Differential Stimulatory
Activities of Smooth and Rough
Brucella abortus Lipopolysaccharide in Murine Macrophages
Raheela Akhtar1,2*,YongqunO. He2, Charles B. Larson2, Zafar I.
Chaudhary3 and Mansur ud-Din Ahmad4
1Department of Pathology, University of Veterinary
and Animal Sciences, Lahore-54000, Pakistan; 2Unit of
Laboratory Animal Medicine and Department of Microbiology and
Immunology, University of Michigan Medical School, Ann Arbor, MI
48109, USA; 3Faculty of Veterinary Sciences, Bhaudin
Zakariya University, Multan; 4Department of Epidemiology
and Public Health, University of Veterinary and Animal Sciences,
Lahore-54000, Pakistan
*Corresponding author:
dr_raheela_pathologist@yahoo.com;
teetu_meetu41@yahoo.com
Abstract
Brucella abortus lipopolysaccharide (LPS) was isolated and
purified fromrough (RB51) and smooth
(S2308) strains of Brucella. The LPS
preparations were used to treat murine (RAW 264.7) macrophages in order to study
their differential effects.Treated
macrophages were tested by lysozyme release test (LRT), nitroblue tetrazolium
test (NBT) and nitric oxide (NO) assay, respectively. Rough
Brucella LPS induced significantly
higher levels of lysozyme release, oxidative stress, and nitric oxide in murine
macrophages than smooth Brucella LPS
or combined LPS (rough + smooth LPS). These responses were dose-dependent.
Macrophages treated with rough LPS were more
Brucellacidal than those treated with
smooth LPS. The minimal stimulation of murine macrophages by
Brucella smooth LPS may provide basis
for less active immune responses against smooth strains.