Our laboratory has shown that gene expression of multiple microbicidal RNAs is greatly up regulated in neonatal versus adult neutrophils, and that neonates have a higher percentage of circulating immature neutrophils than adults. The aims of this study were to determine if there was a difference in number of immature neutrophils or in the production of microbicidal proteins based on exposure to labor. Design: The ratio of immature to total neutrophils was determined via flow cytometry and complete blood counts. The maturational stage of the neutrophil was verified by neutrophil granule RNA production via Luminex QuantiGene Plex Assays and protein levels via ELISA. Results: Exposure to labor did not affect the number of circulating immature neutrophils in neonates (p=0.864), but those delivered without labor had more neutrophils at the earliest stages of development. There was no difference in α-defensin protein levels between samples, but lactoferrin was elevated in adult as compared to neonates without labor (p=0.0003), but not to those exposed to labor (p=0.087). Conclusion: Labor does not affect the number of immature neutrophils in neonates, but may “push” them to mature. While the gene expression of microbicidal proteins is greatly up regulated in neonatal neutrophils, the amount of protein produced is similar to or lower than adults. Studies are ongoing to determine if protein levels can be increased after stimulation by bacteria or other activators.
- Copyright © 2013 by The American Association of Immunologists, Inc.