Minipuberty and Sexual Dimorphism in the Infant Human Thymus

Area of Science:

• Immunology
• Developmental Biology
• Endocrinology

Background:

• Estrogen downregulates AIRE in the thymus post-puberty, potentially increasing autoimmune disease susceptibility in females.
• Minipuberty, a transient rise in sex hormones in early infancy, may impact thymic development and immune regulation.

Purpose of the Study:

• To investigate the effects of minipuberty on male and female infant thymic tissue.
• To determine if early sex hormone increases affect thymic transcriptional networks and AIRE expression.

Main Methods:

• Gene co-expression network analysis of differentially expressed genes.
• miRNA-target analysis.
• Genomic and immunohistochemical assays for AIRE expression.

Main Results:

• Sex differences in thymic tissue were observed during minipuberty but not in the non-puberty group (7-18 months).
• AIRE expression levels were similar between sexes in both minipuberty and non-puberty groups.
• AIRE-interactor networks exhibited sex-related gene expression correlation differences across all groups.

Conclusions:

• Minipuberty and genomic mechanisms interact to shape thymic sexual dimorphism within the first six months of life.
• Early hormonal fluctuations influence thymic gene regulatory networks, contributing to sex-specific immune development.