Transcriptional profiling of lung macrophages identifies a predictive signature for inflammatory lung disease in
Debashis Sahoo1,2,3, Livia S Zaramela1,4, Gilberto E Hernandez1
1Department of Pediatrics, Rady Children's Hospital, University of California, San Diego, La Jolla, CA, 92093, USA.
Insights
Newborn lung macrophage immaturity may contribute to bronchopulmonary dysplasia (BPD) in preterm infants. Gene expression analysis reveals distinct patterns in infants who develop BPD versus those resilient to it.
Area of Science:
- Neonatal immunology
- Developmental immunology
- Respiratory medicine
Background:
- Lung macrophages mature postnatally, creating a vulnerability window for newborns, especially preterm infants.
- Bronchopulmonary dysplasia (BPD) is a major complication of prematurity, potentially linked to immature lung immune cells.
Purpose of the Study:
- To investigate the role of lung macrophage immaturity in the development of BPD in preterm infants.
- To identify gene expression patterns in lung macrophages associated with BPD development or resilience.
Main Methods:
- Analysis of lung macrophage gene expression in preterm infants at risk for BPD.
- Comparison of gene expression profiles between infants who developed BPD and those who did not.
- Assessment of ex vivo response to lipopolysaccharide (LPS).
Main Results:
- Infants who developed BPD exhibited higher inflammatory mediator expression from the first day of life.
- Macrophage signature genes showed increased expression in the first week of life in disease-resilient infants.
- Ex vivo LPS response was uniform across all studied samples, suggesting intrinsic differences rather than extrinsic reactivity.
Conclusions:
- Lung macrophage immaturity is a potential contributor to BPD pathogenesis in preterm neonates.
- Specific gene expression dynamics during the first week of life reflect human lung macrophage differentiation.
- The study offers novel mechanistic insights into neonatal lung disease and developmental immunology.
Abstract:
Lung macrophages mature after birth, placing newborn infants, particularly those born preterm, within a unique window of susceptibility to disease. We hypothesized that in preterm infants, lung macrophage immaturity contributes to the development of bronchopulmonary dysplasia (BPD), the most common serious complication of prematurity. By measuring changes in lung macrophage gene expression in preterm patients at risk of BPD, we show here that patients eventually developing BPD had higher inflammatory mediator expression even on the first day of life. Surprisingly, the ex vivo response to LPS was similar across all samples. Our analysis did however uncover macrophage signature genes whose expression increased in the first week of life specifically in patients resilient to disease. We propose that these changes describe the dynamics of human lung macrophage differentiation. Our study therefore provides new mechanistic insight into both neonatal lung disease and human developmental immunology.
