Clinical and multi-omics cross-phenotyping of patients with autoimmune and autoinflammatory diseases: the observational TRANSIMMUNOM protocol.

INTRODUCTION: Autoimmune and autoinflammatory diseases (AIDs) represent a socioeconomic burden as the second cause of chronic illness in Western countries. In this context, the TRANSIMMUNOM clinical protocol is designed to revisit the nosology of AIDs by combining basic, clinical and information sciences. Based on classical and systems biology analyses, it aims to uncover important phenotypes that cut across diagnostic groups so as to discover biomarkers and identify novel therapeutic targets. METHODS AND ANALYSIS: TRANSIMMUNOM is an observational clinical protocol that aims to cross-phenotype a set of 19 AIDs, six related control diseases and healthy volunteers . We assembled a multidisciplinary cohort management team tasked with (1) selecting informative biological (routine and omics type) and clinical parameters to be captured, (2) standardising the sample collection and shipment circuit, (3) selecting omics technologies and benchmarking omics data providers, (4) designing and implementing a multidisease electronic case report form and an omics database and (5) implementing supervised and unsupervised data analyses. ETHICS AND DISSEMINATION: The study was approved by the institutional review board of Pitié-Salpêtrière Hospital (ethics committee Ile-De-France 48-15) and done in accordance with the Declaration of Helsinki and good clinical practice. Written informed consent is obtained from all participants before enrolment in the study. TRANSIMMUNOM's project website provides information about the protocol (https://www.transimmunom.fr/en/) including experimental set-up and tool developments. Results will be disseminated during annual scientific committees appraising the project progresses and at national and international scientific conferences. DISCUSSION: Systems biology approaches are increasingly implemented in human pathophysiology research. The TRANSIMMUNOM study applies such approach to the pathophysiology of AIDs. We believe that this translational systems immunology approach has the potential to provide breakthrough discoveries for better understanding and treatment of AIDs. TRIAL REGISTRATION NUMBER: NCT02466217; Pre-results.

Analysis of uncoupling protein 2-deficient mice upon anaesthesia and sedation revealed a role for UCP2 in locomotion.

General anaesthesia is associated with hypothermia, oxidative stress, and immune depression. Uncoupling Protein (UCP2) is a member of the mitochondrial carrier family present in many organs including the spleen, the lung and the brain. A role of UCP2 in the activation of the inflammatory/immune cells, in the secretion of hormones, and in the excitability of neurons by regulating the production of reactive oxygen species has been discussed. Because of the side effects of anaesthesia listed above, we aimed to question the expression and the function of UCP2 during anaesthesia. Induction of anaesthesia with ketamine (20 mg/kg) or isoflurane (3.6%) and induction of sedation with the α2 adrenergic receptor agonist medetomidine (0.2 mg/kg) stimulated infiltration of immune cells in the lung and increased UCP2 protein content in the lung, in both immune and non-immune cells. UCP2 content in the lung inversely correlated with body temperature decrease induced by medetomidine treatment. Challenge of the Ucp2(-/-) mice with isoflurane and medetomidine revealed an earlier behavioral recovery phenotype. Transponder analysis of body temperature and activity showed no difference between Ucp2(-/-) and control mice in basal conditions. However, upon an acute decrease of body temperature induced by medetomidine, Ucp2(-/-) mice exhibited increased locomotion activity. Together, these results show that UCP2 is rapidly mobilized during anaesthesia and sedation in immune cells, and suggest a role of UCP2 in locomotion.

Deletion of UCP2 in iNOS deficient mice reduces the severity of the disease during experimental autoimmune encephalomyelitis.

Uncoupling protein 2 is a member of the mitochondrial anion carrier family that is widely expressed in neurons and the immune cells of humans. Deletion of Ucp2 gene in mice pre-activates the immune system leading to higher resistance toward infection and to an increased susceptibility to develop chronic inflammatory diseases as previously exemplified with the Experimental Autoimmune Encephalomyelitis (EAE), a mouse model for multiple sclerosis. Given that oxidative stress is enhanced in Ucp2-/- mice and that nitric oxide (NO) also plays a critical function in redox balance and in chronic inflammation, we generated mice deficient for both Ucp2 and iNos genes and submitted them to EAE. Mice lacking iNos gene exhibited the highest clinical score (3.4+/-0.5 p<0.05). Surprisingly, mice deficient for both genes developed milder disease with reduced immune cell infiltration, cytokines and ROS production as compared to iNos-/- mice.

Alterations in anxiety-like behavior following knockout of the uncoupling protein 2 (ucp2) gene in mice.

AIMS: Uncoupling protein 2 (UCP2) is a mitochondrial protein that reduces oxidative stress and has a protective function in chronic inflammatory diseases such as multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus. UCP2 is strongly expressed in areas implicated in the central regulation of stress and anxiety. Therefore, we compared the neuroendocrine regulation of stress responses, immunity and behavior in UCP2-deficient and wildtype C57BL/6J mice under psychological stress. MAIN METHODS: Stress was induced by social disruption (SDR) and anxiety-like behavior was examined using the elevated plus-maze (EPM). Serum corticosterone was determined by radioimmunoassay and brain neurotransmitter concentrations were analyzed by HPLC of whole brain homogenates. T cell activation and tumor necrosis factor (TNF)-α production of mitogen-activated splenocytes were determined in vitro by flow cytometry staining of CD25, CD69 and CD71 on CD4 cells, and ELISA, respectively. The influence of corticosterone on UCP2 expression of splenocytes was analyzed by Western blot. KEY FINDINGS: At baseline, UCP2-deficient mice were significantly more anxious in the EPM than wildtype mice, and this phenotype was exacerbated after SDR stress. The corticosterone response after SDR+EPM was reduced in UCP2-deficient mice compared to wildtype mice. Corticosterone in turn downregulates UCP2 expression in splenocyte cultures of wildtype mice at physiological concentrations. Dopaminergic and serotonergic turnovers were increased in UCP2-deficient mice after SDR+EPM. While T-helper cell activation-marker expression was reduced, TNF-α production was increased in UCP2-deficient mice after SDR+EPM. SIGNIFICANCE: Our study shows that UCP2 is involved in anxiety-like behavior and modulates neuroendocrine and immune responses after stress.