Interleukin 2 receptor regulation and IL-2 function in the human infant
Date
1998
Authors
Zola, H.
Ridings, J.
Elliott, S.
Nobbs, S.
Weedon, H.
Wheatland, L.
Haslam, R.
Roberton, D.
Macardle, P.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Human Immunology, 1998; 59(10):615-624
Statement of Responsibility
Conference Name
Abstract
IL-2 receptor is expressed at low levels on adult blood lymphocytes, and at lower levels on cord blood cells. IL-2 receptor alpha and beta chain expression increases gradually from 0-18 months of age. The level of soluble CD25 (IL-2 receptor alpha chain) has been reported to be elevated in cord blood. Quantitative RT-PCR showed that adult cells express 10 times as much CD25 mRNA as cord cells. Cord plasma showed only a marginal ability to strip CD25 from the membrane. To assess the functional consequences of low IL-2 receptor expression, cord and adult cells were activated in vitro. The response was stimulus-dependent, but cord cells upregulated CD25 readily. Cord and adult cells proliferated in an IL-2-dependent assay to a similar extent. Infants suffering acute infection showed marginally higher levels of membrane CD25 expression than infants without overt infection. Thus neonatal and infant lymphocytes express lower levels of IL-2 receptors than adult cells, reflecting lower mRNA concentrations at least for CD25; they are able to up-regulate receptors in response to in vitro stimulation and are able to respond in vitro to IL-2-dependent stimulation; however in vivo there may be a dampening down of the IL-2 system in infancy.