Limits...
Persistence of peptide-induced CD4+ T cell anergy in vitro.

Ryan KR, Evavold BD - J. Exp. Med. (1998)

Bottom Line: The anergic state was characterized by blunted proliferation and interleukin (IL) 2 production upon restimulation with Hb(64-76), and was not the result of impaired TCR/CD3 downmodulation.Interestingly, persistence of the anergic phenotype was observed despite biweekly restimulation with antigen, APCs, and IL-2.Thus, T cell unresponsiveness induced by a peptide produced a stable, persistent anergic state in a Th0 clone that was not reversible by stimulation with IL-2 or -12.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Emory University, Atlanta, Georgia 30322, USA.

ABSTRACT
Clonal T cell unresponsiveness, or anergy, has been proposed as a mechanism of peripheral tolerance in vivo, and as a potential means of curbing unwanted T cell responses. In this study, anergy was induced in a T helper cell (Th) clone reactive to hemoglobin (Hb) peptide 64-76 by coculture of the T cells with live antigen-presenting cells (APCs) and 74L, a peptide analog of Hb(64-76) that contains a single amino acid substitution of leucine for glycine at position 74, or with a low concentration of the agonist ligand. The anergic state was characterized by blunted proliferation and interleukin (IL) 2 production upon restimulation with Hb(64-76), and was not the result of impaired TCR/CD3 downmodulation. The addition of exogenous IL-12 transiently restored proliferation of the anergic lines, but removal of IL-12 from culture returned the T cells to their nonproliferative state. Interestingly, persistence of the anergic phenotype was observed despite biweekly restimulation with antigen, APCs, and IL-2. Thus, T cell unresponsiveness induced by a peptide produced a stable, persistent anergic state in a Th0 clone that was not reversible by stimulation with IL-2 or -12.

Show MeSH
Dose–response of clone I to Hb(64–76) and 74L. Clone I  was cultured with APCs and various concentrations of synthetic peptides.  Proliferation was measured by incorporation of [3H]thymidine into the  DNA of clone I.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2199180&req=5

Figure 1: Dose–response of clone I to Hb(64–76) and 74L. Clone I was cultured with APCs and various concentrations of synthetic peptides. Proliferation was measured by incorporation of [3H]thymidine into the DNA of clone I.

Mentions: Helper T cell clones were generated from lymph node cells of H-2k mice and screened for proliferative responses to Hb(64–76) and production of the cytokines IL-2, IL-4, and IFN-γ. One Th0 clone, designated clone I, was selected for further study based on its reactivity to Hb(64–76) and its elaboration of IL-2, IL-4, and IFN-γ (Fig. 1, Table 1). IL-2 production was detected by bioassay and was confirmed by the addition of neutralizing anti–IL-2 antibody to the assay. In addition, clone I produced IFN-γ (3,230 U/ml) and IL-4 (1,851 pg/ml) as determined by antigen capture ELISA. IL-4 and IFN-γ production was confirmed by reverse transcription PCR, bioassay (IL-4 only), and intracellular cytokine flow cytometry (data not shown). The combined evidence from these assays classifies clone I as a Th0.


Persistence of peptide-induced CD4+ T cell anergy in vitro.

Ryan KR, Evavold BD - J. Exp. Med. (1998)

Dose–response of clone I to Hb(64–76) and 74L. Clone I  was cultured with APCs and various concentrations of synthetic peptides.  Proliferation was measured by incorporation of [3H]thymidine into the  DNA of clone I.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199180&req=5

Figure 1: Dose–response of clone I to Hb(64–76) and 74L. Clone I was cultured with APCs and various concentrations of synthetic peptides. Proliferation was measured by incorporation of [3H]thymidine into the DNA of clone I.
Mentions: Helper T cell clones were generated from lymph node cells of H-2k mice and screened for proliferative responses to Hb(64–76) and production of the cytokines IL-2, IL-4, and IFN-γ. One Th0 clone, designated clone I, was selected for further study based on its reactivity to Hb(64–76) and its elaboration of IL-2, IL-4, and IFN-γ (Fig. 1, Table 1). IL-2 production was detected by bioassay and was confirmed by the addition of neutralizing anti–IL-2 antibody to the assay. In addition, clone I produced IFN-γ (3,230 U/ml) and IL-4 (1,851 pg/ml) as determined by antigen capture ELISA. IL-4 and IFN-γ production was confirmed by reverse transcription PCR, bioassay (IL-4 only), and intracellular cytokine flow cytometry (data not shown). The combined evidence from these assays classifies clone I as a Th0.

Bottom Line: The anergic state was characterized by blunted proliferation and interleukin (IL) 2 production upon restimulation with Hb(64-76), and was not the result of impaired TCR/CD3 downmodulation.Interestingly, persistence of the anergic phenotype was observed despite biweekly restimulation with antigen, APCs, and IL-2.Thus, T cell unresponsiveness induced by a peptide produced a stable, persistent anergic state in a Th0 clone that was not reversible by stimulation with IL-2 or -12.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Emory University, Atlanta, Georgia 30322, USA.

ABSTRACT
Clonal T cell unresponsiveness, or anergy, has been proposed as a mechanism of peripheral tolerance in vivo, and as a potential means of curbing unwanted T cell responses. In this study, anergy was induced in a T helper cell (Th) clone reactive to hemoglobin (Hb) peptide 64-76 by coculture of the T cells with live antigen-presenting cells (APCs) and 74L, a peptide analog of Hb(64-76) that contains a single amino acid substitution of leucine for glycine at position 74, or with a low concentration of the agonist ligand. The anergic state was characterized by blunted proliferation and interleukin (IL) 2 production upon restimulation with Hb(64-76), and was not the result of impaired TCR/CD3 downmodulation. The addition of exogenous IL-12 transiently restored proliferation of the anergic lines, but removal of IL-12 from culture returned the T cells to their nonproliferative state. Interestingly, persistence of the anergic phenotype was observed despite biweekly restimulation with antigen, APCs, and IL-2. Thus, T cell unresponsiveness induced by a peptide produced a stable, persistent anergic state in a Th0 clone that was not reversible by stimulation with IL-2 or -12.

Show MeSH