NK cells provide helper signal for CD8+ T cells by inducing the expression of membrane-bound IL-15 on DCs

Barbara Morandi, Lorenzo Mortara, Paolo Carrega, Claudia Cantoni, Gregorio Costa, Roberto S. Accolla, Maria Cristina Mingari, Silvano Ferrini, Lorenzo Moretta, Guido Ferlazzo

Research output: Contribution to journalArticle


NK cell recognition of cells that do not express or express low amounts of MHC class I molecules results not only in direct killing of target cells but also in the generation of specific T cell responses consequent to the induction of dendritic cell (DC) activation. While IL-12 production by NK cell-activated DCs is generally thought to play a critical role, a similar DC-mediated NK cell help has been reported also in IL-12-knockout mice. Here, we show that human NK cells can induce on DC surface membrane, via IFN-γ secretion, the expression of high levels of IL-15. Remarkably, we show that DC expression of this membrane-bound form of IL-15, which is only partially associated with IL-15R molecules, is essential to promote specific CD8+ T lymphocyte response in the absence of DC-derived IL-12.

Original languageEnglish
Pages (from-to)599-606
Number of pages8
JournalInternational Immunology
Issue number5
Publication statusPublished - 2009



  • CD8 lymphocytes
  • Dendritic cells
  • IL-15 receptor alpha
  • Membrane-bound IL-15
  • NK cells

ASJC Scopus subject areas

  • Immunology

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