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Updated: Jul 9, 2026
Mapping Infant Immunity with Minimal Input: Integrative Single-Cell and Multiomic Profiling
Published on: April 3, 2026
Cytokine expression in response to bacterial antigens in preterm and term infant cord blood monocytes
A M Francesca Tatad1, Mirjana Nesin, John Peoples
1Department of Pediatrics, Host Defenses Program, Weill Cornell Medical College, Manhasset, NY 10021, USA.
Insights
Neonates show distinct immune responses to bacteria. Preterm infants have higher inflammatory responses to E. coli, while both preterm and term infants have lower IL-6 responses to S. epidermidis, increasing infection vulnerability.
Area of Science:
- Immunology
- Neonatal Research
- Bacterial Pathogenesis
Background:
- Neonatal immune systems are immature, increasing susceptibility to bacterial infections.
- Specific bacterial antigen roles in neonatal immune responses remain largely unknown.
Purpose of the Study:
- To compare intracellular cytokine responses to bacterial antigens in term and preterm infants versus adults.
- To investigate differences in immune mediator production by leukocytes.
Main Methods:
- Ex vivo culture of cord blood (neonates) and adult peripheral blood with heat-killed bacteria.
- Flow cytometry assessment of intracellular interleukin (IL)-6, IL-10, IL-12, and IL-8 production by leukocytes.
Main Results:
- Monocytes were the primary cytokine producers, with Escherichia coli being the most potent stimulant.
- Neonates exhibited lower IL-6 responses to Staphylococcus epidermidis compared to adults.
- Term neonates showed lower IL-8 responses to S. epidermidis than preterm infants and adults.
Conclusions:
- Term neonates display a downregulated anti-inflammatory response to specific bacteria compared to preterm neonates.
- Preterm infants' high response to pathogenic E. coli may lead to uncontrolled inflammation.
- Reduced neonatal IL-6 response to S. epidermidis suggests a basis for vulnerability to this infection.
Background:
Neonatal susceptibility to bacterial infection is associated with an immature immune system, but the role of different bacterial antigens in specific responses is largely unknown.
Objective:
To evaluate differences in intracellular cytokine response to physiologically relevant bacterial antigens in term and preterm infants as compared with adults.
Methods:
Cord blood samples from preterm and term neonates and adult peripheral blood samples were cultured ex vivo with and without whole heat-killed bacteria. Intracellular leukocyte production of interleukin (IL)-6, IL-10, IL-12, and IL-8 responses was assessed by flow cytometry.
Results:
Monocytes were the primary producers of all mediators. Escherichia coli was the most potent stimulant. Lactobacillus plantarum 299v activated fewer monocytes as compared with E. coli for all responses (p < 0.05), except for IL-12 in term neonates. IL-6 response to Staphylococcus epidermidis was lower in both groups of neonates as compared with adults (p = 0.023 and p = 0.001). IL-8 response to S. epidermidis was lower in term as compared with preterm neonates and adults (p = 0.003). IL-10 response to group B streptococci was lower in term neonates as compared with adults and higher in preterm as compared with term neonates (p = 0.015).
Conclusions:
Monocytes from term neonates compared to preterm neonates show a downregulated anti-inflammatory response to specific bacteria. High neonatal response to pathogenic E. coli in the preterm infant could cause uncontrolled inflammatory response, while lower IL-6 response to S. epidermidis in neonates may indicate a basis for vulnerability to S. epidermidis infection.
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