Les pathologies du SNC associent neurodégénérescence, troubles de la transmission et des processus neuroinflammatoires : réaction gliale et recrutement de cellules immunes. Les cellules immunes peuvent participer aux processus de souffrance neuronale et inhiber les processus de réparation comme la neurogenèse, mais peuvent également exercer des rôles neuroprotecteurs. Notre équipe a décrit que la molécule RAE-1, connue pour son rôle de ligand du récepteur activateur NKG2D exprimé par les NK, est exprimée constitutivement dans la SVZ, la zone de neurogenèse adulte qui génère des neuroblastes qui migrent vers le bulbe olfactif. De plus, RAE-1 est exprimée par les neurosphères issues de la SVZ et exerce un rôle non immun sur la prolifération cellulaire.L'objectif était de comprendre le rôle de RAE-1 et des NK en situation pathologique. J'ai étudié, en particulier, le modèle de lésion chimique des neurones olfactifs après injection de dichlobenil qui induit une mort neuronale suivie d'une réparation des réseaux neuronaux dans le bulbe olfactif. Ce modèle, connu des neurobiologistes, n'avait jamais été étudié sur le plan neuroinflammatoire. Nous avons caractérisé dans le bulbe olfactif, en RT-qPCR et cytométrie en flux multicouleur : la cinétique des processus de dé-afférentation, de ré-afférentation, de réaction gliale et le recrutement de cellules immunes. Je décris également l'induction de RAE-1 dans le bulbe olfactif, qui n'est pas liée à la présence d'une neurogenèse locale mais qui corrèle avec la prolifération microgliale et l'expression du M-CSF. Ces processus sont modifiés après un traitement à la minocycline et la déplétion des NK. Avec des modèles de culture in vitro, j'ai identifié RAE-1 comme un marqueur et un acteur de la microglie proliférative qui exerce, contrairement à la microglie non proliférative, des effets neuroprotecteurs. / CNS pathologies are characterized by neurodegeneration, neurotransmission impairment and neuroinflammation including glial reactivity and immune cells recruitment. Neuroinflammation induces neuronal loss and impairs neurogenesis but can also exerts neuroprotective effects. Our team has recently demonstrated that RAE-1 is constitutively expressed in the adult subventricular zone (SVZ), the main neurogenic niche where resident neural stem cells generate neuroblasts which migrate in chains to the olfactory bulbs, where they differentiate into interneurons. We also have reported in vitro that RAE-1 is a marker of proliferating neural stem/progenitor cells and plays a non-immune role in cell proliferation. The main objective was to understand the role of RAE-1 and NK cells in pathological condition. We mainly studied a model of chemical ablation of olfactory neurons using dichlobenil which induced neuronal loss followed by an olfactory neuronal network recovery. Neuroinflammatory processes have never been studied in this model, used by neurobiologists. Using RT-qPCR and multicolor flow cytometry, I characterized the processes of deafferentation, reafferentation, astroglia and microglia activation and the recruitment of immune cells. Moreover, RAE-1 expression was induced in the olfactory bulbs. This expression correlated with the increase of microglial cell proliferation markers and M-CSF expression. These neuroinflammatory processes were altered after NK cells depletion and minocyline treatments. Using in vitro culture models, I showed that RAE-1 is a marker and an actor of microglia proliferation. Moreover, proliferative microglia but not non proliferative cells exerts a neuroprotective effect.

Seminario de Título entregado a la Universidad de Chile en cumplimiento parcial de los requisitos para optar al Título de Ingeniera en Biotecnología Molecular. / El desarrollo de una respuesta inmune anti-tumoral requiere de la comunicación entre diferentes células del sistema inmune, así como del reconocimiento de la célula tumoral. Una vez que los Linfocitos T Citotóxicos (CTL) y las células Natural Killers (NK) reconocen la célula tumoral, forman la Sinapsis Inmunológica Citotóxica (SIC), una estructura supramolecular altamente especializada que resulta fundamental para la liberación localizada de los gránulos citotóxicos y la eliminación específica de la célula tumoral. Recientemente, se ha descrito la participación de canales Gap Junction (GJ) formados por la isoforma Cx43 (GJ-Cx43) en la actividad citotóxica de las células NK durante la SIC. A pesar de las similitudes funcionales y estructurales presentadas por la SIC mediada por las células NK y por CTL, la participación de los canales GJ-Cx43 en la sinapsis mediada por CTL aún no ha sido determinada. En este trabajo se estudió el rol de los canales GJ-Cx43 en la actividad de la SIC entre CTL obtenidos desde ratones pMEL-1 y células de melanoma murino B16F10. Primero, se evaluó la polarización de Cx43 hacia la zona de contacto entre CTL pMEL-1 y células B16F10, durante la SIC. Se determinó que Cx43 se acumula en el sitio de contacto entre estas células de manera antígeno específica y que esta polarización es dependiente de la activación de los CTL. Luego, se disminuyó la expresión de Cx43 en células B16F10 utilizando un RNA interferente contra Cx43 y luego se evaluó la participación de Cx43 en la formación de canales GJ mediante ensayos de transferencia de calceína y en la actividad citotóxica de los CTL, mediante ensayos de actividad de Granzima B (GrzB). Se observó que los CTL transfieren calceína a las células B16F10 formando canales GJ funcionales, al contrario de cuando se utilizan LT CD8+ vírgenes como células efectoras. Además, cuando se utilizaron las células B16F10 que expresan bajos niveles de Cx43 como células blanco, se observó una disminución en la transferencia de calceína y en la actividad de GrzB en comparación al control. Nuestros resultados demuestran que durante el reconocimiento citotóxico se forman canales GJ-Cx43 entre CTL y células B16F10 y que la formación de estos canales durante la SIC son importantes para la eliminación de células tumorales mediada por CTL. / Development of antitumor immune responses requires communication between different immune cells, and specific immune recognition of tumor cells. Upon tumor cell recognition, CD8+ cytotoxic T lymphocytes (CTL) and natural killer (NK) cells form the “Cytotoxic Immunological Synapse (SIC)”, a specialized molecular structure fundamental for the polarized delivery of cytotoxic granules and the specific tumor cell killing. Recently, it has been described the participation of Gap Junction Intercellular Communications formed by Connexin 43 (GJIC-Cx43) in the NK cell SIC activity. Despite that CTL and NK cells present functional and structural similarities in SIC formation, the participation of GJIC-Cx43 in CTL-mediated SIC remains unclear. In this work we studied the role of GJIC-Cx43 in the activity of SIC formed between CTL from pMEL-1 mice and B16F10 murine melanoma cells. First, we evaluated by immunofluorescence the polarization of Cx43 to contact site between CTL and B16F10 during SIC. We found that this protein localizes at the contact site of SIC and this polarization dependent on activation of CTL and is an antigenic-specific process. Then, we decrease Cx43 expression in B16F10 cells using interference RNA against Cx43 and we evaluated the participation of Cx43 in the formation of functional GJ channels by calcein transfer assay and in the cytotoxic activity of CTL by Granzyme B (GrzB) activity assay. We found that CTL transfer calcein to B16F10 forming functional GJ in contrast with when we used a naïve CD8+ T cells as an effector cells. In addition, when we used a B16F10 that express low levels of Cx43 as target cells, we observed a decrease in calcein transfer and GrzB activity in comparison to the control. Our results demonstrate that GJIC-Cx43 are formed between CTL and B16F10 during SIC, and suggest that their formation is important for tumor cells-killing by CTL

Introdução: A endometriose, condição inflamatória prevalente, associa-se a alterações da reposta imune na cavidade peritoneal e no útero. Evidências sugerem participação de mediadores inflamatórios, como as células Natural Killer e T-reguladoras na patogênese desta doença. A resposta destas células pode ser controlada pela atividade de algumas quimiocinas. O objetivo deste estudo foi avaliar a expressão gênica das quimiocinas reguladoras das células Natural Killer e T-reguladoras em endométrio tópico em lesões endometrióticas de pacientes com endometriose. Pacientes e Métodos: A expressão gênica das quimiocinas reguladoras da atividade das células Natural Killer (CXCL9, 10, 11, CXCL12, XCL1 e CX3CL1) e T reguladoras (CCL17 e CCL21) foi avaliada por meio de RTPCR no endométrio tópico e lesão endometriótica de 22 pacientes com endometriose de retossigmóide; 10 pacientes com endometriose retrocervical e no endométrio tópico de 32 mulheres sem endometriose comprovada por laparoscopia para laqueadura tubária. Resultados: Dentre as quimiocinas relacionadas às células Natural Killer, encontramos diferença estatística