Thymic changes after chorioamnionitis induced by intraamniotic lipopolysaccharide in fetal sheep

Steffen Kunzmann, Kerstin Glogger, Jasper V. Been, Suhas G. Kallapur, Ilias Nitsos, Timothy J. M. Moss, Christian P. Speer, John P. Newnham, Alan H. Jobe, Boris W. Kramer*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


OBJECTIVE: Regulatory T lymphocytes mediate homeostasis of the immune system and differentiate under the control of the transcription factor FoxP3 in the fetal thymus. We asked whether fetal inflammation caused by chorioamnionitis would modulate thymus development. STUDY DESIGN: Fetal sheep were exposed to an intraamniotic injection of 10 mg lipopolysaccharide at 5 hours, 1 day, 2 days, or 5 days before delivery at 123 gestation days. Cord blood lymphocytes, plasma cortisol, and thymus weight were measured. Glucocorticoid receptor-, activated caspase-3-, Ki-67-, proliferating cell nuclear antigen-, nuclear factor-kappa B-, and FoxP3-positive cells were immunohistochemically evaluated in thymus. RESULTS: Intraamniotic lipopolysaccharide exposure decreased the number of circulating lymphocytes by 40% after 1 day. Thymus-to-body weight ratios were reduced in all lipopolysaccharide groups by a maximum of 40% at 5 days. Lipopolysaccharide exposure modestly increased plasma cortisol concentration, increased nuclear factor-kappa B immunostaining in fetal thymus and reduced the number of FoxP3-positive cells by 40% at 1 day. CONCLUSION: Intraamniotic exposure to lipopolysaccharide induced thymic changes and influenced thymic FoxP3 expression.
Original languageEnglish
Pages (from-to)476.e1-476.e9
JournalAmerican Journal of Obstetrics and Gynecology
Issue number5
Publication statusPublished - May 2010


  • Fetal inflammatory response syndrome
  • FoxP3
  • immune response
  • preterm
  • T lymphocyte
  • T-reg

Cite this