Mouse brain microglia express interleukin-15 and its multimeric receptor complex functionally coupled to Janus kinase activity

J Biol Chem. 1997 Nov 14;272(46):28853-60. doi: 10.1074/jbc.272.46.28853.


The cytokine, interleukin (IL)-15, and the T cell growth factor, IL-2, exhibit a similar spectrum of immune effects and share the IL-2 receptor (IL-2R) subunits IL-2Rbeta and IL-2Rgamma for signaling in hematopoietic cells. Numerous neuroregulatory activities of IL-2 have been suggested, but its expression in the normal central nervous system (CNS) is apparently very low and regionally restricted. We show by RNA and protein detection that IL-15, its specific receptor molecule, IL-15Ralpha, and the signal-transducing receptor subunits, IL-2Rbeta and IL-2Rgamma, are constitutively present in various regions of the developing and adult mouse brain. We further demonstrate, also at the single-cell level, that IL-15 and the components for IL-15Ralpha/IL-2Rbetagamma receptors are expressed by microglia. Tyrosine phosphorylation data are presented showing that IL-15 signaling in microglia involves Janus kinase 1 activity. At doses of 0.1-10 ng/ml, IL-15 affected functional properties of these cells, such as the production of nitric oxide, and supported their growth in culture, suggestive of a role as an autocrine growth factor. Microglial IL-15 could thus play a pivotal role in the CNS and may participate in certain CNS and neuroendocrine functions previously ascribed to IL-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / metabolism*
  • Calcium / metabolism
  • Cells, Cultured
  • Humans
  • Interleukin-15 / genetics
  • Interleukin-15 / metabolism*
  • Janus Kinase 1
  • Mice
  • Microglia / metabolism*
  • Nitric Oxide / biosynthesis
  • Phosphorylation
  • Polymerase Chain Reaction
  • Protein Binding
  • Protein-Tyrosine Kinases / metabolism*
  • RNA, Messenger / genetics
  • Rats
  • Rats, Wistar
  • Receptors, Interleukin-15
  • Receptors, Interleukin-2 / genetics
  • Receptors, Interleukin-2 / metabolism*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Signal Transduction


  • IL15RA protein, human
  • Il15ra protein, mouse
  • Interleukin-15
  • RNA, Messenger
  • Receptors, Interleukin-15
  • Receptors, Interleukin-2
  • Recombinant Proteins
  • Nitric Oxide
  • Protein-Tyrosine Kinases
  • JAK1 protein, human
  • Jak1 protein, mouse
  • Jak1 protein, rat
  • Janus Kinase 1
  • Calcium