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Antigen-specific signaling by a soluble, dimeric peptide/major histocompatibility complex class II/Fc chimera leading to T helper cell type 2 differentiation.

Casares S, Zong CS, Radu DL, Miller A, Bona CA, Brumeanu TD - J. Exp. Med. (1999)

Bottom Line: Interaction between a T cell receptor (TCR) and various ligands, i.e. , anti-TCR antibodies, superantigens, peptides, or altered peptide ligands in the context of major histocompatibility complex (MHC) molecules can trigger different T helper cell (Th) effector functions.Polarization of cognate T cells toward the Th2 response occurred upon interaction of soluble DEF with TCR and CD4 molecules followed by early activation of p56(lck) and ZAP-70 tyrosine kinases, and negative signaling of the signal transducer and activator of transcription (STAT)4 pathway of Th1 differentiation.DEF-like molecules may provide a new tool to study the mechanisms of signaling toward Th2 differentiation and may also provide a potential immunotherapeutic approach to modulate autoreactive T cells toward protective Th2 immune responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, Mount Sinai School of Medicine, New York, New York 10029, USA.

ABSTRACT
Interaction between a T cell receptor (TCR) and various ligands, i.e. , anti-TCR antibodies, superantigens, peptides, or altered peptide ligands in the context of major histocompatibility complex (MHC) molecules can trigger different T helper cell (Th) effector functions. Herein, we studied the T cell response induced by a soluble, dimeric peptide/MHC class II chimera, namely hemagglutinin (HA)110-120/I-E(d)alphabeta/Fcgamma2a (DEF). We have previously demonstrated that the soluble DEF molecule binds stably and specifically to HA110-120-specific TCRs expressed by a T cell hybridoma. Administration of DEF in vivo induced differentiation of resting and activated peptide-specific T cells toward a Th2 response, as indicated by the increase of interleukin (IL)-4, IL-10, and specific immunoglobulin (Ig)G1 antibodies and decrease of IL-2, specific IgG2a antibodies, and cytotoxic T lymphocyte activity. In contrast to HA110-120 peptide presented by the DEF molecule to T cells, the nominal synthetic peptide induced a predominant Th1 response, and the PR8 virus-derived HA110-120 peptides induced a mixed Th1/Th2 response. Independent of antigen processing, soluble DEF was almost 2 logs more potent in stimulating cognate T cells than the nominal peptide. Polarization of cognate T cells toward the Th2 response occurred upon interaction of soluble DEF with TCR and CD4 molecules followed by early activation of p56(lck) and ZAP-70 tyrosine kinases, and negative signaling of the signal transducer and activator of transcription (STAT)4 pathway of Th1 differentiation. DEF-like molecules may provide a new tool to study the mechanisms of signaling toward Th2 differentiation and may also provide a potential immunotherapeutic approach to modulate autoreactive T cells toward protective Th2 immune responses.

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Effects of various blocking Abs on DEF-induced proliferative response of cognate T cells. TCR-HA spleen cells (2 × 105) from naive Tg mice were incubated with various blocking Abs (50 μg/ml), isotype control Abs (data not shown), or medium alone. 30 min later, soluble DEF or HA110-120 synthetic peptide (5 μg/ml) was added to the cultures, and thymidine incorporation was determined after 72 h as described in the text. Values represent the mean of cpm measured in triplicate wells ± SD.
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Figure 4: Effects of various blocking Abs on DEF-induced proliferative response of cognate T cells. TCR-HA spleen cells (2 × 105) from naive Tg mice were incubated with various blocking Abs (50 μg/ml), isotype control Abs (data not shown), or medium alone. 30 min later, soluble DEF or HA110-120 synthetic peptide (5 μg/ml) was added to the cultures, and thymidine incorporation was determined after 72 h as described in the text. Values represent the mean of cpm measured in triplicate wells ± SD.

Mentions: We previously demonstrated that DEF binds stably and specifically to 14.3d TCR-α/β, which recognizes HA110-120 peptide in the context of class II I-Edαβ molecules, and this binding was efficiently inhibited by anti-TCR clonotypic 6.5.2 mAb 20. We also showed that soluble DEF binds to FcγRIIβ on the surfaces of APCs 20. Herein, we investigated the role of DEF on the HA110-120–specific response upon its interaction with TCR, CD4, and FcγRIIb. Blocking of TCR with clonotypic 6.5.2 mAb or CD4 with GK1.5 mAb inhibited DEF-induced proliferation of TCR-HA Tg spleen cells. We and others have found that soluble 6.5.2 and GK1.5 mAbs have no effect on signaling T cells 2033. Therefore, inhibition of DEF-induced proliferation by these Abs was the result of hindering DEF access to TCR and CD4 molecules. In contrast, blocking of FcγRIIβ on APCs with 2.4G-2 mAb showed a weak inhibitory effect on DEF-induced proliferation (Fig. 4). This indicated that the stimulation of T cells by soluble DEF molecules depends on its interaction with TCR and CD4 molecules and is little influenced by the binding of DEF to FcγR on APCs.


