Limits...
Anergy in peripheral memory CD4(+) T cells induced by low avidity engagement of T cell receptor.

Mirshahidi S, Huang CT, Sadegh-Nasseri S - J. Exp. Med. (2001)

Bottom Line: Since memory T cells are more responsive to lower antigenic stimulation, we hypothesized that a low avidity TCR engagement may induce tolerance in memory T cells.We demonstrate that memory CD4(+) T cells can be rendered anergic by presentation of low densities of agonist peptide-major histocompatibility complex complexes in vivo.Anergy is the most likely mechanism because addition of interleukin 2-reversed anergy in specific T cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.

ABSTRACT
Induction of tolerance in self-reactive memory T cells is an important process in the prevention of autoimmune responses against peripheral self-antigens in autoimmune diseases. Although naive T cells can readily be tolerized, memory T cells are less susceptible to tolerance induction. Recently, we demonstrated that low avidity engagement of T cell receptor (TCR) by low densities of agonist peptides induced anergy in T cell clones. Since memory T cells are more responsive to lower antigenic stimulation, we hypothesized that a low avidity TCR engagement may induce tolerance in memory T cells. We have explored two antigenic systems in two transgenic mouse models, and have tracked specific T cells that are primed and show memory phenotype. We demonstrate that memory CD4(+) T cells can be rendered anergic by presentation of low densities of agonist peptide-major histocompatibility complex complexes in vivo. We rule out other commonly accepted mechanisms for induction of T cell tolerance in vivo, such as deletion, ignorance, or immunosuppression. Anergy is the most likely mechanism because addition of interleukin 2-reversed anergy in specific T cells. Moreover, cytotoxic T lymphocyte antigen (CTLA)-4 plays a critical role in the induction of anergy because we observed that there was increased surface expression of CTLA-4 on anergized T cells, and that injection of anti-CTLA-4 blocking antibody restored anergy in vivo.

Show MeSH

Related in: MedlinePlus

Low densities of agonist peptide induce anergy in memory T cells. Mice were immunized with 10 nmol of HA306–318 in CFA; mice received a second peptide injection 2 (A), 3 (B), or 5 wk later (C) with indicated doses of HA306–318 in IFA. After 9 d, draining lymph nodes were collected and restimulated with peptide in culture. Proliferative response was measured. The spectrum of induction of anergy by low densities of agonist peptide spans 3–4 logs. The experiment shown represents five independent experiments and each point represents an average of five mice. Anergized cells are unable to produce IL-2 and IFN-γ; supernatants from lymph node cell cultures stimulated with various concentration of HA306–318 were removed after 24 and 48 h of incubation and assayed by measuring proliferation of IL-2 sensitive CTLL-2 cell line (D), and ELISA for IFN-γ (E). One out of three representative experiments is shown.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2195956&req=5

Figure 3: Low densities of agonist peptide induce anergy in memory T cells. Mice were immunized with 10 nmol of HA306–318 in CFA; mice received a second peptide injection 2 (A), 3 (B), or 5 wk later (C) with indicated doses of HA306–318 in IFA. After 9 d, draining lymph nodes were collected and restimulated with peptide in culture. Proliferative response was measured. The spectrum of induction of anergy by low densities of agonist peptide spans 3–4 logs. The experiment shown represents five independent experiments and each point represents an average of five mice. Anergized cells are unable to produce IL-2 and IFN-γ; supernatants from lymph node cell cultures stimulated with various concentration of HA306–318 were removed after 24 and 48 h of incubation and assayed by measuring proliferation of IL-2 sensitive CTLL-2 cell line (D), and ELISA for IFN-γ (E). One out of three representative experiments is shown.

Mentions: To generate memory T cells, an immunogenic dose (10 nmol ∼15 μg) of HA306–318 in CFA was injected and different groups of mice received a second injection of variable doses of HA306–318 2, 3, or 5 wk later. We also tested 2 and 3 wk intervals because in vivo tracing of DR1/ HA306–318–specific T cells is not currently available 1718. Slightly lower doses of HA306–318 were used to compensate for the higher binding affinity of HA306–318 for DR1. HA306–318-DR1 complex has a dissociation half-time of 6 d at 37°C 19. Cells from the draining nodes were removed and tested in a proliferation assay 9 d later. At short intervals between CFA priming and administration of peptide in IFA, no tolerogenic effects were observed (Fig. 3a and Fig. b), consistent with the later development of memory phenotype. When low peptide doses were administered 5 wk after the initial priming we observed tolerance. Fig. 3 C depicts proliferation of cells from mice tolerized by low doses/densities of HA306–318 (0.0005–0.05 nmol) in vivo. Cells from these groups proliferated significantly less well than cells from other groups that had received peptide doses <0.0005 nmol or higher than 0.05 nmol. The in vivo doses capable of inducing unresponsiveness spanned 3–4 logs. The inverse bell-shaped pattern of unresponsiveness to a range of peptide doses resembled T cell clones 7, where densities between 1–10 peptide–DR1 complexes per APC had the greatest inhibitory effects. Similar results were observed when the time required for induction of anergy was extended to 7 and 12 wk (see Fig. 4a and Fig. b) as a further proof for the longevity of memory T cells and their susceptibility to tolerance induction by low avidity stimulation. Although in most experiments we have used draining lymph nodes isolated 9 d after tolerogenic peptide injection, tolerance was established at time points tested as early as 2 d after second peptide injection, and persisted up to 27 d, that latest time point tested (data not shown).


