Role of IL-27 in Epstein-Barr virus infection revealed by IL-27RA deficiency.

Epstein-Barr virus (EBV) infection can engender severe B cell lymphoproliferative diseases1,2. The primary infection is often asymptomatic or causes infectious mononucleosis (IM), a self-limiting lymphoproliferative disorder3. Selective vulnerability to EBV has been reported in association with inherited mutations impairing T cell immunity to EBV4. Here we report biallelic loss-of-function variants in IL27RA that underlie an acute and severe primary EBV infection with a nevertheless favourable outcome requiring a minimal treatment. One mutant allele (rs201107107) was enriched in the Finnish population (minor allele frequency = 0.0068) and carried a high risk of severe infectious mononucleosis when homozygous. IL27RA encodes the IL-27 receptor alpha subunit5,6. In the absence of IL-27RA, phosphorylation of STAT1 and STAT3 by IL-27 is abolished in T cells. In in vitro studies, IL-27 exerts a synergistic effect on T-cell-receptor-dependent T cell proliferation7 that is deficient in cells from the patients, leading to impaired expansion of potent anti-EBV effector cytotoxic CD8+ T cells. IL-27 is produced by EBV-infected B lymphocytes and an IL-27RA-IL-27 autocrine loop is required for the maintenance of EBV-transformed B cells. This potentially explains the eventual favourable outcome of the EBV-induced viral disease in patients with IL-27RA deficiency. Furthermore, we identified neutralizing anti-IL-27 autoantibodies in most individuals who developed sporadic infectious mononucleosis and chronic EBV infection. These results demonstrate the critical role of IL-27RA-IL-27 in immunity to EBV, but also the hijacking of this defence by EBV to promote the expansion of infected transformed B cells.

NHP2 deficiency impairs rRNA biogenesis and causes pulmonary fibrosis and Høyeraal-Hreidarsson syndrome.

Telomeres are nucleoprotein structures at the end of chromosomes. The telomerase complex, constituted of the catalytic subunit TERT, the RNA matrix hTR and several cofactors, including the H/ACA box ribonucleoproteins Dyskerin, NOP10, GAR1, NAF1 and NHP2, regulates telomere length. In humans, inherited defects in telomere length maintenance are responsible for a wide spectrum of clinical premature aging manifestations including pulmonary fibrosis (PF), dyskeratosis congenita (DC), bone marrow failure and predisposition to cancer. NHP2 mutations have been so far reported only in two patients with DC. Here, we report the first case of Høyeraal-Hreidarsson syndrome, the severe form of DC, caused by biallelic missense mutations in NHP2. Additionally, we identified three unrelated patients with PF carrying NHP2 heterozygous mutations. Strikingly, one of these patients acquired a somatic mutation in the promoter of TERT that likely conferred a selective advantage in a subset of blood cells. Finally, we demonstrate that a functional deficit of human NHP2 affects ribosomal RNA biogenesis. Together, our results broaden the functional consequences and clinical spectrum of NHP2 deficiency.

Study of the potential role of CASPASE-10 mutations in the development of autoimmune lymphoproliferative syndrome.

Autoimmune lymphoproliferative syndrome (ALPS) is a primary disorder of lymphocyte homeostasis, leading to chronic lymphoproliferation, autoimmune cytopenia, and increased risk of lymphoma. The genetic landscape of ALPS includes mutations in FAS, FASLG, and FADD, all associated with apoptosis deficiency, while the role of CASP10 defect in the disease remains debated. In this study, we aimed to assess the impact of CASP10 variants on ALPS pathogenesis. We benefit from thousands of genetic analysis datasets performed in our Institute's genetic platform to identify individuals carrying CASP10 variants previously suspected to be involved in ALPS outcome: p.C401LfsX15, p.V410I and p.Y446C, both at heterozygous and homozygous state. Clinical and laboratory features of the six included subjects were variable but not consistent with ALPS. Two individuals were healthy. Comprehensive analyses of CASP10 protein expression and FAS-mediated apoptosis were conducted and compared to healthy controls and ALPS patients with FAS mutations. Missense CASP10 variants (p.V410I and p.Y446C), which are common in the general population, did not disrupt CASP10 expression, nor FAS-mediated apoptosis. In contrast, homozygous p.C401LfsX15 CASP10 variant lead to a complete abolished CASP10 expression but had no impact on FAS-mediated apoptosis function. At heterozygous state, this p.C401LfsX15 variant lead to a reduced CASP10 protein levels but remained associated with a normal FAS-mediated apoptosis function. These findings demonstrate that CASPASE 10 is dispensable for FAS-mediated apoptosis. In consequences, CASP10 defect unlikely contribute to ALPS pathogenesis, since they did not result in an impairment of FAS-mediated apoptosis nor in clinical features of ALPS in human. Moreover, the absence of FAS expression up-regulation in subjects with CASP10 variants rule out any compensatory mechanisms possibly involved in the normal apoptosis function observed. In conclusion, this study challenges the notion that CASP10 variants contribute to the development of ALPS.

Copy number variations and founder effect underlying complete IL-10Rß deficiency in Portuguese kindreds.

