LPS pretreatment by the oral route protects against sepsis induced by cecal ligation and puncture. Regulation of proinflammatory response and IgM anti-LPS antibody production as associated mechanisms.
OBJECTIVE
To explore the efficacy of prophylactic oral lipopolysaccharide (LPS) in sepsis induced by cecal ligation and puncture (CLP).


METHODS
Male Balb/c mice. LPS serotype O55: B5


METHODS
Mice were treated every 4 days for a total of 5 times with 50 mug of LPS by intraperitoneal (IP) or oral (O) routes. Treatment was stopped one week prior to CLP. Control (C) groups received the vehicle orally, and sham (S) groups were used as reference.


METHODS
Histopathology was performed to determine inflammation in liver and lung. Serum cytokines were measured by ELISA, and TNFalpha tissue expression by RTPCR. Antibodies against LPS were measured by ELISA.


RESULTS
Administration of LPS by the oral route significantly increased survival (p<0.05) of mice in association with a reduction of Kupffer cells in liver, pulmonary edema in lung, shorter or delayed TNFalpha expression in target organs, a trend to decreased IFN gamma and increased IL-10 serum levels, and a notable increase in the production of specific IgM anti-LPS antibodies.


CONCLUSIONS
LPS by oral route protected against CLP. The underlying mechanisms could be the modulation of the proinflammatory response and an increased production of IgM anti-LPS antibodies.
Márquez-Velasco
R
R
Ciencias Biológicas, UAM-Iztapalapa, Mexico City, Mexico.
Massó
F
F
Hernández-Pando
R
R
Montaño
L F
LF
Springall
R
R
Amezcua-Guerra
L M
LM
Bojalil
R
R
D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D016207:Cytokines / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis*; D008026:Ligation; D008070:Lipopolysaccharides / Q000008:administration & dosage* / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018805:Sepsis / Q000517:prevention & control*; D015996:Survival Rate
D000907:Antibodies, Bacterial; D016207:Cytokines; D007075:Immunoglobulin M; D008070:Lipopolysaccharides