Anergy in peripheral memory CD4(+) T cells induced by low avidity engagement of T cell receptor.

Mirshahidi S, Huang CT, Sadegh-Nasseri S - J. Exp. Med. (2001)

Low densities of agonist peptide induce anergy in memory T cells. Mice were immunized with 10 nmol of HA306–318 in CFA; mice received a second peptide injection 2 (A), 3 (B), or 5 wk later (C) with indicated doses of HA306–318 in IFA. After 9 d, draining lymph nodes were collected and restimulated with peptide in culture. Proliferative response was measured. The spectrum of induction of anergy by low densities of agonist peptide spans 3–4 logs. The experiment shown represents five independent experiments and each point represents an average of five mice. Anergized cells are unable to produce IL-2 and IFN-γ; supernatants from lymph node cell cultures stimulated with various concentration of HA306–318 were removed after 24 and 48 h of incubation and assayed by measuring proliferation of IL-2 sensitive CTLL-2 cell line (D), and ELISA for IFN-γ (E). One out of three representative experiments is shown.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2195956&req=5

Figure 3: Low densities of agonist peptide induce anergy in memory T cells. Mice were immunized with 10 nmol of HA306–318 in CFA; mice received a second peptide injection 2 (A), 3 (B), or 5 wk later (C) with indicated doses of HA306–318 in IFA. After 9 d, draining lymph nodes were collected and restimulated with peptide in culture. Proliferative response was measured. The spectrum of induction of anergy by low densities of agonist peptide spans 3–4 logs. The experiment shown represents five independent experiments and each point represents an average of five mice. Anergized cells are unable to produce IL-2 and IFN-γ; supernatants from lymph node cell cultures stimulated with various concentration of HA306–318 were removed after 24 and 48 h of incubation and assayed by measuring proliferation of IL-2 sensitive CTLL-2 cell line (D), and ELISA for IFN-γ (E). One out of three representative experiments is shown.
Mentions: To generate memory T cells, an immunogenic dose (10 nmol ∼15 μg) of HA306–318 in CFA was injected and different groups of mice received a second injection of variable doses of HA306–318 2, 3, or 5 wk later. We also tested 2 and 3 wk intervals because in vivo tracing of DR1/ HA306–318–specific T cells is not currently available 1718. Slightly lower doses of HA306–318 were used to compensate for the higher binding affinity of HA306–318 for DR1. HA306–318-DR1 complex has a dissociation half-time of 6 d at 37°C 19. Cells from the draining nodes were removed and tested in a proliferation assay 9 d later. At short intervals between CFA priming and administration of peptide in IFA, no tolerogenic effects were observed (Fig. 3a and Fig. b), consistent with the later development of memory phenotype. When low peptide doses were administered 5 wk after the initial priming we observed tolerance. Fig. 3 C depicts proliferation of cells from mice tolerized by low doses/densities of HA306–318 (0.0005–0.05 nmol) in vivo. Cells from these groups proliferated significantly less well than cells from other groups that had received peptide doses <0.0005 nmol or higher than 0.05 nmol. The in vivo doses capable of inducing unresponsiveness spanned 3–4 logs. The inverse bell-shaped pattern of unresponsiveness to a range of peptide doses resembled T cell clones 7, where densities between 1–10 peptide–DR1 complexes per APC had the greatest inhibitory effects. Similar results were observed when the time required for induction of anergy was extended to 7 and 12 wk (see Fig. 4a and Fig. b) as a further proof for the longevity of memory T cells and their susceptibility to tolerance induction by low avidity stimulation. Although in most experiments we have used draining lymph nodes isolated 9 d after tolerogenic peptide injection, tolerance was established at time points tested as early as 2 d after second peptide injection, and persisted up to 27 d, that latest time point tested (data not shown).

Bottom Line: Since memory T cells are more responsive to lower antigenic stimulation, we hypothesized that a low avidity TCR engagement may induce tolerance in memory T cells.We demonstrate that memory CD4(+) T cells can be rendered anergic by presentation of low densities of agonist peptide-major histocompatibility complex complexes in vivo.Anergy is the most likely mechanism because addition of interleukin 2-reversed anergy in specific T cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.

ABSTRACT
Induction of tolerance in self-reactive memory T cells is an important process in the prevention of autoimmune responses against peripheral self-antigens in autoimmune diseases. Although naive T cells can readily be tolerized, memory T cells are less susceptible to tolerance induction. Recently, we demonstrated that low avidity engagement of T cell receptor (TCR) by low densities of agonist peptides induced anergy in T cell clones. Since memory T cells are more responsive to lower antigenic stimulation, we hypothesized that a low avidity TCR engagement may induce tolerance in memory T cells. We have explored two antigenic systems in two transgenic mouse models, and have tracked specific T cells that are primed and show memory phenotype. We demonstrate that memory CD4(+) T cells can be rendered anergic by presentation of low densities of agonist peptide-major histocompatibility complex complexes in vivo. We rule out other commonly accepted mechanisms for induction of T cell tolerance in vivo, such as deletion, ignorance, or immunosuppression. Anergy is the most likely mechanism because addition of interleukin 2-reversed anergy in specific T cells. Moreover, cytotoxic T lymphocyte antigen (CTLA)-4 plays a critical role in the induction of anergy because we observed that there was increased surface expression of CTLA-4 on anergized T cells, and that injection of anti-CTLA-4 blocking antibody restored anergy in vivo.

Show MeSH
Related in: MedlinePlus