Altered innate immunity and monocyte functional impairment characterize healthy preterm newborns

Abstract

Abstract Preterm birth (PT) is defined as birth before 37 completed weeks of gestation, and it is one of the most frequent pregnancy complications and infections. Understanding susceptibility to infectious disease in preterm infants by identifying alterations in innate immune profile could pave the way to novel clinical intervention. Neonatal immunity is a developing structure that evolves gradually. Monocytes are the key players after birth and may change susceptibility to additional infectious or inflammatory. One of the main functions of monocytes is to activate the inflammasomes, whose levels are high in preterm newborns. Here, by using high-dimensional flow cytometry, gene expression and quantification of plasma cytokine levels in a total of 68 term and preterm newborns, we report that preterm newborns show higher plasmatic concentration of alarmin S100A8, higher proportion of CD56+/−CD16+NK cells, higher proportion of immature monocytes and a lower proportion of classical monocytes and lower inflammasome activation after in vitro monocyte stimulation. Our findings suggest that altered innate immunity and monocyte functional impairment characterize healthy preterm newborns, which display different proportions of innate immune cells and diverse pro-inflammatory plasmatic profile.