Tuberculous granuloma formation is enhanced by a mycobacterium virulence determinant.
PLoS Biol
; 2(11): e367, 2004 Nov.
Article
em En
| MEDLINE
| ID: mdl-15510227
ABSTRACT
Granulomas are organized host immune structures composed of tightly interposed macrophages and other cells that form in response to a variety of persistent stimuli, both infectious and noninfectious. The tuberculous granuloma is essential for host containment of mycobacterial infection, although it does not always eradicate it. Therefore, it is considered a host-beneficial, if incompletely efficacious, immune response. The Mycobacterium RD1 locus encodes a specialized secretion system that promotes mycobacterial virulence by an unknown mechanism. Using transparent zebrafish embryos to monitor the infection process in real time, we found that RD1-deficient bacteria fail to elicit efficient granuloma formation despite their ability to grow inside of infected macrophages. We showed that macrophages infected with virulent mycobacteria produce an RD1-dependent signal that directs macrophages to aggregate into granulomas. This Mycobacterium-induced macrophage aggregation in turn is tightly linked to intercellular bacterial dissemination and increased bacterial numbers. Thus, mycobacteria co-opt host granulomas for their virulence.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ranidae
/
Tuberculoma
/
Tuberculose
/
Infecções por Mycobacterium
/
Mycobacterium tuberculosis
Limite:
Animals
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article