significativa na CX3CL1 e CXCL12, as quais foram mais expressas no foco de endometriose intestinal e retrocervical, quando comparadas ao endométrio tópico das pacientes e controles (p < 0,05). Das relacionadas às células T-reguladoras, a CCL17 foi mais expressa no endométrio tópico de pacientes com lesão em retossigmóide quando comparada aos demais grupos (p < 0,05). Conclusões: As quimiocinas CX3CL1 e CXCL12 foram mais expressas nos focos de endometriose intestinal e a CCL17 foi mais expressa no endométrio tópico de pacientes com lesão de retossigmóide. Estes resultados sugerem que as quimiocinas CX3CL1, CXCL12 e CXCL17 participam da resposta inflamatória que ocorre na endometriose pélvica / Objective: Endometriosis is a highly prevalent inflammatory condition associated with an altered immune response in the peritoneal cavity and uterus. Evidence suggests a participation of inflammatory mediators such as natural killer (NK) and T-regulatory (T-reg) cells in the pathogenesis of this disease while the response of these cells may be controlled by the activity of some chemokines. Patients and Methods: Gene expressions of the chemokines that regulate the activity of NK (CXCL9, CXCL10, CXCL11, CXCL12, XCL1 and CX3CL1) and T-reg cells (CCL17 and CCL21) were evaluated using real time polymerase chain reaction (PCR) in the eutopic and ectopic endometrium of 22 patients with bowel endometriosis, 10 patients with retrocervical endometriosis and 32 controls. Results: Of the chemokines associated with NK cells, the expression of CX3CL1 and CXCL12 was significantly greater in the foci of endometriosis (p < 0.05). Of those associated with T-reg cells, significant differences between groups were found in CCL17. In addition, CCL17 was expressed to a higher degree in the eutopic endometrium of the patients with rectosigmoid lesions when compared to the other groups (p < 0.05). Conclusions: Chemokines CX3CL1 and CXCL12 were more expressed in intestinal endometriosis and CCL17 expression was higher in eutopic endometrium of the patients with rectosigmoid lesions. These results suggest that those chemokines participate in the inflammatory response that occurs in pelvic endometriosis

Introdução: A endometriose, condição inflamatória prevalente, associa-se a alterações da reposta imune na cavidade peritoneal e no útero. Evidências sugerem participação de mediadores inflamatórios, como as células Natural Killer e T-reguladoras na patogênese desta doença. A resposta destas células pode ser controlada pela atividade de algumas quimiocinas. O objetivo deste estudo foi avaliar a expressão gênica das quimiocinas reguladoras das células Natural Killer e T-reguladoras em endométrio tópico em lesões endometrióticas de pacientes com endometriose. Pacientes e Métodos: A expressão gênica das quimiocinas reguladoras da atividade das células Natural Killer (CXCL9, 10, 11, CXCL12, XCL1 e CX3CL1) e T reguladoras (CCL17 e CCL21) foi avaliada por meio de RTPCR no endométrio tópico e lesão endometriótica de 22 pacientes com endometriose de retossigmóide; 10 pacientes com endometriose retrocervical e no endométrio tópico de 32 mulheres sem endometriose comprovada por laparoscopia para laqueadura tubária. Resultados: Dentre as quimiocinas relacionadas às células Natural Killer, encontramos diferença estatística significativa na CX3CL1 e CXCL12, as quais foram mais expressas no foco de endometriose intestinal e retrocervical, quando comparadas ao endométrio tópico das pacientes e controles (p < 0,05). Das relacionadas às células T-reguladoras, a CCL17 foi mais expressa no endométrio tópico de pacientes com lesão em retossigmóide quando comparada aos demais grupos (p < 0,05). Conclusões: As quimiocinas CX3CL1 e CXCL12 foram mais expressas nos focos de endometriose intestinal e a CCL17 foi mais expressa no endométrio tópico de pacientes com lesão de retossigmóide. Estes resultados sugerem que as quimiocinas CX3CL1, CXCL12 e CXCL17 participam da resposta inflamatória que ocorre na endometriose pélvica / Objective: Endometriosis is a highly prevalent inflammatory condition associated with an altered immune response in the peritoneal cavity and uterus. Evidence suggests a participation of inflammatory mediators such as natural killer (NK) and T-regulatory (T-reg) cells in the pathogenesis of this disease while the response of these cells may be controlled by the activity of some chemokines. Patients and Methods: Gene expressions of the chemokines that regulate the activity of NK (CXCL9, CXCL10, CXCL11, CXCL12, XCL1 and CX3CL1) and T-reg cells (CCL17 and CCL21) were evaluated using real time polymerase chain reaction (PCR) in the eutopic and ectopic endometrium of 22 patients with bowel endometriosis, 10 patients with retrocervical endometriosis and 32 controls. Results: Of the chemokines associated with NK cells, the expression of CX3CL1 and CXCL12 was significantly greater in the foci of endometriosis (p < 0.05). Of those associated with T-reg cells, significant differences between groups were found in CCL17. In addition, CCL17 was expressed to a higher degree in the eutopic endometrium of the patients with rectosigmoid lesions when compared to the other groups (p < 0.05). Conclusions: Chemokines CX3CL1 and CXCL12 were more expressed in intestinal endometriosis and CCL17 expression was higher in eutopic endometrium of the patients with rectosigmoid lesions. These results suggest that those chemokines participate in the inflammatory response that occurs in pelvic endometriosis