Ja. Adachi et al., Serum antibody response induced in mice after oral administration of threedifferent antigens of enterotoxigenic Escherichia coli in enteric coated microparticles, J TRAVEL M, 7(6), 2000, pp. 304-308
Background: Gastric digestion of these antigens plays an important role, de
creasing the ability to deliver antigens to the gut-associated lymphoid tis
sue. To overcome this obstacle, microencapsulated antigens from enterotoxig
enic Escherichia coil (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) f
ormalin-killed whole cell ETEC H10407 (FK-ETEC), (3) crude preparation of c
olonization factor antigen I (CFA/1), or (4) placebo. Serum antibody was me
asured on day 0 and 60 by ELISA.
Results: In group 1 a CTB antibody response was induced in all mice, 3 with
1:10(5) titer and 7 with 1:10(6). These antibodies neutralized cholera tox
in-induced steriodogenesis of Y-1 adrenal cells. In group 2, 8 mice develop
ed a whole H10407 bacteria antibody titer of 1:100, one 1:200 and one showe
d no immune response. In the same group, an anti-CFA/I response was observe
d in 6 mice and anti-LPS in 4 mice as determined by Western blot. All mice
in group 3 showed > 1:10(4) anti-CFA/I antibody titer. Group 4 mice did not
develop an immune response to any ETEC antigens.
Conclusion: Microencapsulation appears to be a suitable approach for oral v
accination against ETEC and Vibrio cholerae.