Induction of intestinal IgA and IgG antibodies preventing adhesion of verotoxin-producing Escherichia coli to Caco-2 cells by oral immunization with liposomes.
OBJECTIVE
To examine the efficacy of liposome oral administration to induce systemic and mucosal immune responses against verotoxin-producing Escherichia coli (VTEC) and the effect of the induced antibodies on the binding of the bacteria to Caco-2 cells.


RESULTS
Mice were immunized orally with VTEC antigen and monophosphoryl lipid A (MPL)-containing liposomes composed of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylserine and cholesterol (1 : 1 : 2, molar ratio) (PS-liposome). After immunization, significant IgA and IgG responses to VTEC were induced in both serum and the intestinal lavage fluid in all mice tested. Furthermore, anti-VTEC IgA and IgG antibodies in the lavage fluid effectively inhibited the adhesion of VTEC to Caco-2 cells.


CONCLUSIONS
Oral immunization with liposome-associated E. coli O157:H7 antigen can induce significant systemic and mucosal antibody responses against the bacterial antigen and antibodies produced in the intestinal tract, thus functioning as inhibitors for preventing VTEC infection.


CONCLUSIONS
Oral PS-liposome vaccines containing MPL have the potential usefulness for the induction of a protective mucosal immune response against intestinal diseases.
Tana
Laboratory of Veterinary Immunology, Division of Veterinary Science, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka, Japan.
Watarai
S
S
Isogai
E
E
Oguma
K
K
D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001422:Bacterial Adhesion; D001427:Bacterial Toxins / Q000096:biosynthesis; D018938:Caco-2 Cells; D002478:Cells, Cultured; D004926:Escherichia coli / Q000276:immunology* / Q000472:pathogenicity; D022361:Escherichia coli Vaccines / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D016233:Immunotherapy, Active; D007413:Intestinal Mucosa / Q000276:immunology*; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D022603:Shiga Toxins / Q000096:biosynthesis
D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D022361:Escherichia coli Vaccines; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008081:Liposomes; D022603:Shiga Toxins