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Updated: Aug 29, 2025
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Published on: August 12, 2020
Antimicrobial Peptides in Early-Life Host Defense, Perinatal Infections, and Necrotizing Enterocolitis-An Update
Eleni Agakidou1, Charalampos Agakidis2, Angeliki Kontou1
11st Department of Neonatology and Neonatal Intensive Care, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Ippokration General Hospital, 49 Konstantinoupoleos Str, 54642 Thessaloniki, Greece.
Insights
Antimicrobial peptides (AMPs) are crucial for infant immunity against infections. Research suggests AMPs could be vital for diagnosing, preventing, and treating early-life infections, offering alternatives to antibiotics.
Area of Science:
- Neonatal immunology
- Infectious diseases
- Biomarker discovery
Background:
- Innate immunity, particularly antimicrobial peptides (AMPs), is key for host defense against early-life infections like chorioamnionitis, neonatal sepsis, and necrotizing enterocolitis (NEC).
- Key AMPs include defensins, cathelicidin LL-37, elafin, SLPI, and hepcidin, produced by maternal and fetal tissues, and found in milk.
- These peptides exhibit antimicrobial, immunomodulatory, and tissue-repair functions, with expression increasing during gestation.
Purpose of the Study:
- To provide an overview of human AMPs' properties, sources, and expression changes during fetal and neonatal infections.
- To explore the potential utility of AMPs in managing early-life infections, including their role in diagnosis, prognosis, and therapy.
- To highlight AMPs as potential alternatives or adjuncts to antibiotics, addressing rising antibiotic resistance in neonatal intensive care units.
Main Methods:
- Literature review and synthesis of existing research on AMPs in early-life infections.
- Analysis of AMP expression patterns during gestation and in response to prenatal/postnatal infections and NEC.
- Discussion of emerging data on AMPs as diagnostic, predictive, and therapeutic agents.
Main Results:
- Evidence supports AMPs' involvement in the pathogenesis and severity of chorioamnionitis, neonatal sepsis, and NEC.
- AMPs are expressed early in development and increase throughout gestation.
- Limited studies exist on specific AMP levels in fetuses and neonates, but their role is increasingly recognized.
Conclusions:
- Antimicrobial peptides play a significant role in protecting newborns from infections.
- AMPs show promise as biomarkers for early detection and prognosis of neonatal infections.
- AMPs represent a potential therapeutic strategy to combat antibiotic-resistant infections in neonates.
Abstract:
Host defense against early-life infections such as chorioamnionitis, neonatal sepsis, or necrotizing enterocolitis (NEC) relies primarily on innate immunity, in which antimicrobial peptides (AMPs) play a major role. AMPs that are important for the fetus and neonate include α and β defensins, cathelicidin LL-37, antiproteases (elafin, SLPI), and hepcidin. They can be produced by the fetus or neonate, the placenta, chorioamniotic membranes, recruited neutrophils, and milk-protein ingestion or proteolysis. They possess antimicrobial, immunomodulating, inflammation-regulating, and tissue-repairing properties. AMPs are expressed as early as the 13th week and increase progressively through gestation. Limited studies are available on AMP expression and levels in the fetus and neonate. Nevertheless, existing evidence supports the role of AMPs in pathogenesis of chorioamnionitis, neonatal sepsis, and NEC, and their association with disease severity. This suggests a potential role of AMPs in diagnosis, prevention, prognosis, and treatment of sepsis and NEC. Herein, we present an overview of the antimicrobial and immunomodulating properties of human AMPs, their sources in the intrauterine environment, fetus, and neonate, and their changes during pre- and post-natal infections and NEC. We also discuss emerging data regarding the potential utility of AMPs in early-life infections, as diagnostic or predictive biomarkers and as therapeutic alternatives or adjuncts to antibiotic therapy considering the increase of antibiotic resistance in neonatal intensive care units.
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