Original Paper

Immunomodulatory Effect of Vitamin C on Intracytoplasmic Cytokine Production in Neonatal Cord Blood Cells
Christoph Härtel, Alexander Puzik, Wolfgang Göpel, Petra Temming, Peter Bucsky, Christian Schultz

Department of Pediatrics, University of Lübeck Medical School, Lübeck, Germany

Address of Corresponding Author

Neonatology 2007;91:54-60 (DOI: 10.1159/000096972)

  Key Words

• Vitamin C
• Neonate
• Cord blood
• Pro-inflammatory cytokine

  Abstract

Background: Vitamin C (ascorbic acid) is an essential water-soluble antioxidant in cells and plasma. Besides metabolic functions, vitamin C is also known to contribute to immune homeostasis. Recently, it has been demonstrated that vitamin C has an inhibitory effect on the expression of pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor alpha (TNF-) in adult whole blood cells in vitro. It has been postulated that vitamin C might be an interesting compound for modulation of an over-exuberant immune response, e.g., in patient cohorts susceptible for the development of systemic inflammatory response syndrome such as neonates. It was the aim of this study to investigate the modulatory effects of vitamin C on the production of inflammatory mediators in neonatal cord blood cells. Methods: The intracytoplasmic production of pro-inflammatory cytokines in neonatal cord blood cells stimulated with lipopolysaccharide or phorbol 12-myristate 13-acetate/ionomycin was assessed by flow-cytometry. Results: In contrast to our previous observations from adult whole blood cells, 20 mM vitamin C mildly stimulated the percentage of neonatal monocytes producing IL-6 after lipopolysaccharide stimulation (e.g., 11.3% increase compared to control, p = 0.005). In the presence of 20 mM vitamin C, even a stronger stimulatory effect was noted for the percentage of IL-8 (e.g., 46.7% increase, p < 0.001) and TNF- producing neonatal monocytes (e.g., 69.2% increase, p = 0.004; n = 20). In accordance with adult data, the percentage of neonatal lymphocytes producing IL-2 after phorbol 12-myristate 13-acetate/ionomycin stimulation was dose-dependently reduced (e.g., 41.3% inhibition, p = 0.001, 20 mM vitamin C), while the percentage of TNF- producing lymphocytes was mildly stimulated (e.g., 20.8% increase, p = 0.003, 20 mM vitamin C). Conclusions: Interestingly, vitamin C was demonstrated to enhance pro-inflammatory responses in CD14⁺ cord blood cells while only intracellular IL-2 production in CD3⁺ cells was diminished. These data suggest that vitamin C differentially influences intracytoplasmic cytokine production in adults and neonates, and further studies are needed to elucidate the underlying mechanisms of this selective immunomodulation.

Copyright © 2007 S. Karger AG, Basel

  Author Contacts

Christoph Härtel, MD
Department of Pediatrics, University of Lübeck Medical School
Ratzeburger Allee 160, DE-23538 Lübeck (Germany)
Tel. +49 451 500 2567, Fax +49 451 500 3767
E-Mail haertel@paedia.ukl.mu-luebeck.de

  Article Information

Received: October 11, 2005
Accepted after revision: March 23, 2006
Published online: November 10, 2006
Number of Print Pages : 7
Number of Figures : 2, Number of Tables : 1, Number of References : 39