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Pharmacological prion protein silencing accelerates central nervous system autoimmune disease via T cell receptor signalling.

Hu W, Nessler S, Hemmer B, Eagar TN, Kane LP, Leliveld SR, Müller-Schiffmann A, Gocke AR, Lovett-Racke A, Ben LH, Hussain RZ, Breil A, Elliott JL, Puttaparthi K, Cravens PD, Singh MP, Petsch B, Stitz L, Racke MK, Korth C, Stüve O - Brain (2010)

Bottom Line: Disruption of cellular prion protein signalling augmented antigen-specific activation and proliferation, and enhanced T cell receptor signalling, resulting in zeta-chain-associated protein-70 phosphorylation and nuclear factor of activated T cells/activator protein 1 transcriptional activity.Cellular prion protein silencing with small interfering ribonucleic acid also resulted in the worsening of actively induced and adoptively transferred experimental autoimmune encephalomyelitis.Thus, central nervous system autoimmune disease was modulated at all stages of disease: the generation of the T cell effector response, the elicitation of T effector function and the perpetuation of cellular immune responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University of Texas Southwestern Medical Center at Dallas, TX, USA.

ABSTRACT
The primary biological function of the endogenous cellular prion protein has remained unclear. We investigated its biological function in the generation of cellular immune responses using cellular prion protein gene-specific small interfering ribonucleic acid in vivo and in vitro. Our results were confirmed by blocking cellular prion protein with monovalent antibodies and by using cellular prion protein-deficient and -transgenic mice. In vivo prion protein gene-small interfering ribonucleic acid treatment effects were of limited duration, restricted to secondary lymphoid organs and resulted in a 70% reduction of cellular prion protein expression in leukocytes. Disruption of cellular prion protein signalling augmented antigen-specific activation and proliferation, and enhanced T cell receptor signalling, resulting in zeta-chain-associated protein-70 phosphorylation and nuclear factor of activated T cells/activator protein 1 transcriptional activity. In vivo prion protein gene-small interfering ribonucleic acid treatment promoted T cell differentiation towards pro-inflammatory phenotypes and increased survival of antigen-specific T cells. Cellular prion protein silencing with small interfering ribonucleic acid also resulted in the worsening of actively induced and adoptively transferred experimental autoimmune encephalomyelitis. Finally, treatment of myelin basic protein(1-11) T cell receptor transgenic mice with prion protein gene-small interfering ribonucleic acid resulted in spontaneous experimental autoimmune encephalomyelitis. Thus, central nervous system autoimmune disease was modulated at all stages of disease: the generation of the T cell effector response, the elicitation of T effector function and the perpetuation of cellular immune responses. Our findings indicate that cellular prion protein regulates T cell receptor-mediated T cell activation, differentiation and survival. Defects in autoimmunity are restricted to the immune system and not the central nervous system. Our data identify cellular prion protein as a regulator of cellular immunological homoeostasis and suggest cellular prion protein as a novel potential target for therapeutic immunomodulation.

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Silencing PrPc on T cells increases ZAP-70 phosphorylation and NFAT/AP-1 reporter activity. (A) Phosphorylation of ZAP-70 and the zeta chain of the TCR/CD3 complex was increased in activated CD4+ T cells treated with Prnp-siRNA. (B) Transcription of an NFAT/AP-1 luciferase reporter was also significantly increased in activated and unstimulated T cells treated with Prnp-siRNA. In contrast, NFAT/AP-1 reporter activity was not altered in PMA/ionomycin-stimulated T cells. (C) MBP peptide AC1–11 TCR transgenic mice on a B10.PL background (I-Au) generated by Joan Goverman and coworkers developed EAE after in vivo intravenous treatment with Prnp-siRNA on Days 0, 3 and 6 of the observation period (indicated by grey arrows), but not after treatment with nonsense-siRNA. In contrast, MBP1–11 TCR transgenic mice generated by Lafaille and coworkers did not develop disease.
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Figure 6: Silencing PrPc on T cells increases ZAP-70 phosphorylation and NFAT/AP-1 reporter activity. (A) Phosphorylation of ZAP-70 and the zeta chain of the TCR/CD3 complex was increased in activated CD4+ T cells treated with Prnp-siRNA. (B) Transcription of an NFAT/AP-1 luciferase reporter was also significantly increased in activated and unstimulated T cells treated with Prnp-siRNA. In contrast, NFAT/AP-1 reporter activity was not altered in PMA/ionomycin-stimulated T cells. (C) MBP peptide AC1–11 TCR transgenic mice on a B10.PL background (I-Au) generated by Joan Goverman and coworkers developed EAE after in vivo intravenous treatment with Prnp-siRNA on Days 0, 3 and 6 of the observation period (indicated by grey arrows), but not after treatment with nonsense-siRNA. In contrast, MBP1–11 TCR transgenic mice generated by Lafaille and coworkers did not develop disease.

Mentions: Our earlier results on the effects of PrPc on antigen-specific T cell activation, proliferation and differentiation suggested that PrPc may serve as an immunomodulatory molecule and specifically that the absence of PrPc amplified TCR signalling. Zeta-chain-associated protein (ZAP)-70, a member of the protein tyrosine kinase family, is constitutively expressed in T lymphocytes. The phosphorylation of ZAP-70 and its association with the zeta chain are upstream events in the TCR signalling pathway. Prnp-siRNA, but not nonsense-siRNA, treatment was associated with increased phosphorylation of ZAP-70 and the zeta chain of the TCR/CD3 complex (Fig. 6A). There was a less pronounced but detectable increase in tyrosine phosphorylation of the ZAP-70 substrate linker of activated T cells (Fig. 6A).Figure 6


Pharmacological prion protein silencing accelerates central nervous system autoimmune disease via T cell receptor signalling.

