Concentration-dependent effects of 17β-estradiol and progesterone reveal differential regulation of interferon-stimulated genes in bovine neutrophils.

Sex hormones influence the capacity of neutrophils to respond to challenges.The current in vitro study was undertaken to explore the concentration-dependent actions of estrogen and progesterone on heifer neutrophil gene expression patterns especially the selective interferon-stimulated genes (ISGs). The neutrophils were isolated from the blood of Sahiwal cattleheifers and were cultured subjecting them to different estrogen and progesterone concentrations (1000 pg/mL, 500 pg/mL, 100 pg/mL, 50 pg/mL and 10 pg/mL). The gene expression patterns of selective ISGs like Interferon Stimulated Gene 15 (ISG15), 2'5' oligoadenylatesynthetase (OAS1), Myxovirus Resistance 1 (MX1), Myxovirus Resistance 2 (MX2) and Gamma Interferon Inducible Protein 16 and 44 (IFI16, IFI44) were analyzed by quantitative real-time PCR. All genes studied except OAS1 and IFI16 exhibited altered expression patterns with varying hormonal concentrations. ISG15, MX1 and MX2 showed significant down-regulation at specific concentrations with both hormone treatments (P ≤ 0.05 to P ≤ 0.001), while IFI44 expression significantly decreased only with estrogen treatment (P ≤ 0.001). OAS1 and IFI16 remained unchanged with either hormone treatment. These findings demonstrate non-uniform responses among different ISGs and concentration-dependent variance in gene expression patterns, indicative of heterogeneity in neutrophil response to female sex hormones.