Newborn infants have a high disposition to develop systemic inflammatory response syndromes (SIRSs) upon inflammatory or infectious challenges. Moreover, there is a considerable trafficking of hematopoietic cells to tissues already under noninflammatory conditions. These age-specific characteristics suggest a hitherto unappreciated crucial role of the vascular endothelium during the neonatal period. Here, we demonstrate that healthy neonates showed already strong endothelial baseline activation, which was mediated by a constitutively increased production of TNF-alpha. In mice, pharmacological inhibition of TNF-alpha directly after birth prevented subsequent fatal SIRS but completely abrogated the recruitment of leukocytes to sites of infection. Importantly, in healthy neonates, blocking TNF-alpha at birth disrupted the physiologic leukocyte trafficking, which resulted in persistently altered leukocyte profiles at barrier sites. Collectively, these data suggest that constitutive TNF-alpha-mediated sterile endothelial activation in newborn infants contributes to the increased risk of developing SIRS but is needed to ensure the postnatal recruitment of leukocytes to organs and interfaces.-Bickes, M. S., Pirr, S., Heinemann, A. S., Fehlhaber, B., Halle, S., Vollger, L., Willers, M., Richter, M., Bohne, C., Albrecht, M., Langer, M., Pfeifer, S., Jonigk, D., Vieten, G., Ure, B., von Kaisenberg, C., Forster, R., von Kockritz-Blickwede, M., Hansen, G., Viemann, D. Constitutive TNF-alpha signaling in neonates is essential for the development of tissue-resident leukocyte profiles at barrier sites.
- Bickes, M. S.
- Pirr, S.
- Heinemann, A. S.
- Fehlhaber, B.
- Halle, S.
- Vollger, L.
- Willers, M.
- Richter, M.
- Bohne, C.
- Albrecht, M.
- Langer, M.
- Pfeifer, S.
- Jonigk, D.
- Vieten, G.
- Ure, B.
- von Kaisenberg, C.
- Forster, R.
- von Kockritz-Blickwede, M.
- Hansen, G.
- Viemann, D.
