Issue |
Vet. Res.
Volume 34, Number 3, May-June 2003
|
|
---|---|---|
Page(s) | 307 - 316 | |
DOI | https://doi.org/10.1051/vetres:2003006 | |
How to cite this article | Vet. Res. (2003) 307-316 |
DOI: 10.1051/vetres:2003006
Recombinant bovine soluble CD14 reduces severity of experimental Escherichia coli mastitis in mice
Jai-Wei Leea, Max J. Paapeb and Xin Zhaoaa Department of Animal Science, McGill University, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada
b Immunology and Disease Resistance Laboratory, USDA-ARS, Beltsville, MD-20901, USA
(Received 15 October 2002; accepted 9 December 2002)
Abstract
Endotoxin, or lipopolysaccharide (LPS), is responsible for pathogenesis of infections
induced by Gram-negative bacteria, such as E. coli. The cellular response to LPS is
modulated by interactions among LPS, LPS-binding protein (LBP) and CD14. Accumulated
evidence shows that the soluble form of CD14 (sCD14) competes with membrane-bound
CD14 (mCD14) for LPS and plays a pivotal role in regulating bacterial infection
and septic shock caused by Gram-negative bacteria. Recombinant bovine sCD14 (rbosCD14)
was produced by transfected insect sf/9 cells and its biological function was evaluated
in mice. Eighty-one 8-week old BALB/cj female mice were randomly assigned to two groups,
and injected intraperitoneally with either LPS (8
g/g of body weight,
n = 41) or LPS
plus rbosCD14 (6.8
g/g of body weight,
n = 40). Survival rate at 24 h after injection
for mice injected with either LPS or LPS plus rbosCD14 was 30 and 72%, respectively
(
P < 0.01). At 48 h survival rate was 7 and 37%, respectively (
P < 0.01). To investigate
the protective effect of rbosCD14 on experimentally induced mastitis in mice,
two abdominal contralateral mammary glands of 7 lactating BALB/cj mice were injected
through the teat canal with 10-20 colony-forming units (CFU) of Escherichia coli.
One gland simultaneously received rbosCD14 (6
g) and the other saline. At 24 h after
challenge, glands that received rbosCD14 had less swelling and hemorrhaging, significantly
lower bacterial counts (
P < 0.05) and lower concentrations of TNF-
(
P < 0.05).
Results indicate that rbosCD14 is biologically functional and reduces mortality in mice
from endotoxin shock and severity of intramammary infection by E. coli.
Key words: mastitis / CD14 / LPS / Escherichia coli / TNF-

Correspondence and reprints: Xin Zhao Tel.: (1) 514 398 7975; fax: (1) 514 398 7964;
e-mail: Zhao@macdonald.mcgill.ca
© INRA, EDP Sciences 2003