Membrane bound IL-15 is increased on CD14 monocytes in early stages of MS.
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.
Vaknin-Dembinsky
Adi
A
Center for Neurological Diseases, Brigham and Women's Hospital, Harvard Medical, School, Boston Massachusetts 02115, United States.
Brass
Steven D
SD
Brass
Steven
S
Gandhi
Roopali
R
Weiner
Howard L
HL
D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D019409:Interleukin-15 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*; D053647:Receptors, Interleukin-15 / Q000378:metabolism; D012720:Severity of Illness Index
D016207:Cytokines; D019409:Interleukin-15; D053647:Receptors, Interleukin-15