title: Analysis of cytokine gene expression during fetal thymic ontogeny using the polymerase chain reaction.
abstract: The expression of 12 cytokine and cytokine receptor genes during mouse thymic ontogeny has been studied using the polymerase chain reaction. The data reveal that IL-2 gene transcription does not begin in the thymus until fetal day (Fd) 16. However, IL-2R beta-chain mRNA was detectable throughout the period of investigation, from Fd 14 to 20. This suggests that the potential for high or intermediate affinity IL-2 binding is present in the thymus before the IL-2 gene is actually expressed. Overall, cytokine gene induction occurred in two distinct patterns. In the first group, represented by IL-1 beta, IL-4, IL-5, IL-6, IL-7, IFN-gamma, and lymphotoxin (lymphotoxin or TNF-beta) there was detectable mRNA present from Fd 14 to 20. IL-1 alpha, IL-2, IL-3, and GM-CSF followed a second pattern in which gene induction was delayed until Fd 16. The expression of IL-7 and IL-2 genes showed an interesting temporal relationship. IL-7 mRNA transcription occurred before IL-2 but diminished from Fd 16 after the onset of IL-2 gene induction. Because these data reflect the in vivo progression of gene expression during T cell ontogeny, they provide a guideline for assessing the physiologic significance of thymocyte responses to cytokines at different stages of fetal development.
authors.affiliation: Nuffield Department of Surgery, University of Oxford, John Radcliffe Hosptial, Headington, England.
authors.forename: R A
authors.initials: RA
authors.lastname: Montgomery
authors.forename: M J
authors.initials: MJ
authors.lastname: Dallman
mesh_terms: D000818:Animals; D001483:Base Sequence; D016207:Cytokines / Q000235:genetics*; D015870:Gene Expression; D005865:Gestational Age; D006321:Heart / Q000196:embryology; D007376:Interleukin-2 / Q000235:genetics; D015851:Interleukin-7 / Q000235:genetics; D008099:Liver / Q000196:embryology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011956:Receptors, Cell Surface / Q000235:genetics*; D015375:Receptors, Interleukin-2 / Q000235:genetics; D013950:Thymus Gland / Q000196:embryology*
chemical_list: D016207:Cytokines; D007376:Interleukin-2; D015851:Interleukin-7; D009841:Oligonucleotides; D011956:Receptors, Cell Surface; D015375:Receptors, Interleukin-2