Poster #064
Role of Sex Chromosomes and Gonadal Hormones in Macrophage Sex Dimorphism
Mentors: Ramizah Syahirah, PhD and Helen Goodridge, PhD
Macrophages are immune cells that play a crucial role in host defense by releasing cytokines like TNF-α and IFN-β upon pathogen recognition. We studied macrophage responses to lipopolysaccharide (LPS), a Gram-negative bacterial cell wall component. Our data showed that male macrophages produce higher levels of TNF-α and IFN-β proteins upon LPS stimulation. We also observed similar Toll-like receptor (TLR4) and interferon alpha/beta receptor (IFNAR) protein expression on the surface of male and female macrophages. TLR4 is the receptor for LPS and IFNAR detects IFN-β to amplify the response to LPS. Since the expression of these receptors is similar in males and females, our data indicate that the observed sex differences in cytokine production arise due to the differences in the activity of downstream signaling proteins inside the cells. Future work will explore how X/Y chromosomes and gonadal hormones effect the signaling pathways to explain the sex dimorphism in macrophages.