IL-15Ralpha recycles and presents IL-15 In trans to neighboring cells.
We report intriguing aspects of the contribution of IL-15Ralpha to IL-15 functions. Consistent with high-affinity interactions between IL-15 and IL-15Ralpha, these two molecules form stable complexes on the cell surface of activated monocytes. The formation of IL-15/IL-15Ralpha complexes on cell surfaces induces a trans-endosomal recycling of IL-15 leading to the persistence of surface-bound IL-15 due to the constant reappearance of IL-15 on plasma membranes. This complex contributes to the long survival of T cells expressing IL-15Ralpha after IL-15 withdrawal. Finally, these complexes on activated monocytes present IL-15 in trans to target cells such as CD8(+) T cells that express only IL-2/15Rbeta and gammac upon cell-cell interaction.
Dubois
Sigrid
S
Metabolism Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Mariner
Jennifer
J
Waldmann
Thomas A
TA
Tagaya
Yutaka
Y
D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D002455:Cell Division; D002460:Cell Line; D004705:Endocytosis; D006801:Humans; D019409:Interleukin-15 / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000502:physiology; D009000:Monocytes / Q000502:physiology; D053647:Receptors, Interleukin-15; D015375:Receptors, Interleukin-2 / Q000378:metabolism*; D015398:Signal Transduction
C508024:IL15RA protein, human; D019409:Interleukin-15; D053647:Receptors, Interleukin-15; D015375:Receptors, Interleukin-2