Release of sIL-2R alpha from and activation of native human peripheral blood mononuclear cells by recombinant IL-15.
The cytokine interleukin (IL)-15 shares several activities with IL-2. Both cytokines induced expression of cell-surface IL-2R alpha (CD25) on freshly isolated human peripheral blood mononuclear cells (PBMC) in the absence of other exogenous stimuli. They also stimulated the release of soluble IL-2R alpha and induced proliferation of these cells in 1-week cultures in a time- and dose-dependent manner. Recombinant IL-7 could also induce the expression of CD25, although sIL-2R alpha was released at only low levels. In monocyte-depleted PBMC the sIL-2R alpha release was minimal. When isolated T cells or non-T cells were stimulated by rIL-15 or rIL-2, cell surface CD25 was expressed, but released sIL-2R alpha was undetectable. On stimulation with rIL-15, more than 80% of all natural killer cells expressed CD25 and more CD8br+ lymphocytes were positive for CD25 compared to stimulation by rIL-2. These results may be clinically relevant because several diseases are associated with high serum levels of sIL-2R alpha which may he not only due to IL-2 but also due to IL-15 stimulation.
Treiber-Held
S
S
Immunophysiology Section, Metabolism Branch, National Cancer Institute, Bethesda, Maryland 20892, USA.
Stewart
D M
DM
Barraclough
H A
HA
Kurman
C C
CC
Nelson
D L
DL
D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D019409:Interleukin-15; D007376:Interleukin-2 / Q000494:pharmacology; D007378:Interleukins / Q000494:pharmacology*; D007399:Interphase / Q000187:drug effects / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects*; D012333:RNA, Messenger / Q000032:analysis; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013997:Time Factors; D015854:Up-Regulation / Q000276:immunology
D019409:Interleukin-15; D007376:Interleukin-2; D007378:Interleukins; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins