O papel modulador do gene AIRE - capes

Molecular Immunology 43 (2006) 464–472Hybridization signatures of gamma-irradiated murine fetal thymusorgan culture (FTOC) reveal modulation of genes associated withT-cell receptor V(D)J recombination and DNA repairRenato S. Cardoso a , Cristina M. Junta a , Claudia Macedo a , Danielle A.R. Magalhães a ,Eduardo L.V. Silveira a , Marina O. Paula a ,Márcia M.C. Marques a , Stephano S. Mello b ,Carlos R. Zárate-Bladés c , Catherine Nguyen d , Remi Houlgatte d , Eduardo A. Donadi e ,Elza T. Sakamoto-Hojo b , Geraldo A.S. Passos a,f,∗a Molecular Immunogenetics Group, Department of Genetics, Faculty of Medicine, University of São Paulo (USP), 14040-900 Ribeirão Preto, SP, Brazilb Laboratory of Cytogenetics and Mutagenesis, Department of Genetics, Faculty of Medicine, USP, 14040-900 Ribeirão Preto, SP, Brazilc Basic and Applied Immunology Program, Faculty of Medicine, USP, 14040-900 Ribeirão Preto, SP, Brazild Advanced Technologies for the Genome and Clinics (TAGC), INSERM Unit ERM 206, 13288 Marseille, Francee Department of Medicine, Faculty of Medicine, USP, 14040-900 Ribeirão Preto, SP, Brazilf Discipline of Genetics (DMEF), Faculty of Dentistry, USP, 14040-900 Ribeirão Preto, SP, BrazilReceived 28 October 2004; accepted 4 March 2005Available online 13 April 2005AbstractIn this study, we observed the occurrence of TRBV8.1-DB2.1 V(D)J recombination in murine fetal thymus organ culture (FTOC), inwhich the thymic microenvironment is mimicked. Since ionizing radiation affects T-cell development, we irradiated FTOCs with gamma raysto evaluate the modulation of genes implicated in TRBV8.1-BD2.1 rearrangements. The nylon cDNA microarray method was employed tomonitor the expression of 9216 genes, which were organized in coexpression clusters. Clustering analysis showed similar expression profiling ofgenes implicated in the V(D)J recombination and DNA double strand break (DSB) repair processes such as XRCC4, RAG-2, Artemis and DNA-PK-cs, thus suggesting overlap between the two processes. The RUNX3 gene, whose coded protein binds to the enhancers of TR genes, wasalso modulated and the DNA cross-linking LR1 gene, which plays a role in the opening of hairpin DNA structures and whose expression patternis similar to Artemis, may play a role in the control of V(D)J recombination. Furthermore, our data demonstrate that the FTOC model systemand cDNA microarray method are useful tools to evidentiate genes that may play a role in both processes V(D)J recombination and DNA repair.© 2005 Elsevier Ltd. All rights reserved.Keywords: FTOC; T-cell receptor beta; V(D)J recombination; DNA repair; cDNA microarray; Transcriptome profiling; Ionizing radiation1. IntroductionThe differentiation of thymocytes to mature T-cells occurswithin the fetal thymus and all developmental stagesare distinguishable by their expression of a combination ofCD cell-surface markers. This is a highly modulated phenomenonwhose central molecular machinery is formed bythe recombinase complex (recombination activating genes,∗ Corresponding author. Tel.: +55 16 602 30 30; fax: +55 16 633 00 69.E-mail address: passos@rge.fmrp.usp.br (G.A.S. Passos).RAG-1 and RAG-2) directly implicated in the V(D)J recombinationof T-cell receptor (TRA, TRB, TRG and TRD) andimmunoglobulin (Ig) gene segments (Lefranc and Lefranc,2001).The occurrence of the V(D)J reaction is important fortriggering the maturation of T-cells and is also regulated byseveral other gene products such as interleukins (Mueggeet al., 1993; Sollof et al., 1997; Fink and McMahan, 2000;Fugmann, 2002; Espanhol et al., 2003). Using the cDNAarray method, we have previously found that during a fetalphase of the in vivo development of the murine thymus, when0161-5890/$ – see front matter © 2005 Elsevier Ltd. All rights reserved.doi:10.1016/j.molimm.2005.03.010