Switching on the Aire conditioner

Aire has been cloned as the gene responsible for a hereditary type of organ‐specific autoimmune disease. Aire controls the expression of a wide array of tissue‐restricted Ags by medullary thymic epithelial cells (mTECs), thereby leading to clonal deletion and Treg‐cell production, and ultimately to the establishment of self‐tolerance. However, relatively little is known about the mechanism responsible for the control of Aire expression itself. In this issue of the European Journal of Immunology, Haljasorg et al. [Eur. J. Immunol. 2015. 45: 3246–3256] have reported the presence of an enhancer element for Aire that binds with NF‐κB components downstream of the TNF receptor family member, RANK (receptor activator of NF‐κB). The results suggest that RANK has a dual mode of action in Aire expression: one involving the promotion of mTEC differentiation and the other involving activation of the molecular switch for Aire within mature mTECs.     

Spatial (Tbata) expression in mature medullary thymic epithelial cells

The Spatial gene is expressed in highly polarized cell types such as testis germ cells, brain neurons and thymic epithelial cells (TEC). Its expression was documented in testis and brain but poorly characterized in thymus. Here, we characterize for the first time Spatial‐expressing TEC throughout ontogeny and adult mouse thymus. Spatial is expressed in thymic‐fated domain by embryonic day E10.5 and persists in subcapsular, cortical, medullary epithelial cells and in MTS24⁺ progenitor TEC. Using mouse strains in which thymocyte development is blocked at various stages, we show that Spatial expression is independent of thymocyte‐derived signals during thymus organogenesis. Analyses on purified thymic cell subsets show that Spatial short isoforms are expressed in cortical TEC (cTEC) and mature medullary TEC (mTEC). Spatial long isoforms were detected in the same TEC population. Spatial presents a nuclear distribution specific to mature mTEC expressing UEA1 and Aire. Aire‐ and RANKL‐deficient mice revealed that Spatial expression is drastically reduced in the thymus of these mutants. These findings reveal a critical function of Aire in regulating Spatial expression, which is compatible with promiscuous Spatial gene expression.     

A comparative study of mRNA and protein expression of the autoimmune regulator gene (Aire) in embryonic and adult murine tissues

Autoimmune polyendocrine syndrome type 1 (APS1) is a rare autosomal recessive human disorder caused by mutations in the autoimmune regulator gene (AIRE) and characterized by multiple autoimmune diseases. As reports of the tissue expression pattern of the murine Aire gene are discordant, a comprehensive survey of Aire expression was undertaken in adult and embryonic tissues at the mRNA and protein levels using real-time RT-PCR, in situ hybridization, and immunohistochemistry. In the adult, the highest Aire mRNA expression was in the thymus. All the other tissues investigated expressed Aire mRNA at low levels, but it was barely detectable in the adrenal gland. Aire protein expression was observed in the thymus, spleen, and lymph nodes. A common pattern was observed in other tissues, with staining in epithelial cells. An exception to this was the gut, where staining was seen in the mucin spaces. In embryonic tissue, Aire mRNA and protein expression was detected from E14.5 in the thymus. In the fetal liver, unlike the adult, staining was observed at E14.5 and decreased towards term. Thus, Aire is expressed in immunologically relevant tissues and in a restricted number of extra-immunological tissues in the adult. Furthermore, the presence of Aire protein is reported in extra-thymic tissues of the embryo.     

RÊVER cela n'est rien, mais DORMIR… Enjeux métapsychologiques, psychopathologiques et traumatologiques de l'endormissement

If the analytical literature abounds in references to the dream, since Freud, we note its poverty concerning the phase of drowsiness. However, following the dream example, halfway between the normal one and the pathological falling asleep raises many questions: loneliness or otherness? Pleasure or enjoyment? Internal, external or spaces between? All these questions will be raised in the context of trauma, sleep walking, psychosis on the coma. Thus we reject the idea of sleeping as being somehow obvious: our idea is not sleep is a return to primary repression. For that reason we try to give it the status of a practical nodel.     

IL‐22 neutralizing autoantibodies impair fungal clearance in murine oropharyngeal candidiasis model

Protection against mucocutaneous candidiasis depends on the T helper (Th)17 pathway, as gene defects affecting its integrity result in inability to clear Candida albicans infection on body surfaces. Moreover, autoantibodies neutralizing Th17 cytokines have been related to chronic candidiasis in a rare inherited disorder called autoimmune polyendocriopathy candidiasis ectodermal dystrophy (APECED) caused by mutations in autoimmune regulator (AIRE) gene. However, the direct pathogenicity of these autoantibodies has not yet been addressed. Here we show that the level of anti‐IL17A autoantibodies that develop in aged Aire‐deficient mice is not sufficient for conferring susceptibility to oropharyngeal candidiasis. However, patient‐derived monoclonal antibodies that cross‐react with murine IL‐22 increase the fungal burden on C. albicans infected mucosa. Nevertheless, the lack of macroscopically evident infectious pathology on the oral mucosa of infected mice suggests that additional susceptibility factors are needed to precipitate a clinical disease.     

小鼠Aire逆转录病毒表达载体的构建及表达

目的：将小鼠Aire基因定向连入MigR1-GFP质粒,得到长期稳定的Aire逆转录病毒表达载体,收集逆转录病毒上清感染胸腺基质细胞,为研究Aire在胸腺细胞终末分化中的作用奠定基础。方法：以小鼠胸腺基质细胞的cDNA为模板扩增得到Aire的ORF片段;将该片段连接入MigR1-GFP质粒;将构建成功的Aire—MigR1-GFP质粒转染293T细胞,收集逆转录病毒上清;使用逆转录病毒上清感染胸腺基质细胞系MTEC9,流式细胞仪检测感染效率,Western blot确定Aire蛋白的表达。结果：（1）成功得到Aire的ORF片段。（2）构建的Aire逆转录病毒表达质粒能够成功表达Aire蛋白。（3）逆转录病毒上清成功感染胸腺基质细胞系MTEC9。结论：成功构建了小鼠Aire逆转录病毒表达载体,并实现了Aire蛋白在胸腺基质细胞系中的强制性表达。