50 research outputs found
Naive CD8 T-cells initiate spontaneous autoimmunity to a sequestered model antigen of the central nervous system
No full textIn multiple sclerosis, CD8 T-cells are thought play a key pathogenetic role, but mechanistic evidence from rodent models is limited. Here, we have tested the encephalitogenic potential of CD8 T-cells specific for the model antigen ovalbumin (OVA) sequestered in oligodendrocytes as a cytosolic molecule. We show that in these ‘ODC-OVA’ mice, the neo-self antigen remains invisible to CD4 cells expressing the OVA-specific OT-II receptor. In contrast, OVA is accessible to naïve CD8 T-cells expressing the OT-I T-cell receptor, during the first 10 days of life, resulting in antigen release into the periphery. Introduction of OT-I as a second transgene leads to fulminant demyelinating experimental autoimmune encephalomyelitis with multiple sclerosis-like lesions, affecting cerebellum, brainstem, optic nerve and spinal cord. OVA-transgenic oligodendrocytes activate naïve OT-I cells in vitro, and both major histocompatibility complex class I expression and the OT-I response are further up-regulated by interferon-γ (IFN-γ). Release of IFN-γ into the circulation of ODC-OVA/OT-I double transgenic mice precedes disease manifestation, and pathogenicity of OT-I cells transferred into ODC-OVA mice is largely IFN-γ dependent. In conclusion, naïve CD8 T-cells gaining access to an ‘immune-privileged’ organ can initiate autoimmunity via an IFN-γ-assisted amplification loop even if the self-antigen in question is not spontaneously released for presentation by professional antigen presenting cells.Shin-Young Na, Yi Cao, Catherine Toben, Lars Nitschke, Christine Stadelmann, Ralf Gold, Anneliese Schimpl, and Thomas Hüni
Induction of experimental autoimmune encephalomyelitis in transgenic mice expressing ovalbumin in oligodendrocytes
No full textWe have used the 5' flanking sequence of the myelin basic protein gene known to include the core promoter and a strong oligodendrocyte (ODC)-specific enhancer to target expression of the well-studied model antigen ovalbumin (OVA) to ODC in transgenic mice. OVA protein was detected in a tissue- and cell-specific manner in these "ODC-OVA" mice. Without immunization, CD4 T cells and B cells remained ignorant of the neo-self antigen expressed in the central nervous system (CNS), as indicated by unimpaired development and lack of activation of OVA/IA(b)-specific TCR transgenic T cells in these mice, and the ability to mount normal OVA-specific recall and antibody responses. Upon immunization with OVA in complete Freund's adjuvant, about half of the transgenic mice developed neurological symptoms characteristic of experimental autoimmune encephalomyelitis (EAE). Mononuclear infiltrates in the brain and spinal cord contained both macrophages and T cells, similar to classical models of EAE induced by immunization with CNS antigens in adjuvant. The wealth of immunological reagents available to study and manipulate the OVA-specific response should make this new model useful for the investigation of components and mechanisms involved in CNS-specific autoimmunity.Yi Cao, Catherine Toben, Shin-Young Na, Kirsten Stark, Lars Nitschke, Alan Peterson, Ralf Gold, Anneliese Schimpl, and Thomas Hüni
Impaired thymopoietic potential of immature CD3–CD4+CD8– T cell precursors from SIV-infected rhesus monkeys
No full textEarly phenotypic and functional alterations in lymphocytes from simian immunodeficiency virus infected macaques
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Inhibition of in vitro Immune Response by Treatment of Spleen Cell Suspensions with Anti-θ Serum
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