Previous Article | Next Article ![]()
Infect. Immun., Apr 1995, 1409-1414, Vol 63, No. 4
J Lin and TA Ficht
Brucella abortus is a facultative, intracellular, pathogenic bacterium that
replicates within macrophages and resists macrophage microbicidal
mechanisms. To study gene expression and to elucidate the defense
mechanisms used by B. abortus to resist destruction within macrophages,
protein synthesis by B. abortus was examined by pulse-labeling techniques
during intracellular growth within J774A.1, a macrophage- like cell line.
Prominent changes observed include increased synthesis of Brucella proteins
with estimated molecular masses of 62, 28, 24, and 17 kDa. The 62-kDa
protein was identified by immunoprecipitation analysis as Hsp62, a GroEL
homolog. A protein of 60 kDa was expressed during acid shock and may
represent a modified form of Hsp62. The 28- and 17-kDa proteins have not
been observed under any in vitro stress condition and presumably represent
macrophage-specific induction. The 24-kDa protein comigrates with an
unidentified protein induced by acid shock, designated Asp24. Expression of
Asp24 is optimal at pH values below 4.0 and within the first 3 h following
a shift from pH 7.3 to 3.8. This corresponds directly with a period of
optimal bacterial survival at a reduced pH and suggests an active role for
this protein in resistance to such environments. The identification of
these gene products and the mechanisms controlling their expression is an
important step in understanding the resistance of Brucella spp. to
intracellular destruction within macrophages.
Copyright © 1995, American Society for Microbiology
Protein synthesis in Brucella abortus induced during macrophage infection
Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|