PROJECT SUMMARY: Neurodevelopmental impairment remains the most vexing issue facing the clinical
management of premature infants. Intrauterine infection and inflammation are significant causes of preterm
birth potentially resulting in lifelong neurodevelopmental impairment, such as cerebral palsy, sensory and
cognitive deficits and behavioral difficulties. Ureaplasma is a bacterial species that is a common cause of
preterm labor and non-human primates (NHP) are the most clinically relevant animal model in which to study
human preterm labor and fetal brain injury. Our unique chronically catheterized rhesus monkey model allows
constant physiological monitoring and longitudinal sampling of amniotic, maternal and fetal compartments and
evaluation of treatments longitudinally across gestation. In our previous NHP studies, antibiotic treatment
(Azithromycin) of intrauterine infection with Ureaplasma has been shown to delay preterm labor and improve
fetal lung and hemodynamic outcomes. Novel immunomodulatory drugs proposed for the treatment of preterm
labor would need to be combined with antimicrobials such as Azithromycin in the setting of intrauterine
infection. However, mechanisms of perinatal brain injury and the action of antibiotics on the fetal brain in
relation to intrauterine infection remain poorly understood. Therefore, the objective of this proposal is to
determine how Azithromycin treatment may modulate fetal neuroinflammation caused by intrauterine
Ureaplasma infection, to improve fetal neurodevelopmental outcomes. Data from our previous NHP studies of
intrauterine Ureaplasma infection added to this resubmission includes evidence of: i) placental membrane
inflammation and inflammasome activation; ii) maternal Azithromycin treatment normalization of fetal blood
flow; and iii) preliminary data that fetal brain microglial activation is fully reversed by azithromycin treatment.
We also provide NHP data for detection of fetal neural extracellular vesicle markers of perinatal brain injury. In
Aim 1 we will assess physiological aspects of preterm labor and immune responses to intrauterine infection
and antibiotic treatment. Aim 2 will determine fetal brain molecular, histological and spatial transcriptomic
changes with Ureaplasma infection and Azithromycin treatment. In addition, we will characterize the
expression of microglia/astrocyte activation phenotypes and myelin development associated with
neuroinflammation. Aim 3 will investigate how fetal brain extracellular vesicles extracted from maternal blood
may be used as a novel, non-invasive diagnostic tool for perinatal brain injury and for the monitoring of
Azithromycin efficacy and safety. Development of novel diagnostic technologies is essential for the in vivo
monitoring of fetal status in response to treatment. Using a combination of novel techniques and our clinically
relevant NHP model, this proposal utilizes our team's extensive experience in studying pregnancy physiology,
fetal neurodevelopment and immunology. Successful completion of this study will provide essential missing
translational data on the mechanisms of fetal neuroinflammation and perinatal brain injury and its treatment.