INVESTIGADORES
ZORREGUIETA Angeles
artículos
Título:
BmaC, a novel autotransporter of Brucella suis, is involved in bacterial adhesion to host cells.
Autor/es:
POSADAS, D. M.; RUIZ-RANWEZ, M.V.; BONOMI, H.; MARTÍN, F.A.; ZORREGUIETA, A
Revista:
CELLULAR MICROBIOLOGY (PRINT)
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2012 vol. 14 p. 965 - 982
ISSN:
1462-5814
Resumen:
Brucella is an intracellular pathogen responsible of a zoonotic
disease called brucellosis. Brucella survives and proliferates within
several types of phagocytic and non-phagocytic cells. Like in other
pathogens, adhesion of brucellae to host surfaces was proposed to be an
important step in the infection process. Indeed, Brucella has the
capacity to bind to culture human cells and key components of the
extracellular matrix, such as fibronectin. However, little is known
about the molecular bases of Brucella adherence. In an attempt to
identify bacterial genes encoding adhesins, a phage display library of
Brucella suis was panned against fibronectin. Three fibronectin-binding
proteins of B. suis were identified using this approach. One of the
candidates, designated BmaC was a very large protein of 340 kDa that is
predicted to belong to the type I (monomeric) autotransporter family.
Microscopy studies showed that BmaC is located at one pole on the
bacterial surface. The phage displaying the fibronectin-binding peptide
of BmaC inhibited the attachment of brucellae to both, HeLa cells and
immobilized fibronectin in vitro. In addition, a bmaC deletion mutant
was impaired in the ability of B. suis to attach to immobilized
fibronectin and to the surface of HeLa and A549 cells and was
out-competed by the wild-type strain in co-infection experiments.
Finally, anti-fibronectin or anti-BmaC antibodies significantly
inhibited the binding of wild-type bacteria to HeLa cells. Our results
highlight the role of a novel monomeric autotransporter protein in the
adhesion of B. suis to the extracellular matrix and non-phagocytic cells
via fibronectin binding.