The absence of the autoimmune regulator gene (AIRE) impairs the three-dimensional structure of medullary thymic epithelial cell spheroids

Author(s)

Monteleone-Cassiano, Ana Carolina ; Dernowsek, Janaina A. ; Mascarenhas, Romario S. ; Assis, Amanda Freire ; Pitol, Dimitrius ; Santos Moreira, Natalia Chermont ; Sakamoto-Hojo, Elza Tiemi ; Mardegan Issa, Joao Paulo ; Donadi, Eduardo A. ; Passos, Geraldo Aleixo

• Document type: Journal article
• Source: BMC MOLECULAR AND CELL BIOLOGY; v. 23, n. 1, p. 17-pg., 2022-03-24.

Abstract

Background Besides controlling the expression of peripheral tissue antigens, the autoimmune regulator (AIRE) gene also regulates the expression of adhesion genes in medullary thymic epithelial cells (mTECs), an essential process for mTEC-thymocyte interaction for triggering the negative selection in the thymus. For these processes to occur, it is necessary that the medulla compartment forms an adequate three-dimensional (3D) architecture, preserving the thymic medulla. Previous studies have shown that AIRE knockout (KO) mice have a small and disorganized thymic medulla; however, whether AIRE influences the mTEC-mTEC interaction in the maintenance of the 3D structure has been little explored. Considering that AIRE controls cell adhesion genes, we hypothesized that this gene affects 3D mTEC-mTEC interaction. To test this, we constructed an in vitro model system for mTEC spheroid formation, in which cells adhere to each other, establishing a 3D structure. Results The comparisons between AIRE wild type (AIRE(WT)) and AIRE KO (AIRE(-/-)) 3D mTEC spheroid formation showed that the absence of AIRE: i) disorganizes the 3D structure of mTEC spheroids, ii) increases the proportion of cells at the G0/G1 phase of the cell cycle, iii) increases the rate of mTEC apoptosis, iv) decreases the strength of mTEC-mTEC adhesion, v) promotes a differential regulation of mTEC classical surface markers, and vi) modulates genes encoding adhesion and other molecules. Conclusions Overall, the results show that AIRE influences the 3D structuring of mTECs when these cells begin the spheroid formation through controlling cell adhesion genes. (AU)

• FAPESP's process: 19/23448-3 - Effect of Aire gene mutations (APS1 Syndrome) induced by CRISPR-Cas9 in protein conformation, transcriptome of mTEC cells and its interaction with thymocytes
• Grantee: Ana Carolina Monteleone Cassiano
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 17/10780-4 - Effect of CRISPR-Cas9-induced mutations in the Aire gene (APS1 syndrome) on protein conformation, mTEC cell transcriptome and their interaction with thymocytes
• Grantee: Geraldo Aleixo da Silva Passos Júnior
• Support Opportunities: Research Projects - Thematic Grants