Antigen-specific signaling by a soluble, dimeric peptide/major histocompatibility complex class II/Fc chimera leading to T helper cell type 2 differentiation.

Casares S, Zong CS, Radu DL, Miller A, Bona CA, Brumeanu TD - J. Exp. Med. (1999)

Effects of various blocking Abs on DEF-induced proliferative response of cognate T cells. TCR-HA spleen cells (2 × 105) from naive Tg mice were incubated with various blocking Abs (50 μg/ml), isotype control Abs (data not shown), or medium alone. 30 min later, soluble DEF or HA110-120 synthetic peptide (5 μg/ml) was added to the cultures, and thymidine incorporation was determined after 72 h as described in the text. Values represent the mean of cpm measured in triplicate wells ± SD.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2195598&req=5

Figure 4: Effects of various blocking Abs on DEF-induced proliferative response of cognate T cells. TCR-HA spleen cells (2 × 105) from naive Tg mice were incubated with various blocking Abs (50 μg/ml), isotype control Abs (data not shown), or medium alone. 30 min later, soluble DEF or HA110-120 synthetic peptide (5 μg/ml) was added to the cultures, and thymidine incorporation was determined after 72 h as described in the text. Values represent the mean of cpm measured in triplicate wells ± SD.
Mentions: We previously demonstrated that DEF binds stably and specifically to 14.3d TCR-α/β, which recognizes HA110-120 peptide in the context of class II I-Edαβ molecules, and this binding was efficiently inhibited by anti-TCR clonotypic 6.5.2 mAb 20. We also showed that soluble DEF binds to FcγRIIβ on the surfaces of APCs 20. Herein, we investigated the role of DEF on the HA110-120–specific response upon its interaction with TCR, CD4, and FcγRIIb. Blocking of TCR with clonotypic 6.5.2 mAb or CD4 with GK1.5 mAb inhibited DEF-induced proliferation of TCR-HA Tg spleen cells. We and others have found that soluble 6.5.2 and GK1.5 mAbs have no effect on signaling T cells 2033. Therefore, inhibition of DEF-induced proliferation by these Abs was the result of hindering DEF access to TCR and CD4 molecules. In contrast, blocking of FcγRIIβ on APCs with 2.4G-2 mAb showed a weak inhibitory effect on DEF-induced proliferation (Fig. 4). This indicated that the stimulation of T cells by soluble DEF molecules depends on its interaction with TCR and CD4 molecules and is little influenced by the binding of DEF to FcγR on APCs.

Bottom Line: Interaction between a T cell receptor (TCR) and various ligands, i.e. , anti-TCR antibodies, superantigens, peptides, or altered peptide ligands in the context of major histocompatibility complex (MHC) molecules can trigger different T helper cell (Th) effector functions.Polarization of cognate T cells toward the Th2 response occurred upon interaction of soluble DEF with TCR and CD4 molecules followed by early activation of p56(lck) and ZAP-70 tyrosine kinases, and negative signaling of the signal transducer and activator of transcription (STAT)4 pathway of Th1 differentiation.DEF-like molecules may provide a new tool to study the mechanisms of signaling toward Th2 differentiation and may also provide a potential immunotherapeutic approach to modulate autoreactive T cells toward protective Th2 immune responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, Mount Sinai School of Medicine, New York, New York 10029, USA.

ABSTRACT
Interaction between a T cell receptor (TCR) and various ligands, i.e. , anti-TCR antibodies, superantigens, peptides, or altered peptide ligands in the context of major histocompatibility complex (MHC) molecules can trigger different T helper cell (Th) effector functions. Herein, we studied the T cell response induced by a soluble, dimeric peptide/MHC class II chimera, namely hemagglutinin (HA)110-120/I-E(d)alphabeta/Fcgamma2a (DEF). We have previously demonstrated that the soluble DEF molecule binds stably and specifically to HA110-120-specific TCRs expressed by a T cell hybridoma. Administration of DEF in vivo induced differentiation of resting and activated peptide-specific T cells toward a Th2 response, as indicated by the increase of interleukin (IL)-4, IL-10, and specific immunoglobulin (Ig)G1 antibodies and decrease of IL-2, specific IgG2a antibodies, and cytotoxic T lymphocyte activity. In contrast to HA110-120 peptide presented by the DEF molecule to T cells, the nominal synthetic peptide induced a predominant Th1 response, and the PR8 virus-derived HA110-120 peptides induced a mixed Th1/Th2 response. Independent of antigen processing, soluble DEF was almost 2 logs more potent in stimulating cognate T cells than the nominal peptide. Polarization of cognate T cells toward the Th2 response occurred upon interaction of soluble DEF with TCR and CD4 molecules followed by early activation of p56(lck) and ZAP-70 tyrosine kinases, and negative signaling of the signal transducer and activator of transcription (STAT)4 pathway of Th1 differentiation. DEF-like molecules may provide a new tool to study the mechanisms of signaling toward Th2 differentiation and may also provide a potential immunotherapeutic approach to modulate autoreactive T cells toward protective Th2 immune responses.

Show MeSH
Related in: MedlinePlus