Gene Expression of Defensin is Greatly Upregulated in Neonatal Neutrophils Following Labor (118.11)

Abstract

Abstract This investigation documents the variability of gene expression between neonatal and adult neutrophils at rest and following stimulation with lipopolysaccharide. Our hypothesis is that distinct gene expression differences will be observed between neonatal and adult neutrophils at rest and following stimulation with LPS. Methods: Cord (9) and adult (12) blood samples were collected per routine procedures. Neutrophils were isolated and divided into 3 groups, which were seeded at 1 X 10 6 ml into multiwall plates and incubated with or without LPS 10 ng/µL (Invivogen) for 0, 45, and 90 minutes. RNA was isolated and gene expression differences determined via the Illumina platform at the Oklahoma Medical Research Foundation. Signal intensities from each probe were quantitated, adjusted for local background, and quantile normalized (Matlabs; Natwick, MA) to adjust the marginal distribution of each sample. Summary: Neonatal cord neutrophils were up-regulated in > 75% of differentially expressed genes at each time point as compared to adults. This difference remained relatively unchanged prior to and following LPS stimulation. Furthermore, neonatal neutrophils demonstrated a 13-16 fold increase in the expression of defensins prior to and following LPS stimulation. Conclusion: Hierarchical clustering of gene expression results showed distinct differences between adult and cord neutrophils in unstimulated and stimulated states.