IL-15 induces the release of soluble IL-2Ralpha from human peripheral blood mononuclear cells.
The recently identified and cloned cytokine IL-15 shares many of the T-cell and B-cell stimulatory activities of IL-2 and utilizes the beta and gamma chains of the IL-2R for binding and signaling. The present report shows that, like IL-2, IL-15 in a concentration and time-dependent manner causes the release of sIL-2Ralpha from PHA-activated human peripheral blood mononuclear cells. This effect of IL-15 is largely direct and independent of IL-2. Blocking of the IL-2Rbeta chain with the antibody Mik-beta1 prevented the release of sIL-2Ralpha by IL-15 but not by IL-2. IL-7, another cytokine utilizing the gamma chain of the IL-2R, drove the release of sIL-2Ralpha as well. Several clinical conditions are associated with abnormal serum sIL-2Ralpha levels and are also monitored by the measurement of sIL-2Ralpha. The reason for sIL-2Ralpha release is not fully understood. In this study, IL-15, like IL-2 was shown to be a potent inducer of sIL-2Ralpha release in vitro.
Treiber-Held
S
S
Immunophysiology Section, Metabolism Branch, National Cancer Institute, National Institutes of Health , Bethesda, Maryland 20982, USA.
Stewart
D M
DM
Kurman
C C
CC
Nelson
D L
DL
D000911:Antibodies, Monoclonal / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006801:Humans; D019409:Interleukin-15; D015851:Interleukin-7 / Q000494:pharmacology; D007378:Interleukins / Q000494:pharmacology / Q000502:physiology*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008213:Lymphocyte Activation; D010835:Phytohemagglutinins / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000737:chemistry / Q000378:metabolism*; D012995:Solubility; D013997:Time Factors
D000911:Antibodies, Monoclonal; D019409:Interleukin-15; D015851:Interleukin-7; D007378:Interleukins; D010835:Phytohemagglutinins; D015375:Receptors, Interleukin-2