RESUMEN
Dedicator of cytokinesis (DOCK) proteins play a central role in actin cytoskeleton regulation. This is highlighted by the DOCK2 and DOCK8 deficiencies leading to actinopathies and immune deficiencies. DOCK8 and DOCK11 activate CDC42, a Rho-guanosine triphosphate hydrolases involved in actin cytoskeleton dynamics, among many cellular functions. The role of DOCK11 in human immune disease has been long suspected but, to the best of our knowledge, has never been described to date. We studied 8 male patients, from 7 unrelated families, with hemizygous DOCK11 missense variants leading to reduced DOCK11 expression. The patients were presenting with early-onset autoimmunity, including cytopenia, systemic lupus erythematosus, skin, and digestive manifestations. Patients' platelets exhibited abnormal ultrastructural morphology and spreading as well as impaired CDC42 activity. In vitro activated T cells and B-lymphoblastoid cell lines from patients exhibited aberrant protrusions and abnormal migration speed in confined channels concomitant with altered actin polymerization during migration. Knock down of DOCK11 recapitulated these abnormal cellular phenotypes in monocytes-derived dendritic cells and primary activated T cells from healthy controls. Lastly, in line with the patients' autoimmune manifestations, we also observed abnormal regulatory T-cell (Treg) phenotype with profoundly reduced FOXP3 and IKZF2 expression. Moreover, we found reduced T-cell proliferation and impaired STAT5B phosphorylation upon interleukin-2 stimulation of the patients' lymphocytes. In conclusion, DOCK11 deficiency is a new X-linked immune-related actinopathy leading to impaired CDC42 activity and STAT5 activation, and is associated with abnormal actin cytoskeleton remodeling as well as Treg phenotype, culminating in immune dysregulation and severe early-onset autoimmunity.
Asunto(s)
Enfermedades del Sistema Inmune , Síndromes de Inmunodeficiencia , Humanos , Masculino , Citoesqueleto de Actina/metabolismo , Autoinmunidad , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Enfermedades del Sistema Inmune/metabolismo , Síndromes de Inmunodeficiencia/complicaciones , Síndromes de Inmunodeficiencia/genética , Linfocitos T ReguladoresRESUMEN
TITLE: L9, un nouvel anticorps monoclonal prometteur contre le paludisme. ABSTRACT: Dans le cadre de leur module d'analyse scientifique, des étudiants de la promotion 2020-2021 des Master 2 « Immunologie Translationnelle et Biothérapies ¼ (ITB) et « Immunologie Intégrative et Systémique ¼ (I2S) (Mention Biologie Moléculaire et Cellulaire, Parcours Immunologie, Sorbonne Université) se sont penchés sur la littérature et ont pris la plume pour partager avec les lecteurs de m/s quelques-uns des faits marquants de l'actualité en immunologie. Voici une sélection de quelques-unes de ces nouvelles, illustrant la large palette des axes de recherche en cours sur les mécanismes physiopathologiques des maladies infectieuses, auto-immunes, inflammatoires et tumorales et sur le développement d'immunothérapies pour le traitement de ces maladies.
