Regulatory T-cells (Treg) have a protective role for the control of immune activation and tissue damage. The effects of chorioamnionitis (chorio) on Treg in moderate/late preterm newborns are not known. We hypothesized that infants exposed to chorio would have decreased Treg frequency and/or function.We isolated mononuclear cells from adult peripheral blood and cord blood from term and moderate/late preterm infants who were classified for severity of chorio exposure. Mononuclear cells were analyzed by flow cytometry for Treg frequency and phenotype. Treg suppression of activation of conventional T-cells (Tcon) was also quantified.Treg frequencies were similar in all groups of neonates, but lower than that found in adults. Newborn Treg had a naïve phenotype, with decreased levels of CD45RO, HLA-DR, CD39 and TIGIT compared to adult Treg and chorio did not affect the phenotype. Treg from preterm newborns exposed to severe chorio had higher expression of Ki67 compared to the other groups. Treg from preterm newborns were less suppressive than Treg from adults or term, and the level of suppression was reduced with severe chorio.Relative to term, Treg frequency and phenotype were not affected by prematurity and chorio but their functionality was decreased. Lower Treg activity may contribute to inflammation in newborns that is often associated with chorioamnionitis.
Bibliographical noteFunding Information:
The authors acknowledge the support provided by the Center for Excellence in Molecular Hematology Grant 1P30DK090971-01 and the Digestive Health Center Grant AR47363 , which partially supported the use of the Flow Cytometry and Luminex Cores. We would like to thank Manuel Alvarez Jr. for help with CB collection and processing, the Hatton Research Center at Good Samaritan Hospital, Rita Doerger RN, Peggy Walsh RN, Donna Lambers MD, Laurie Bambrick RN, and the Labor and Delivery obstetricians and nurses at Good Samaritan for their help with recruitment of study subjects, Karen Henderson, Thomas Panke MD for help with placenta processing.
© 2014 American Society for Histocompatibility and Immunogenetics.
- Fetal inflammation
- Full term newborn
- Regulatory T cell