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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.

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Clone I is rendered unresponsive to Hb(64–76) upon exposure to 74L and live APCs. Clone I was cultured with 10 μM 74L peptide  and live DCEK cells. 1 wk later the T cells were isolated and restimulated  with APCs and Hb(64–76). Proliferation was measured by DNA incorporation of [3H]thymidine.
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Figure 2: Clone I is rendered unresponsive to Hb(64–76) upon exposure to 74L and live APCs. Clone I was cultured with 10 μM 74L peptide and live DCEK cells. 1 wk later the T cells were isolated and restimulated with APCs and Hb(64–76). Proliferation was measured by DNA incorporation of [3H]thymidine.

Mentions: Since 74L induced no proliferation, its ability to functionally activate the T cells was assessed by the induction of anergy. Clone I was incubated with 10 μM 74L peptide and live APC (DCEK). Upon restimulation with Hb(64– 76) 1 wk later, clone I demonstrated markedly decreased proliferation compared to control cultures (Fig. 2). The ability of 74L to induce anergy and upregulate CD25 expression (data not shown) indicates that 74L is a partial agonist for clone I. As expected, the culture of clone I with 10 μM Hb(64–76) and live APCs failed to induce unresponsiveness, and anergy of clone I could also be achieved using spleen cells as APCs (data not shown). Therefore, the induction of anergy by 74L is not due to the refractive period which T cells experience after antigen stimulation, nor is it dependent on the APC.


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

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

Clone I is rendered unresponsive to Hb(64–76) upon exposure to 74L and live APCs. Clone I was cultured with 10 μM 74L peptide  and live DCEK cells. 1 wk later the T cells were isolated and restimulated  with APCs and Hb(64–76). Proliferation was measured by DNA incorporation of [3H]thymidine.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2199180&req=5

Figure 2: Clone I is rendered unresponsive to Hb(64–76) upon exposure to 74L and live APCs. Clone I was cultured with 10 μM 74L peptide and live DCEK cells. 1 wk later the T cells were isolated and restimulated with APCs and Hb(64–76). Proliferation was measured by DNA incorporation of [3H]thymidine.
Mentions: Since 74L induced no proliferation, its ability to functionally activate the T cells was assessed by the induction of anergy. Clone I was incubated with 10 μM 74L peptide and live APC (DCEK). Upon restimulation with Hb(64– 76) 1 wk later, clone I demonstrated markedly decreased proliferation compared to control cultures (Fig. 2). The ability of 74L to induce anergy and upregulate CD25 expression (data not shown) indicates that 74L is a partial agonist for clone I. As expected, the culture of clone I with 10 μM Hb(64–76) and live APCs failed to induce unresponsiveness, and anergy of clone I could also be achieved using spleen cells as APCs (data not shown). Therefore, the induction of anergy by 74L is not due to the refractive period which T cells experience after antigen stimulation, nor is it dependent on the APC.

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
Related in: MedlinePlus