Analysis of cytokine gene expression during fetal thymic ontogeny using the polymerase chain reaction

• Published in: The Journal of immunology (1950) Vol. 147; no. 2; pp. 554 - 560
• Main Authors: Montgomery, RA, Dallman, MJ
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Assoc Immnol 15.07.1991; American Association of Immunologists
• Subjects: Animals; Base Sequence; Biological and medical sciences; Cytokines - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression; Gestational Age; Heart - embryology; Interleukin-2 - genetics; Interleukin-7 - genetics; Liver - embryology; Mice; Mice, Inbred BALB C; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Oligonucleotides - chemistry; Polymerase Chain Reaction; Receptors, Cell Surface - genetics; Receptors, Interleukin-2 - genetics; Thymus Gland - embryology; Thymus gland; Thymocyte; Rodentia; Cytokine; Gene expression; Northern blotting; Polymerase chain reaction; Vertebrata; Mammalia; Gene; Mouse; T-Lymphocyte; Development; Fetus
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.147.2.554

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.