Serum antibody response induced in mice after oral administration of three different antigens of enterotoxigenic Escherichia coli in enteric coated microparticles.
BACKGROUND
Gastric digestion of these antigens plays an important role, decreasing the ability to deliver antigens to the gut-associated lymphoid tissue. To overcome this obstacle, microencapsulated antigens from enterotoxigenic Escherichia coli (ETEC) were evaluated for oral immunization of mice.


METHODS
Four groups of 10 each received 3 series of 3 doses each of (1) B subunit of cholera toxin (CTB), similar to heat-labile toxin of ETEC, (2) formalin-killed whole cell ETEC H10407 (FK-ETEC), (3) crude preparation of colonization factor antigen I (CFA/I), or (4) placebo. Serum antibody was measured on day 0 and 60 by ELISA.


RESULTS
In group 1 a CTB antibody response was induced in all mice, 3 with 1:105 titer and 7 with 1:106. These antibodies neutralized cholera toxin-induced steriodogenesis of Y-1 adrenal cells. In group 2, 8 mice developed a whole H10407 bacteria antibody titer of 1:100, one 1:200 and one showed no immune response. In the same group, an anti-CFA/I response was observed in 6 mice and anti-LPS in 4 mice as determined by Western blot. All mice in group 3 showed > 1:104 anti-CFA/I antibody titer. Group 4 mice did not develop an immune response to any ETEC antigens.


CONCLUSIONS
Microencapsulation appears to be a suitable approach for oral vaccination against ETEC and Vibrio cholerae.
Adachi
J A
JA
Center for Infectious Diseases, University of Texas-Houston Medical School and School of Public Health, Houston, Texas, USA.
Jiang
Z
Z
Cox
M
M
Wood
L
L
DuPont
H L
HL
Mathewson
J J
JJ
D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial; D002772:Cholera Toxin / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D003967:Diarrhea / Q000382:microbiology / Q000517:prevention & control*; D004339:Drug Compounding; D016503:Drug Delivery Systems; D004926:Escherichia coli / Q000276:immunology*; D007114:Immunization; D008689:Methacrylates; D051379:Mice; D008813:Mice, Inbred ICR
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D008689:Methacrylates; C008384:methacrylic acid; D002772:Cholera Toxin