1. B7-H1 shapes T-cell-mediated brain endothelial cell dysfunction and regional encephalitogenicity in spontaneous CNS autoimmunity.
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Klotz, Luisa, Kuzmanov, Ivan, Hucke, Stephanie, Gross, Catharina C., Posevitz, Vilmos, Dreykluft, Angela, Schulte-Mecklenbeck, Andreas, Janoschka, Claudia, Lindner, Maren, Herold, Martin, Schwab, Nicholas, Ludwig-Portugall, Isis, Kurts, Christian, Meuth, Sven G., Kuhlmann, Tanja, and Wiendl, Heinz
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MULTIPLE sclerosis ,MYELIN basic protein ,T cells ,DEMYELINATION ,BLOOD-brain barrier ,CARCINOGENESIS - Abstract
Molecular mechanisms that determine lesion localization or phenotype variation in multiple sclerosis are mostly unidentified. Although transmigration of activated encephalitogenic T cells across the blood-brain barrier (BBB) is a crucial step in the disease pathogenesis of CNS autoimmunity, the consequences on brain endothelial barrier integrity upon interaction with such T cells and subsequent lesion formation and distribution are largely unknown. We made use of a transgenic spontaneous mouse model of CNS autoimmunity characterized by inflammatory demyelinating lesions confined to optic nerves and spinal cord (OSE mice). Genetic ablation of a single immune-regulatory molecule in this model [i.e., B7-homolog 1 (B7-H1, PD-L1)] not only significantly increased incidence of spontaneous CNS autoimmunity and aggravated disease course, especially in the later stages of disease, but also importantly resulted in encephalitogenic T-cell infiltration and lesion formation in normally unaffected brain regions, such as the cerebrum and cerebellum. Interestingly, B7-H1 ablation on myelin oligodendrocyte glycoprotein-specific CD4
+ T cells, but not on antigen-presenting cells, amplified T-cell effector functions, such as IFN-γ and granzyme B production. Therefore, these T cells were rendered more capable of eliciting cell contact-dependent brain endothelial cell dysfunction and increased barrier permeability in an in vitro model of the BBB. Our findings suggest that a single immuneregulatory molecule on T cells can be ultimately responsible for localized BBB breakdown, and thus substantial changes in lesion topography in the context of CNS autoimmunity. [ABSTRACT FROM AUTHOR]- Published
- 2016
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