Reduced bacterial dissemination and liver injury in CD14-deficient mice following a chronic abscess-forming peritonitis induced by Bacteroides fragilis.
The CD14 myelomonocytic differentiation antigen plays a major role in acute Gram-negative infections with Escherichia coli; however, its role in chronic infections has not yet been analyzed. To address this question, we studied the role of CD14 in a chronic abscess-forming peritonitis, induced by Bacteroides fragilis. B. fragilis (3x10(8) CFU/ml) were resuspended in a liquid nutrient agar and injected into the peritoneal cavity of CD14-deficient (CD 14-/-) and normal C57BL/6J (CD 14+/+) mice, respectively. After 3 days there was a severe phlegmonous intra-abdominal inflammation in both groups. After 7 days an abscess-forming peritonitis developed and by 14 days the infectious foci were compartimentalized. These observations were indistinguishable between CD14-/- and CD14+/+ mice. Although no differences were seen in abscess formation, CD14-/- mice were able to clear B. fragilis more efficiently from the blood than CD14+/+ mice. After 3, 7, and 14 days blood cultures were B. fragilis positive in 11% (1/9), 20% (2/10), and 0% (0/9) in CD14-/-compared with 90% (9/10), 78% (7/9), and 20% (2/10) in CD14+/+ mice, respectively (P<0.05). Furthermore, although the infection resulted in hepatocellular necrosis and severe hepatitis in both groups, at day 14 the liver cell damage was more severe in CD14+/+ than in CD14-/- mice (P<0.05). These results show that the chronic abscess formation induced by B. fragilis capsular polysaccharides is CD14 independent; however, bacterial clearance and/or dissemination and liver cell damage are at least partially influenced by CD14-dependent mechanisms.
Woltmann
A
A
Department of Surgery, Medical University of Luebeck, Germany. Woltmann@medinf.mu-luebeck.de
Gangloff
S C
SC
Bruch
H P
HP
Rietschel
E T
ET
Solbach
W
W
Silver
J
J
Goyert
S M
SM
D000038:Abscess / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D016470:Bacteremia / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D001442:Bacteroides Infections / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D001441:Bacteroides fragilis / Q000276:immunology*; D002908:Chronic Disease; D004195:Disease Models, Animal; D007958:Leukocyte Count; D018950:Lipopolysaccharide Receptors / Q000276:immunology*; D008099:Liver / Q000293:injuries* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010538:Peritonitis / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology
D018950:Lipopolysaccharide Receptors