Mutations in interleukin-10 receptor (IL-10R) genes are one cause of very early-onset inflammatory bowel disease with perianal lesions, which can be cured by hematopoietic stem cell transplantation. Using a functional test, which assesses responsiveness of peripheral monocytes to IL-10, we identified three unrelated Portuguese patients carrying two novel IL-10RB mutations. In the three patients, sequencing of genomic DNA identified the same large deletion of exon 3 which precluded protein expression. This mutation was homozygous in two patients born from consanguineous families and heterozygous in the third patient born from unrelated parents. Microsatellite analysis of the IL10RB genomic region revealed a common haplotype in the three Portuguese families pointing to a founder deletion inherited from a common ancestor 400 years ago. In the third patient, surface expression of IL-10R was normal but signaling in response to IL-10 was impaired. Complementary DNA sequencing and next-generation sequencing of IL10RB locus with custom-made probes revealed a ≈ 6 Kb duplication encompassing the exon 6 which leads to a frameshift mutation and a loss of the TYK2-interacting Box 2 motif. Altogether, we describe two novel copy number variations in IL10RB, one with founder effect and one preserving cell surface expression but abolishing signaling.

The meaning attributed by tutors to experiences involving human rights in the academic environment / Significados atribuídos pelos docentes às vivências envolvendo direitos humanos no ambiente acadêmico

Abstract: Introduction: Human Rights are inherent to the human condition, considering all aspects of life: the right to life, to an education, to freedom, to religion, to security and to work. Given that, it is important to nurture a Human Rights culture in educational institutions, aiming at improving inter-personal dynamics and the educational environment. The tutors' development, in this aspect, becomes fundamental. Objective: To understand the meanings attributed by tutors to their experiences involving Human Rights situations in the academic environment as the first step to implement teacher development in this area. Methods: qualitative study involving tutors from a college located in northeastern Brazil, which employs the Problem-Based Learning methodology, between December of 2019 and September of 2020. The collection was performed through focal groups with intentional selection. The script for the discussion was based in the National Plan for Human Rights Education, The Human Rights Education Manual, The Universal Human Rights Declaration and articles related to the discussion topic. Bardin content analysis was used. The project was approved by the Ethics Committee under CAAE number 22696919.3.0000.5569. Results: The studied analytic categories were: gender and sexuality, communication and freedom of speech, social minorities and student self-esteem and stigmatization. During the process of reinterpreting the collected content, the following empirical subcategories were identified: ableism, fatphobia, psychophobia and interpersonal conflicts. The tutors revealed having experienced conflicts involving Human Rights, as follows: gender oppression; homophobia by students and teachers; lack of racial representativeness among the college student population; fatphobia in the academic environment; decrease in student's performance due to mental health issues. The participant tutors also expressed insecurity when it came to intervening and giving feedback in such situations, as well as some lack of knowledge about Human Rights. Conclusion: The tutors reported episodes that demonstrated Human Rights violation practices in the academic environment and showed to be insecure about intervening in such situations, especially when these situations led to conflict between the students.

Resumo: Introdução: Os direitos humanos (DH) são inerentes à condição humana, considerando todos os aspectos da vida: o direito à vida, à educação, à liberdade, à religião, à segurança e ao trabalho. Dessa forma, é importante incentivar a cultura dos DH nas instituições de ensino, na intenção de qualificar as dinâmicas interpessoais e o ambiente educacional. O desenvolvimento docente nesse aspecto torna-se fundamental. Objetivo: Este estudo teve como objetivo compreender os significados atribuídos pelos tutores às vivências envolvendo DH no ambiente acadêmico como primeiro passo para instituir o desenvolvimento docente nessa área. Método: Trata-se de um estudo qualitativo, realizado entre dezembro de 2019 e setembro de 2020, que envolveu tutores de uma faculdade do Nordeste do Brasil cuja metodologia de ensino é a Aprendizagem Baseada em Problemas. A coleta se deu por meio de grupos focais com seleção intencional. O roteiro para a discussão foi baseado no Plano Nacional de Educação em Direitos Humanos, no Caderno de Educação em Direitos Humanos, na Declaração de Direitos Humanos e em artigos referentes ao tema. Utilizou-se a análise de conteúdo de Bardin. O projeto recebeu parecer favorável do Comitê de Ética em Pesquisa: CAAE nº 22696919.3.0000.5569. Resultado: As categorias analíticas estudadas foram: gênero e sexualidade, comunicação e liberdade de expressão, minorias sociais e estigmatização e autoestima do estudante. Durante o processo de reinterpretação das falas, identificaram-se as seguintes subcategorias empíricas: capacitismo, gordofobia, saúde mental, psicofobia e conflitos interpessoais. Os docentes revelaram conflitos envolvendo DH, a exemplo das seguintes situações: opressão de gênero; homofobia por parte de docentes e estudantes; falta de representatividade racial na faculdade; gordofobia no ambiente acadêmico; queda de rendimento de estudantes por problemas de saúde mental. Expressaram insegurança em intervir e dar feedback em tais situações, bem como certo desconhecimento relacionado aos DH. Conclusão: Os docentes relataram episódios que demonstram práticas de violação aos DH no ambiente acadêmico e se mostraram inseguros para intervir nessas situações, sobretudo quando geravam conflito entre os estudantes.