TY - JOUR A1 - Twisselmann, Nele A1 - Pagel, Julia A1 - Künstner, Axel A1 - Weckmann, Markus A1 - Hartz, Annika A1 - Glaser, Kirsten A1 - Hilgendorff, Anne A1 - Göpel, Wolfgang A1 - Busch, Hauke A1 - Herting, Egbert A1 - Weinberg, Jason B. A1 - Härtel, Christoph T1 - Hyperoxia/Hypoxia Exposure Primes a Sustained Pro-Inflammatory Profile of Preterm Infant Macrophages Upon LPS Stimulation JF - Frontiers in Immunology N2 - Preterm infants are highly susceptible to sustained lung inflammation, which may be triggered by exposure to multiple environmental cues such as supplemental oxygen (O\(_2\)) and infections. We hypothesized that dysregulated macrophage (MФ) activation is a key feature leading to inflammation-mediated development of bronchopulmonary dysplasia (BPD) in preterm infants. Therefore, we aimed to determine age-dependent differences in immune responses of monocyte-derived MФ comparing cord blood samples derived from preterm (n=14) and term (n=19) infants as well as peripheral blood samples from healthy adults (n=17) after lipopolysaccharide (LPS) exposure. Compared to term and adult MФ, LPS-stimulated preterm MФ showed an enhanced and sustained pro-inflammatory immune response determined by transcriptome analysis, cytokine release inducing a RORC upregulation due to T cell polarization of neonatal T cells, and TLR4 surface expression. In addition, a double-hit model was developed to study pulmonary relevant exposure factors by priming MФ with hyperoxia (O\(_2\) = 65%) or hypoxia (O\(_2\) = 3%) followed by lipopolysaccharide (LPS, 100ng/ml). When primed by 65% O\(_2\), subsequent LPS stimulation in preterm MФ led to an exaggerated pro-inflammatory response (e.g. increased HLA-DR expression and cytokine release) compared to LPS stimulation alone. Both, exposure to 65% or 3% O\(_2\) together with subsequent LPS stimulation, resulted in an exaggerated pro-inflammatory response of preterm MФ determined by transcriptome analysis. Downregulation of two major transcriptional factors, early growth response gene (Egr)-2 and growth factor independence 1 (Gfi1), were identified to play a role in the exaggerated pro-inflammatory response of preterm MФ to LPS insult after priming with 65% or 3% O\(_2\). Preterm MФ responses to LPS and hyperoxia/hypoxia suggest their involvement in excessive inflammation due to age-dependent differences, potentially mediated by downregulation of Egr2 and Gfi1 in the developing lung. KW - preterm infants KW - sustained inflammation KW - macrophages KW - hyperoxia KW - hypoxia KW - infection KW - bronchopulmonary dysplasia Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-250356 SN - 1664-3224 VL - 12 ER - TY - JOUR A1 - Humberg, Alexander A1 - Fortmann, Ingmar A1 - Siller, Bastian A1 - Kopp, Matthias Volkmar A1 - Herting, Egbert A1 - Göpel, Wolfgang A1 - Härtel, Christoph T1 - Preterm birth and sustained inflammation: consequences for the neonate JF - Seminars in Immunopathology N2 - Almost half of all preterm births are caused or triggered by an inflammatory process at the feto-maternal interface resulting in preterm labor or rupture of membranes with or without chorioamnionitis (“first inflammatory hit”). Preterm babies have highly vulnerable body surfaces and immature organ systems. They are postnatally confronted with a drastically altered antigen exposure including hospital-specific microbes, artificial devices, drugs, nutritional antigens, and hypoxia or hyperoxia (“second inflammatory hit”). This is of particular importance to extremely preterm infants born before 28 weeks, as they have not experienced important “third-trimester” adaptation processes to tolerate maternal and self-antigens. Instead of a balanced adaptation to extrauterine life, the delicate co-regulation between immune defense mechanisms and immunosuppression (tolerance) to allow microbiome establishment is therefore often disturbed. Hence, preterm infants are predisposed to sepsis but also to several injurious conditions that can contribute to the onset or perpetuation of sustained inflammation (SI). This is a continuing challenge to clinicians involved in the care of preterm infants, as SI is regarded as a crucial mediator for mortality and the development of morbidities in preterm infants. This review will outline the (i) role of inflammation for short-term consequences of preterm birth and (ii) the effect of SI on organ development and long-term outcome. KW - preterm infants KW - sustained inflammation KW - sepsis KW - microbiome KW - neurocognitive outcome KW - chronic pulmonary insufficiency of prematurity Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235019 SN - 1863-2297 VL - 42 ER -