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. 1998 Feb 2;187(3):349-55.
doi: 10.1084/jem.187.3.349.

Selective induction of apoptosis in mature T lymphocytes by variant T cell receptor ligands

Affiliations

Selective induction of apoptosis in mature T lymphocytes by variant T cell receptor ligands

B Combadière et al. J Exp Med. .

Abstract

Activation, anergy, and apoptosis are all possible outcomes of T cell receptor (TCR) engagement. The first leads to proliferation and effector function, whereas the others can lead to partial or complete immunological tolerance. Structural variants of immunizing peptide-major histocompatibility complex molecule ligands that induce selective lymphokine secretion or anergy in mature T cells in association with altered intracellular signaling events have been described. Here we describe altered ligands for mature mouse CD4(+) T helper 1 cells that lead to T cell apoptosis by the selective expression of Fas ligand (FasL) and tumor necrosis factor (TNF) without concomitant IL-2, IL-3, or interferon gamma production. All ligands that stimulated cell death were found to induce FasL and TNF mRNA expression and TCR aggregation ("capping") at the cell surface, but did not elicit a common pattern of tyrosine phosphorylation of the TCR-associated signal transduction chains. Thus, TCR ligands that uniquely trigger T cell apoptosis without inducing cytokines that are normally associated with activation can be identified.

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Figures

Figure 1
Figure 1
(A) Variant ligands induce apoptosis of CD4+ Th1 cells without the accompanying production of IL-2, IL-3, or IFN-γ. (B–D) Dose-response analyses of cycling A.E7 cells stimulated by P13.9 APCs incubated with PCC (88–104) WT peptide (B), variant peptide R99 (C), or variant peptide Y99 (D). T cell apoptosis (solid square), IL-2 (diamond), IL-3 (circle), and IFN-γ (triangle) production in cycling A.E7 cells was measured after stimulation for 24 h with P13.9 APCs in the presence of the indicated concentrations of WT peptide or variant analogues. All values are expressed as a percentage of the response obtained with 100 μM of the WT peptide. The actual 100% maximal values were as follows: apoptosis, 55% dead cells at 24 h; IL-2, 1.4 ng/ml; IL-3, ⩾250 ng/ml; IFN-γ, 120 ng/ml. All error bars are shown and represent one SD from the mean.
Figure 2
Figure 2
Induction of T cell death by partial agonists is mediated by both the Fas and TNF pathways. (Left) mRNA expression by semiquantitative RT-PCR analysis of β-actin, IL-2, Fas-L, TNF-α, and Bcl-X in cycling A.E7 cells stimulated with variant or WT ligands. Cycling A.E7 cells were stimulated for 2 h with P13.9 APCs preincubated with either medium (no Ag) or 100 μM of the WT or variant peptides as indicated. Dilutions of the RT product were pretested to ensure that the PCR reaction was in the linear range. (Right) Fas-L and TNF blocking of variant ligand-induced cell death of A.E7 cells. Cycling A.E7 cells were stimulated with APCs prepulsed with 2.5 nM WT, 100 μM C99, or 100 μM Y99 peptides, in medium alone or in the presence of either Fas-Fc (10 μg/ml), TNFR-Fc (10 μg/ml), or both Fas-Fc and TNFR-Fc as indicated. A.E7 cell death was measured as described in Materials and Methods and data are expressed as the percentage of dead cells. In control experiments, Fas-Fc and TNFR-Fc alone did not induce proliferation or apoptosis. Error bars represent one SD of the mean.
Figure 3
Figure 3
Effect of variant peptide stimulation on early tyrosine phosphorylation in cycling A.E7 cells. Tyrosine phosphorylation of major protein species (indicated on left) coprecipitating with CD3-ε (A), ZAP-70 (B), or TCR-ζ (C), revealed by immunoprecipitation followed by SDS-PAGE and phosphotyrosine immunoblotting. For each lane, 107 cycling A.E7 cells were stimulated for 10 min with 5 × 106 P13.9 APCs prepulsed with the indicated peptides. The arrowhead in C identifies a 55–60-kD phosphorylated protein coprecipitating with ζ after stimulation with C99 or Y99, the only two variants capable of inducing A.E7 cell death. The anti-ζ antiserum used here preferentially precipitates the p21 form of phospho-ζ, resulting in underdetection of the p23 species (C). SDS-PAGE was performed on a 12% gel under reducing conditions. The migration of prestained molecular weight markers is indicated on the right. B–D are from the same experiment, whereas A is from a separate experiment.
Figure 4
Figure 4
Variant TCR ligands that induce programmed cell death promote TCR aggregation. Cycling A.E7 cells were stimulated with P13.9 APCs pulsed with medium alone (NP) or with the indicated peptides at 100 μM for 5 min at 37°C. Cells were stained with fluoresceinated anti-CD3 Ab (PharMingen) (left) and Texas red conjugated–X phalloidin (right). Slides were analyzed by fluorescence microscopy. Arrows indicate TCR or actin aggregation. Small cells are A.E7 T cells (T) and larger cells are APCs.

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References

    1. Evavold BD, Sloan LJ, Allen PM. Tickling the TCR: selective T-cell functions stimulated by altered peptide ligands. Immunol Today. 1993;14:602–609. - PubMed
    1. Sloan-Lancaster J, Shaw AS, Rothbard JB, Allen PM. Partial T cell signaling: altered phospho-zeta and lack of ZAP-70 recruitment in APL-induced T cell anergy. Cell. 1994;79:913–922. - PubMed
    1. Madrenas J, Wange RL, Wang JL, Isakov N, Samelson LE, Germain RN. Zeta phosphorylation without ZAP-70 activation induced by TCR antagonists or partial agonists. Science. 1995;267:515–518. - PubMed
    1. Jameson SC, Bevan MJ. T cell receptor antagonists and partial agonists. Immunity. 1995;2:1–11. - PubMed
    1. Madrenas J, Germain RN. Variant TCR ligands: new insights into the molecular basis of antigen-dependent signal transduction and T cell activation. Semin Immunol. 1996;8:83–101. - PubMed

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