Neonates are at increased risk of infections compared to adults. To dissect the mechanisms that contribute to neonatal immune deficiency, we compared MHC-II antigen processing and presentation by monocytes from umbilical cord blood and unrelated adult controls. Antigen-specific, co-stimulation-independent murine T hybridoma cells were used to detect peptide:HLA-DR complexes. Relative to adult monocytes, neonatal monocytes were significantly defective in processing and presentation of protein antigens and presentation of exogenous peptide. Defects in responses to protein antigens and exogenous peptide were of similar magnitude (56-81% decrease), indicating that the defect lies in antigen presentation as opposed to intracellular antigen processing. Average surface MHC-II levels on neonatal monocytes were 38% less than on adult monocytes. However, there was no correlation between decreased MHC-II expression on individual neonatal monocyte samples and reduced T cell responses. We demonstrate for the first time that neonatal monocytes are defective in MHC-II antigen presentation by a mechanism not correlated with decreased MHC-II expression.
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http://dx.doi.org/10.1016/j.cellimm.2007.01.003 | DOI Listing |
Front Cardiovasc Med
December 2024
Seattle Children's Hospital, Seattle, WA, United States.
Introduction: The use of cardiopulmonary bypass (CPB) can induce sterile systemic inflammation that contributes to morbidity and mortality, especially in children. Patients have been found to have increased expression of cytokines and transmigration of leukocytes during and after CPB. Previous work has demonstrated that the supraphysiologic shear stresses existing during CPB are sufficient to induce proinflammatory behavior in non-adherent monocytes.
View Article and Find Full Text PDFBrain Behav Immun
December 2024
Department of Anesthesia, Division of Pain Management, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Pediatric Pain Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, OH, United States. Electronic address:
Neonatal pain is a significant clinical issue but the mechanisms by which pain is produced early in life are poorly understood. Our recent work has linked the transcription factor serum response factor downstream of local growth hormone (GH) signaling to incision-related hypersensitivity in neonates. However, it remains unclear if similar mechanisms contribute to inflammatory pain in neonates.
View Article and Find Full Text PDFDev Cell
November 2024
Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA; University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center, Baltimore, MD, USA; Medicine Institute for Neuroscience Discovery, University of Maryland, Baltimore, MD 21201, USA. Electronic address:
Brain development is a non-linear process of regionally specific epochs occurring during windows of sensitivity to endogenous and exogenous stimuli. We have identified an epoch in the neonatal rat brain defined by a transient population of peri-hippocampal mast cells (phMCs) that are abundant from birth through 2-weeks post-natal but absent thereafter. The phMCs are maintained by proliferation and harbor a unique transcriptome compared with mast cells residing in the skin, bone marrow, or other brain regions.
View Article and Find Full Text PDFArq Bras Cardiol
November 2024
Ankara Bilkent City Hospital - Division of Neonatology, Department of Pediatrics, Cankaya, Ankara - Turquia.
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