Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system1,2. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining an immunologically unique status remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous regulatory self-peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these regulatory self-peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of regulatory self-peptides diminished. Upon boosting the presentation of these regulatory self-peptides, a population of suppressor CD4+ T cells could be expanded, controlling CNS autoimmunity in a CTLA-4 and TGF dependent manner. This unexpected discovery of CNS-derived autoimmune self-peptides may be the molecular key adapting the CNS to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system1,2. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining an immunologically unique status remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous regulatory self-peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these regulatory self-peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of regulatory self-peptides diminished. Upon boosting the presentation of these regulatory self-peptides, a population of suppressor CD4+ T cells could be expanded, controlling CNS autoimmunity in a CTLA-4 and TGF dependent manner. This unexpected discovery of CNS-derived autoimmune self-peptides may be the molecular key adapting the CNS to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system1,2. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining an immunologically unique status remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous regulatory self-peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these regulatory self-peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of regulatory self-peptides diminished. Upon boosting the presentation of these regulatory self-peptides, a population of suppressor CD4+ T cells could be expanded, controlling CNS autoimmunity in a CTLA-4 and TGF dependent manner. This unexpected discovery of CNS-derived autoimmune self-peptides may be the molecular key adapting the CNS to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
Project description:The central nervous system (CNS), despite the presence of strategically positioned anatomical barriers designed to protect it, is not entirely isolated from the immune system. In fact, it remains physically connected to and can be influenced by the peripheral immune system. How the CNS retains such responsiveness while maintaining “immune privilege” remains an outstanding conundrum. In searching for molecular cues that derive from the CNS and allow its direct communication with the immune system, we discovered a repertoire of CNS-derived endogenous guardian peptides presented on major histocompatibility complex (MHC) II molecules at the CNS borders. During homeostasis, a preponderance of these guardian peptides were found to be bound to MHC II molecules throughout the path of lymphatic drainage from the brain to its surrounding meninges and its draining cervical lymph nodes. With neuroinflammatory disease, however, the presentation of guardian peptides was diminished. Fascinatingly, boosting the presence of these guardian peptides reinforced a population of suppressor CD4+ T cells and significantly reduced CNS autoimmune disease. This unexpected discovery of CNS-derived autoimmune guardian peptides may be the molecular key adapting the CNS to receive information and to maintain continuous dialogue with the immune system while balancing overt autoreactivity. This sheds new light on how we conceptually think about and therapeutically target neuroinflammatory and neurodegenerative diseases.
Project description:Multiple Sclerosis (MS) is a complex disease of the CNS believed to require one or more environmental triggers and is characterized by episodic formation of inflammatory demyelinating lesions in the brain and spinal cord. Gut dysbiosis is a common feature in MS and here, using enhanced and quantitative PCR detection, we show that people with MS are more likely to harbor and have higher abundance of epsilon toxin (ETX)-producing strains of Clostridium perfringens within their gut microbiome compared to healthy controls (HC). MS patient-derived isolates produce functional ETX and have a genetic architecture typical of highly conjugative plasmids. In the active immunization model of experimental autoimmune encephalomyelitis (EAE), where pertussis toxin (PTX) is used to overcome CNS immune privilege, we find that ETX can substitute for PTX in disease induction. In contrast to PTX-induced EAE, where inflammatory demyelination is largely restricted to the spinal cord, ETX-induced EAE results in multifocal demyelination in the corpus callosum, thalamus, cerebellum, brainstem, and spinal cord, more akin to the lesion distribution observed in MS. Transcriptional profiles from CNS endothelial cells reveal ETX-induced genes that are known to play a role in overcoming CNS immune privilege. Together, these findings support ETX-producing strains of C. perfringens as biologically plausible pathogens in MS to trigger inflammatory demyelination in the context of circulating myelin autoreactive lymphocytes.
Project description:To identify genes of the guard cell transkriptome of Arabidopsis thaliana enriched guard cell samples were compared with total leaf tissue. Genes of the abscisic acid and humidity response of Arabidopsis thaliana guard cells were identified by treatment with ABA-Spray and low humidity. Ost1-2 and slac1-3 mutants were compared to their wildtype. total samples analysed are 35: 4 biolocigal independent replicates of: total leaf (COL-0) vs. enriched guard cells (COL-0); ABA-sprayed enriched guard cells (gl1-1) vs. control-sprayed enriched guard cells (gl1-1); enriched guard cells (slac1-3) vs. enriched guard cells (gl1-1);guard cells (ost1-2) vs. guard cells (ler);low humidity(20%rh) treated enriched guard cells (COL-0) vs. high humidity(80%) treated enriched guard cells (COL0)
Project description:To identify genes of the guard cell transcriptome of Arabidopsis thaliana enriched guard cell samples were compared with total leaf tissue. Genes of the abscisic acid and humidity response of Arabidopsis thaliana guard cells were identified by treatment with ABA-Spray and low humidity. total samples analysed are 24: 4 biological independent replicates of: total leaf (COL-0) vs. enriched guard cells (COL-0); ABA-sprayed enriched guard cells (gl1-1) vs. control-sprayed enriched guard cells (gl1-1); low humidity (20%rh) treated enriched guard cells (COL-0) vs. high humidity (80%) treated enriched guard cells (COL-0)