Hu W, Nessler S, Hemmer B, Eagar TN, Kane LP, Leliveld SR, Müller-Schiffmann A, Gocke AR, Lovett-Racke A, Ben LH, Hussain RZ, Breil A, Elliott JL, Puttaparthi K, Cravens PD, Singh MP, Petsch B, Stitz L, Racke MK, Korth C, Stüve O - Brain (2010)

Silencing PrPc on T cells increases ZAP-70 phosphorylation and NFAT/AP-1 reporter activity. (A) Phosphorylation of ZAP-70 and the zeta chain of the TCR/CD3 complex was increased in activated CD4+ T cells treated with Prnp-siRNA. (B) Transcription of an NFAT/AP-1 luciferase reporter was also significantly increased in activated and unstimulated T cells treated with Prnp-siRNA. In contrast, NFAT/AP-1 reporter activity was not altered in PMA/ionomycin-stimulated T cells. (C) MBP peptide AC1–11 TCR transgenic mice on a B10.PL background (I-Au) generated by Joan Goverman and coworkers developed EAE after in vivo intravenous treatment with Prnp-siRNA on Days 0, 3 and 6 of the observation period (indicated by grey arrows), but not after treatment with nonsense-siRNA. In contrast, MBP1–11 TCR transgenic mice generated by Lafaille and coworkers did not develop disease.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2822628&req=5

Figure 6: Silencing PrPc on T cells increases ZAP-70 phosphorylation and NFAT/AP-1 reporter activity. (A) Phosphorylation of ZAP-70 and the zeta chain of the TCR/CD3 complex was increased in activated CD4+ T cells treated with Prnp-siRNA. (B) Transcription of an NFAT/AP-1 luciferase reporter was also significantly increased in activated and unstimulated T cells treated with Prnp-siRNA. In contrast, NFAT/AP-1 reporter activity was not altered in PMA/ionomycin-stimulated T cells. (C) MBP peptide AC1–11 TCR transgenic mice on a B10.PL background (I-Au) generated by Joan Goverman and coworkers developed EAE after in vivo intravenous treatment with Prnp-siRNA on Days 0, 3 and 6 of the observation period (indicated by grey arrows), but not after treatment with nonsense-siRNA. In contrast, MBP1–11 TCR transgenic mice generated by Lafaille and coworkers did not develop disease.
Mentions: Our earlier results on the effects of PrPc on antigen-specific T cell activation, proliferation and differentiation suggested that PrPc may serve as an immunomodulatory molecule and specifically that the absence of PrPc amplified TCR signalling. Zeta-chain-associated protein (ZAP)-70, a member of the protein tyrosine kinase family, is constitutively expressed in T lymphocytes. The phosphorylation of ZAP-70 and its association with the zeta chain are upstream events in the TCR signalling pathway. Prnp-siRNA, but not nonsense-siRNA, treatment was associated with increased phosphorylation of ZAP-70 and the zeta chain of the TCR/CD3 complex (Fig. 6A). There was a less pronounced but detectable increase in tyrosine phosphorylation of the ZAP-70 substrate linker of activated T cells (Fig. 6A).Figure 6

Bottom Line: Disruption of cellular prion protein signalling augmented antigen-specific activation and proliferation, and enhanced T cell receptor signalling, resulting in zeta-chain-associated protein-70 phosphorylation and nuclear factor of activated T cells/activator protein 1 transcriptional activity.Cellular prion protein silencing with small interfering ribonucleic acid also resulted in the worsening of actively induced and adoptively transferred experimental autoimmune encephalomyelitis.Thus, central nervous system autoimmune disease was modulated at all stages of disease: the generation of the T cell effector response, the elicitation of T effector function and the perpetuation of cellular immune responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University of Texas Southwestern Medical Center at Dallas, TX, USA.

ABSTRACT
The primary biological function of the endogenous cellular prion protein has remained unclear. We investigated its biological function in the generation of cellular immune responses using cellular prion protein gene-specific small interfering ribonucleic acid in vivo and in vitro. Our results were confirmed by blocking cellular prion protein with monovalent antibodies and by using cellular prion protein-deficient and -transgenic mice. In vivo prion protein gene-small interfering ribonucleic acid treatment effects were of limited duration, restricted to secondary lymphoid organs and resulted in a 70% reduction of cellular prion protein expression in leukocytes. Disruption of cellular prion protein signalling augmented antigen-specific activation and proliferation, and enhanced T cell receptor signalling, resulting in zeta-chain-associated protein-70 phosphorylation and nuclear factor of activated T cells/activator protein 1 transcriptional activity. In vivo prion protein gene-small interfering ribonucleic acid treatment promoted T cell differentiation towards pro-inflammatory phenotypes and increased survival of antigen-specific T cells. Cellular prion protein silencing with small interfering ribonucleic acid also resulted in the worsening of actively induced and adoptively transferred experimental autoimmune encephalomyelitis. Finally, treatment of myelin basic protein(1-11) T cell receptor transgenic mice with prion protein gene-small interfering ribonucleic acid resulted in spontaneous experimental autoimmune encephalomyelitis. Thus, central nervous system autoimmune disease was modulated at all stages of disease: the generation of the T cell effector response, the elicitation of T effector function and the perpetuation of cellular immune responses. Our findings indicate that cellular prion protein regulates T cell receptor-mediated T cell activation, differentiation and survival. Defects in autoimmunity are restricted to the immune system and not the central nervous system. Our data identify cellular prion protein as a regulator of cellular immunological homoeostasis and suggest cellular prion protein as a novel potential target for therapeutic immunomodulation.

Show MeSH
Related in: MedlinePlus