Free IL-15 Is More Abundant Than IL-15 Complexed With Soluble IL-15 Receptor-α in Murine Serum: Implications for the Mechanism of IL-15 Secretion.
Endocrinology
; 157(3): 1315-20, 2016 Mar.
Article
em En
| MEDLINE
| ID: mdl-26812159
ABSTRACT
IL-15 is a cytokine that is part of the innate immune system, as well as a proposed myokine released from skeletal muscle during physical exercise that mediates many of the positive physiological effects of exercise. Many of the immune functions of IL-15 are mediated by juxtacrine signaling via externalized IL-15 bound to membrane-associated IL-15 receptor-α (IL-15Rα). Serum and plasma samples also contain measurable concentrations of IL-15, believed to arise from proteolytic cleavage of membrane-associated IL-15/IL-15Rα complexes to generate soluble IL-15/IL-15Rα species. Here, we validate commercial assays that can distinguish the free form of IL-15 and IL-15/IL-15Rα complexes. These assays showed that most (86%) IL-15 in mouse serum resides in the free state, with a minor proportion (14%) residing in complex with IL-15Rα. Given the much shorter half-life of free IL-15 compared with IL-15/IL-15Rα complexes, these findings cast doubt on the currently accepted model for IL-15 secretion from cleavage of membrane-bound IL-15/IL-15Rα and suggest that IL-15 is released as a free molecule by an unknown mechanism.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Membrana Celular
/
Interleucina-15
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article