Intestinal immunisation with Escherichia coli protects rats against Escherichia coli induced cholangitis.
BACKGROUND
Cholangitis, an infection of the biliary tract, is most commonly caused by Gram negative bacteria, particularly Escherichia coli. Factors governing the severity of cholangitis, including the role of biliary IgA, are poorly understood.


OBJECTIVE
The aim of this work was to find out if biliary IgA directed against E coli protects rats against hepatobiliary infection with E coli.


METHODS
Male Sprague-Dawley rats weighing 270-350 grams were used in all of the experiments.


METHODS
At laparotomy, rats were immunised by injecting killed E coli or normal saline (controls) into Peyer's patches. With or without subsequent antigenic boosting (by oral administration of killed E coli), bile was collected at a second laparotomy, and rats were infected by introducing viable E coli into the bile duct. Production of IgA anti-E coli antibody was measured by enzyme linked immunosorbent assay of bile, and the presence of hepatobiliary infection was determined by quantitative culture of liver homogenates.


RESULTS
Systemic infection was present in six of 12 control rats and in one of 24 immunised rats (p = 0.005) after death. There was an inverse correlation between immunisation and E coli colony counts in cultured liver homogenates (p = 0.024).


CONCLUSIONS
The findings suggest that biliary IgA directed against E coli protected rats against hepatobiliary E coli infection and systemic sepsis.
Aagaard
B D
BD
Department of Surgery and Medicine, University of California, San Francisco 94121, USA.
Heyworth
M F
MF
Oesterle
A L
AL
Jones
A L
AL
Way
L W
LW
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D001646:Bile / Q000276:immunology; D015153:Blotting, Western; D002761:Cholangitis / Q000209:etiology* / Q000517:prevention & control; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000150:complications / Q000276:immunology / Q000517:prevention & control*; D007114:Immunization; D007070:Immunoglobulin A / Q000276:immunology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015164:Vaccines, Inactivated / Q000008:administration & dosage
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D015164:Vaccines, Inactivated