Abstract
IL-15 is a short chain, four-α helix cytokine that shares some biological function with IL-2. One striking difference between IL-2 and IL-15 is the ability of monocytes to express IL-15 on their cell surface after activation. In the current study we have investigated the ability of human monocyte cell surface IL-15 to participate in reverse signaling. Cross-linking anti-IL-15 Abs were used as a surrogate ligand for surface IL-15 engagement. Ligation of cell surface-expressed IL-15 induced monocyte adhesion that required the activity of small m.w. GTPases. Reverse signals through surface IL-15 activated the Rho-GTPase Rac3. In addition, engagement of cell surface IL-15 was found to activate a number of signaling pathways, including both extracellular signal-regulated kinase 1/2 and p38, and resulted in the secretion of IL-8. IL-8 production required mitogen-activated protein kinase activity. Thus, the current study has established that cell surface IL-15 is more than just a ligand; it can function as a receptor and participate in reverse signaling that results in cellular adhesion and production of inflammatory cytokines.
Original language | English (US) |
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Pages (from-to) | 4225-4234 |
Number of pages | 10 |
Journal | Journal of Immunology |
Volume | 172 |
Issue number | 7 |
DOIs | |
State | Published - Apr 1 2004 |
Externally published | Yes |
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology