Membrane bound IL-15 is increased on CD14 monocytes in early stages of MS

J Neuroimmunol. 2008 Mar;195(1-2):135-9. doi: 10.1016/j.jneuroim.2008.01.016. Epub 2008 Apr 1.


IL-15 is a pro-inflammatory cytokine whose three-dimensional structure is similar to that of IL-2. IL-2 and IL-15 have similar as well as distinct biological functions. An active form of IL-15 that is membrane bound has also been described. Furthermore, IL-15 is known to play a role in autoimmune diseases. We thus investigated the expression of membrane bound IL-15 on monocytes (CD14+ cells) and studied its effect on T cell activation in MS patients. We found that unstimulated CD14+ cells from relapsing remitting MS patients had increased membrane bound IL-15. Those with high surface levels of IL-15 on monocytes were in the early stages of the disease. In addition, we found that T cells of MS patients had enhanced responsiveness to IL-15 and there was increased expression of IL-15 receptor on CD4+ T cells. Thus, IL-15 may be an important cytokine that drives Th1 responses early in the course of the disease and could serve as a target for immunotherapy and as an early marker in the immunologic staging of MS.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • CD4-Positive T-Lymphocytes / drug effects*
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / metabolism*
  • Cells, Cultured
  • Cytokines / metabolism
  • Enzyme-Linked Immunosorbent Assay / methods
  • Female
  • Flow Cytometry / methods
  • Humans
  • Interleukin-15 / pharmacology*
  • Lymphocyte Activation / drug effects
  • Male
  • Middle Aged
  • Multiple Sclerosis / pathology*
  • Receptors, Interleukin-15 / metabolism
  • Severity of Illness Index


  • Cytokines
  • Interleukin-15
  • Receptors, Interleukin-15