasmacytoid and Conventional Dendritic Cells Differ in Their Capacity to Prime Naive CD8 T Cells and to Generate Memory Cells In Vivo
In Vivo Impact of CpG1826 Oligodeoxynucleotide on CD8 T Cell Primary Responses and Survival
In Vivo Impact of CpG1826 Oligodeoxynucleotide on CD8 T Cell Primary Responses and Survival
Hyperproliferative Response of a Monoclonal Memory CD8 T Cell Population Is Characterized by an Increased Frequency of Clonogenic Precursors
Correction: CpG Promotes Cross-Presentation of Dead Cell-Associated Antigens by Pre-CD8α +
Memory CD44int CD8 T cells show increased proliferative responses and IFN-γ production following antigenic challenge in vitro
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