title: Neonatal testosterone imprinting affects thymus development and leads to phenotypic rejuvenation and masculinization of the peripheral blood T-cell compartment in adult female rats.
abstract: Exposure of female rodents to testosterone in the critical neonatal period produces defeminization/masculinization of the hypothalamo-pituitary-gonadal (HPG) axis, i.e. neonatal androgenization and postpones axis maturation. To address the hypothesis that HPG axis signaling is involved in the programming of thymic maturation/involution and sexual differentiation we studied the impact of neonatal androgenization on thymic cellularity, development of effector and regulatory T cells, and phenotypic characteristics of peripheral blood T lymphocytes in adult rats. A single injection of testosterone on postnatal day 2 postponed thymic maturation/involution as revealed by organ hypercellularity, increased cellularity of the most mature (CD4+CD8- and CD4-CD8+) TCRalphabeta(high) thymocyte and both recent thymic emigrant (RTE) subsets and caused phenotypic defeminization/masculinization of thymic (decreased CD4+CD8-TCRalphabeta(high)/CD4-CD8+TCRalphabeta(high) cell ratio) and peripheral blood T-cell compartments (decreased CD4+RTE/CD8+RTE and CD4+/CD8+ cell ratio). In addition, neonatal androgenization increased the relative and absolute numbers of both CD4+CD25+Foxp3+ and natural killer (NK) regulatory T cells in peripheral blood. These findings, in conjunction with thymocyte overexpression of Thy-1 that is assumed to reduce negative selection affecting self-reactive cell generation, suggest a new relationship between self-reactive and regulatory T cells. In conclusion, our study provides additional evidence for a role of HPG signals (i.e. sex steroids and gonadotropins) in programming the kinetics of thymic maturation/involution and in establishing immunological sexual dimorphism.
authors.affiliation: Immunology Research Centre Branislav Janković, Institute of Virology, Vaccines and Sera Torlak, 458 Vojvode Stepe, 11221 Belgrade, Serbia. Gordana.Leposavic@pharmacy.bg.ac.rs
authors.forename: Gordana
authors.initials: G
authors.lastname: Leposavić
authors.forename: Milica
authors.initials: M
authors.lastname: Perisić
authors.forename: Dusko
authors.initials: D
authors.lastname: Kosec
authors.forename: Nevena
authors.initials: N
authors.lastname: Arsenović-Ranin
authors.forename: Katarina
authors.initials: K
authors.lastname: Radojević
authors.forename: Zorica
authors.initials: Z
authors.lastname: Stojić-Vukanić
authors.forename: Ivan
authors.initials: I
authors.lastname: Pilipović
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015704:CD4 Antigens / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D051858:Forkhead Transcription Factors / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D055611:Natural Killer T-Cells / Q000276:immunology; D015213:Neuroimmunomodulation / Q000276:immunology / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D013739:Testosterone / Q000008:administration & dosage / Q000494:pharmacology*; D018800:Thy-1 Antigens / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000254:growth & development / Q000276:immunology*
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D051858:Forkhead Transcription Factors; C500522:Foxp3 protein, rat; D053645:Interleukin-2 Receptor alpha Subunit; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018800:Thy-1 Antigens; D013739:Testosterone