Cargando…

Mycobacterium tuberculosis Induces Interleukin-32 Production through a Caspase- 1/IL-18/Interferon-γ-Dependent Mechanism

BACKGROUND: Interleukin (IL)–32 is a newly described proinflammatory cytokine that seems likely to play a role in inflammation and host defense. Little is known about the regulation of IL-32 production by primary cells of the immune system. METHODS AND FINDINGS: In the present study, freshly obtaine...

Descripción completa

Detalles Bibliográficos
Autores principales: Netea, Mihai G, Azam, Tania, Lewis, Eli C, Joosten, Leo A. B, Wang, Maorong, Langenberg, Dennis, Meng, Xianzhong, Chan, Edward D, Yoon, Do-Young, Ottenhoff, Tom, Kim, Soo-Hyun, Dinarello, Charles A
Formato: Texto
Lenguaje:English
Publicado: Public Library of Science 2006
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1539091/
https://www.ncbi.nlm.nih.gov/pubmed/16903774
http://dx.doi.org/10.1371/journal.pmed.0030277
Descripción
Sumario:BACKGROUND: Interleukin (IL)–32 is a newly described proinflammatory cytokine that seems likely to play a role in inflammation and host defense. Little is known about the regulation of IL-32 production by primary cells of the immune system. METHODS AND FINDINGS: In the present study, freshly obtained human peripheral blood mononuclear cells were stimulated with different Toll-like receptor (TLR) agonists, and gene expression and synthesis of IL-32 was determined. We demonstrate that the TLR4 agonist lipopolysaccharide induces moderate (4-fold) production of IL-32, whereas agonists of TLR2, TLR3, TLR5, or TLR9, each of which strongly induced tumor necrosis factor α and IL-6, did not stimulate IL-32 production. However, the greatest amount of IL-32 was induced by the mycobacteria Mycobacterium tuberculosis and M. bovis BCG (20-fold over unstimulated cells). IL-32-induced synthesis by either lipopolysaccharide or mycobacteria remains entirely cell-associated in monocytes; moreover, steady-state mRNA levels are present in unstimulated monocytes without translation into IL-32 protein, similar to other cytokines lacking a signal peptide. IL-32 production induced by M. tuberculosis is dependent on endogenous interferon-γ (IFNγ); endogenous IFNγ is, in turn, dependent on M. tuberculosis–induced IL-18 via caspase-1. CONCLUSIONS: In conclusion, IL-32 is a cell-associated proinflammatory cytokine, which is specifically stimulated by mycobacteria through a caspase-1- and IL-18-dependent production of IFNγ.