Shuaiwei Wang

Présence de cellules lymphoïdes innées dans le cerveau après un AVC ischémique: L'AVC ischémique déclenche l'activation de la microglie cérébrale et le recrutement continu de leucocytes, y compris les neutrophiles, les monocytes, les cellules dendritiques (DC) et les lymphocytes. Les cellules lymphoïdes innées (ILC) sont les contreparties innées des cellules T, exprimant des facteurs de transcription et des cytokines, qui sont essentiels pour le maintien de l'homéostasie et du remodelage tissulaire ainsi que pour la réparation tissulaire dans certaines circonstances. Cependant, leur rôle dans les attaques cérébrales ischémiques reste inconnue. Dans la thèse, nous avons induit un modèle d'accident vasculaire cérébral photothrombotique en activant par la lumière le Rose Bengal injecté de et nous avons découvert que les cellules NK, les ILC1, les ILC2 et les ILC3 étaient recrutées dans la lésion d'AVC comme observé par analyse d'imagerie confocale et 3D. Nous avons par la suite observé que les membres de la famille ILC s’accumulent progressivement dans le cerveau, la majorité de ces cellules sont des cellules NK et des ILC1. En outre, l'augmentation des cellules NK dans le cerveau atteint est causée par un afflux mais pas par une prolifération in situ.Grâce à l’utilisation du modèle murin Cdh5CreERT2 ; Cxcl12 fl et Ncr1iCre ; Cxcr4fl, nous avons observé que l’axe CXCL12-CXCR4 induit la migration des cellules NK dans le cerveau atteint d'accident vasculaire cérébral ischémique. Pour étudier les déficits neurologiques de ces souris atteintes d’AVC et le rôle des cellules NK, des expériences de “beam walk” ont été mises en place. Les souris NK déficientes apparaissent avoir le plus de déficits neurologiques.

Nociceptors are primary afferent neurons that sense noxious stimuli. They can be activated by tissue injury as well as the accompanying local immune response. We have shown that following nerve injury in mice, cytotoxic Natural Killer (NK) cells infiltrate the peripheral nerve where they interact with stress-induced ligands of the activating receptor NKG2D ( Klrk1 ). However, the diversity and specificity of NKG2D receptor ligands among sensory neuron subtypes, and translation of this mechanism to human cells, remains unknown. We used dorsal root ganglion (DRG) neurons cultured from C57BL/6J mice of both sexes with fluorescently labelled sensory neuron lines ( Scn10a , Mrgprd , Calca , Trpv1 , Th , Thy1 ), as well as human induced pluripotent stem cell-derived (hiPSCd)-sensory neurons after laser ablation, as in vitro models of axonal injury. We assessed the expression of NKG2D ligands by quantitative polymerase chain reaction (PCR) corroborated by publicly available RNA sequencing datasets and validated with single-cell PCR. Recombinant NKG2D receptor proteins were used in live cell-based assays to reveal the subcellular membrane localisation of NKG2D ligands with quantification by semi-automated image analysis. Functional interactions between human NK cells and sensory neurons were confirmed with co-cultures in microfluidic devices. We show that NKG2D ligands are expressed exclusively in unmyelinated DRG neurons after injury. Soluble mouse NKG2D receptors bound to puncta along distal neurites of injured axons enriched predominantly in Mrgprd -expressing non-peptidergic nociceptors. We observed low-level binding of soluble human NKG2D receptors to neurites of hiPSCd sensory neurons that increased after axonal laser ablation. Degeneration of hiPSCd sensory neurites by interleukin (IL-2) primed human NK cells was prevented by an NKG2D blocking antibody. The induction and enrichment of functional NKG2D receptor ligands selectively on pathological nerve fibres could aid the diagnosis of peripheral neuropathy in chronic pain conditions, and sheds new light on the potential role of nociceptive neurons in regulating the local tissue immune microenvironment.

Nociceptors are primary afferent neurons that sense noxious stimuli. They can be activated by tissue injury as well as the accompanying local immune response. We have shown that following nerve injury in mice cytotoxic Natural Killer (NK) cells infiltrate the peripheral nerve and interact with stress-induced ligands of the activating receptor NKG2D ( Klrk1 ). However, the diversity and specificity of NKG2D receptor ligands among sensory neuron subtypes, and translation of this mechanism to humans, remains unknown. We used dorsal root ganglion (DRG) neurons cultured from C57BL/6J mice of both sexes with fluorescently-labelled sensory neuron lineages ( Scn10a , Mrgprd, Calca, Trpv1 , Th , Thy1 ), as well as human induced pluripotent stem cell derived (hiPSCd)-sensory neurons after laser ablation, as in vitro models of axonal injury. We assessed expression of NKG2D ligands by quantitative polymerase chain reaction (PCR) corroborated by publicly available RNA sequencing datasets and validated with single-cell PCR. Recombinant NKG2D receptor proteins in live cell-based assays were used to reveal the subcellular membrane localisation of NKG2D ligands with quantification by a semi-automated image analysis. Functional interactions between human NK cells and sensory neurons were confirmed with co-cultures in microfluidic devices. We show that NKG2D ligands are expressed exclusively in unmyelinated DRG neurons after injury. NKG2D-receptors bound to puncta along distal neurites of injured axons enriched predominantly in Mrgprd -expressing non-peptidergic nociceptors. We observed low-level binding of human NKG2D-receptors to neurites of hiPSCd sensory neurons that increased after axonal laser ablation. Degeneration of hiPSCd sensory neurons neurites by interleukin (IL-2) primed human NK cells was prevented by an NKG2D blocking antibody. The induction and enrichment of functional NKG2D receptor ligands selectively on pathological nerve fibres could aid the diagnosis of peripheral neuropathy in chronic pain conditions, and sheds new light on the potential role of nociceptive neurons in regulating the local tissue immune microenvironment.

Background: The innate lymphoid cell (ILC) family consists of NK cells, ILC type 1, 2, 3 and lymphoid tissue inducer cells. They have been shown to play important roles in homeostasis and immune responses and are generally considered tissue resident. Not much is known about the presence of ILC members within the central nervous system and whether they are tissue resident in this organ too. Therefore, we studied the presence of all ILC members within the central nervous system and after ischemic brain insult. Methods: We used the photothrombotic ischemic lesion method to induce ischemic lesions within the mouse brain. Using whole-mount immunofluorescence imaging, we established that the ILCs were present at the rim of the lesion. We quantified the increase of all ILC members at different time-points after the ischemic lesion induction by flow cytometry. Their migration route via chemokine CXCL12 was studied by using different genetic mouse models, in which we induced deletion of Cxcl12 within the blood–brain barrier endothelium, or its receptor, Cxcr4, in the ILCs. The functional role of the ILCs was subsequently established using the beam-walk sensorimotor test. Results: Here, we report that ILCs are not resident within the mouse brain parenchyma during steady-state conditions, but are attracted towards the ischemic stroke. Specifically, we identify NK cells, ILC1s, ILC2s and ILC3s within the lesion, the highest influx being observed for NK cells and ILC1s. We further show that CXCL12 expressed at the blood–brain barrier is essential for NK cells and NKp46⁺ ILC3s to migrate toward the lesion. Complementary, Cxcr4-deficiency in NK cells prevents NK cells from entering the infarct area. Lack of NK cell migration results in a higher neurological deficit in the beam-walk sensorimotor test. Conclusions: This study establishes the lack of ILCs in the mouse central nervous system at steady-state and their migration towards an ischemic brain lesion. Our data show a role for blood–brain barrier-derived CXCL12 in attracting protective NK cells to ischemic brain lesions and identifies a new CXCL12/CXCR4-mediated component of the innate immune response to stroke.

State estimation problem in multiple target tracking usually faces high-dimensional uncertainty, including target model uncertainty, data association uncertainty, deep coupling and so on. Variational Bayesian inference provides a way to get the approximation for high-dimensional intractable problem. In this paper, we give the survey of state estimation based on variational Bayesian inference.