RESUMEN
The high risk of neonatal death from sepsis is thought to result from impaired responses by innate immune cells; however, the clinical observation of hyperinflammatory courses of neonatal sepsis contradicts this concept. Using transcriptomic, epigenetic and immunological approaches, we demonstrated that high amounts of the perinatal alarmins S100A8 and S100A9 specifically altered MyD88-dependent proinflammatory gene programs. S100 programming prevented hyperinflammatory responses without impairing pathogen defense. TRIF-adaptor-dependent regulatory genes remained unaffected by perinatal S100 programming and responded strongly to lipopolysaccharide, but were barely expressed. Steady-state expression of TRIF-dependent genes increased only gradually during the first year of life in human neonates, shifting immune regulation toward the adult phenotype. Disruption of this critical sequence of transient alarmin programming and subsequent reprogramming of regulatory pathways increased the risk of hyperinflammation and sepsis. Collectively these data suggest that neonates are characterized by a selective, transient microbial unresponsiveness that prevents harmful hyperinflammation in the delicate neonate while allowing for sufficient immunological protection.
Asunto(s)
Calgranulina A/inmunología , Calgranulina B/inmunología , Inmunidad Innata/inmunología , Monocitos/inmunología , Sepsis Neonatal/inmunología , Proteínas Adaptadoras del Transporte Vesicular/genética , Proteínas Adaptadoras del Transporte Vesicular/inmunología , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Animales , Animales Recién Nacidos , Calgranulina A/efectos de los fármacos , Calgranulina B/efectos de los fármacos , Epigénesis Genética , Sangre Fetal , Citometría de Flujo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Humanos , Inmunidad Innata/efectos de los fármacos , Immunoblotting , Recién Nacido , Inflamación , Lipopolisacáridos/farmacología , Ratones , Ratones Noqueados , Monocitos/efectos de los fármacos , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/inmunología , Sepsis Neonatal/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptor Toll-Like 4/inmunologíaRESUMEN
AMPK (adenosine monophosphate-activated protein kinase) is phosphorylated (AMPK-P) in response to low energy through allosteric activation by Adenosine mono- or diphosphate (AMP/ADP). Folliculin (FLCN) and the FLCN-interacting proteins 1 and 2 (FNIP1, 2) modulate AMPK. FNIP1 deficiency patients have a AMPK-P gain of function phenotype with hypertrophic cardiomyopathy, Wolff-Parkinson-White pre-excitation syndrome, myopathy of skeletal muscles and combined immunodeficiency.
Asunto(s)
Cardiomiopatías , Proteínas Portadoras , Genes Recesivos , Síndromes de Inmunodeficiencia , Mutación , Síndromes de Preexcitación , Cardiomiopatías/genética , Cardiomiopatías/inmunología , Cardiomiopatías/patología , Proteínas Portadoras/genética , Proteínas Portadoras/inmunología , Femenino , Humanos , Síndromes de Inmunodeficiencia/genética , Síndromes de Inmunodeficiencia/inmunología , Síndromes de Inmunodeficiencia/patología , Masculino , Síndromes de Preexcitación/genética , Síndromes de Preexcitación/inmunología , Síndromes de Preexcitación/patologíaRESUMEN
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-α. In mice, pharmacological inhibition of TNF-α directly after birth prevented subsequent fatal SIRS but completely abrogated the recruitment of leukocytes to sites of infection. Importantly, in healthy neonates, blocking TNF-α at birth disrupted the physiologic leukocyte trafficking, which resulted in persistently altered leukocyte profiles at barrier sites. Collectively, these data suggest that constitutive TNF-α-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., Völlger, L., Willers, M., Richter, M., Böhne, C., Albrecht, M., Langer, M., Pfeifer, S., Jonigk, D., Vieten, G., Ure, B., von Kaisenberg, C., Förster, R., von Köckritz-Blickwede, M., Hansen, G., Viemann, D. Constitutive TNF-α signaling in neonates is essential for the development of tissue-resident leukocyte profiles at barrier sites.