Cloning the full-length IL-2/15 receptor-β cDNA sequence from mouse brain: evidence of enrichment in hippocampal formation neurons

• Published in: Regulatory peptides 2001-04, Vol.98 (1), p.77-87
• Main Authors: Petitto, John M, Huang, Zhi
• Format: Article
• Language: English
• Subjects: Anchored PCR; Animals; Biological and medical sciences; Brain - physiology; Cells, Cultured; Cloning, Molecular; Cytokines; DNA, Complementary; Fundamental and applied biological sciences. Psychology; Genes; Hippocampus - cytology; Hippocampus - physiology; Humans; In Situ Hybridization - methods; Interleukin-2 - metabolism; Interleukin-2 Receptor beta Subunit; Isolated neuron and nerve. Neuroglia; Limbic; Mice; Mice, Inbred BALB C; Mice, SCID; Neuroimmunology; Neuronal differentiation; Neurons - physiology; Polymerase Chain Reaction; Prosencephalon - physiology; Rats; Receptors, Interleukin - genetics; Receptors, Interleukin - metabolism; Sequence Analysis, DNA; Vertebrates: nervous system and sense organs
• ISSN: 0167-0115; 1873-1686
• DOI: 10.1016/S0167-0115(00)00229-9

Numerous studies have implicated interleukin-2 (IL-2) in various brain processes, and more recently, several studies have also attributed neurobiological actions to interleukin-15 (IL-15). On lymphocytes, receptors for IL-2 and IL-15 share a common subunit, the IL-2/15 receptor-β (IL-2/15Rβ) that is essential for intracellular signaling. Although a short segment of IL-2/15Rβ has been cloned (0.35 kb) from normal brain cells, attempts to isolate the full-length cDNA have been unsuccessful, suggesting the possibility that the genes expressed by brain cells and lymphocytes may differ. Using conventional and anchored PCR cloning strategies, we isolated the full-length cDNA of IL-2/15Rβ (2038 bp) from well-perfused, normal mouse forebrain. The coding sequence and the adjacent 5′ and 3′ UTR sequences from brain and lymphocyte were found to be fully homologous. Although evidence of expression of IL-2/15Rβ can be found in many brain regions using PCR, clear evidence of gene expression by in situ hybridization was detectable only in the hippocampal formation, habenula and piriform cortex. This same pattern of mRNA expression in situ was also observed for the common γ subunit shared by IL-2 and IL-15. In the hippocampus, IL-2/15Rβ expression was localized to neurons by high resolution in situ hybridization and evidence of IL-2 receptor protein expression was also detected by radioligand receptor binding using hippocampal homogenates. Comparison of undifferentiated and differentiated, immortalized H19-7 hippocampal neurons showed that IL-2/15Rβ was constitutively expressed across disparate stages of hippocampal neuronal differentiation. These data indicate that IL-2/15Rβ may serve to modulate neuronal processes in the hippocampus and associated limbic brain regions.