CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
artículos
Título:
Brucella abortus-infected macrophages modulate T lymphocytes to promote osteoclastogenesis via IL-17.
Autor/es:
GIAMBARTOLOMEI GH; SCIAN R; ACOSTA RODRIGUEZ EV; FOSSATI CA; DELPINO MV
Revista:
AMERICAN JOURNAL OF PATHOLOGY
Editorial:
AMER SOC INVESTIGATIVE PATHOLOGY, INC
Referencias:
Año: 2012 p. 887 - 896
ISSN:
0002-9440
Resumen:
The pathogenic mechanisms of bone loss caused by
Brucella species have not been completely deciphered.
Although T lymphocytes (LTs) are considered
important to control infection, the mechanism of
Brucella-induced T-cell responses to immunopathological
features is not known. We present in vitro and
in vivo evidence showing that Brucella abortusinduced
inflammatory response leads to the activation
of LTs, which further promote osteoclastogenesis.
Pre-activated murine LTs treated with culture supernatant
from macrophages infected with B. abortus
induced bone marrowderived monocytes (BMMs) to
undergo osteoclastogenesis. Furthermore, osteoclastogenesis
was mediated by CD4 T cells. Although B.
abortusactivated T cells actively secreted the proosteoclastogenic
cytokines RANKL and IL-17, osteoclastogenesis
depended on IL-17, because osteoclast
generation induced by Brucella-activated T cells was
completely abrogated when these cells were cultured
with BMMs from IL-17 receptor knockout mice. Neutralization
experiments indicated that IL-6, generated
by Brucella infection, induced the production of proosteoclastogenic
IL-17 from LTs. By using BMMs from
tumor necrosis factor receptor p55 knockout mice, we
also demonstrated that IL-17 indirectly induced osteoclastogenesis
through the induction of tumor necrosis
factor- from osteoclast precursors. Finally, extensive
and widespread osteoclastogenesis was observed in the
knee joints of mice injected with Brucella-activated T
cells. Our results indicate that activated T cells, elicited
by B. abortusinfected macrophages and influenced by the inflammatory milieu, promote the generation of
osteoclasts, leading to bone loss.