BALB/c mice were randomly divided into nine groups and immunized by (1)PBS alone, (2)
chitosan solution alone, (3)
chitosan particles alone, (4)H.pylori
antigen alone, (5)H.pylori
antigen plus
chitosan solution, (6)H.pylori
antigen plus
chitosan particles, (7)H.pylori
antigen plus
cholera toxin (CT), (8)H.pylori
antigen plus
chitosan solution and CT, (9)H.pylori
antigen plus
chitosan particles and CT orally respectively once a week for four weeks. At 4 weeks after the last immunization, mice were challenged by alive H.pylori (1x10(9) CFU/mL) twice at two days intervals. Before and after the challenge, mice were killed in batches and the H.pylori-
infection in gastric mucosa was detected by H.pylori culture and
Giemsa stain. ELISA and HE
stain were used to detect
IL-2,
IL-4,
IL-10 levels and pathologic change in gastric mucosa.
RESULTS: (1)In the groups with
chitosan as an adjuvant, 60% mice could achieve immunological protection, which was consistent with using CT as an adjuvant (58.33%), and was more than that when using H.pylori
antigen alone or without H.pylori
antigen. (2)After challenge, the
IL-2 levels in gastric mucosa in the groups with adjuvants were significantly higher than those in the control group (P<0.001-0.05). Moreover,
IL-2 levels in the groups with adjuvants after challenge were significantly higher than those before challenge (P<0.05). Before challenge, the
IL-10 and
IL-4 levels in gastric mucosa were significantly higher in the groups with
chitosan as adjuvant than those in non-adjuvant groups (P<0.05). After challenge,
IL-10 levels were significantly higher in the groups with
chitosan particles as adjuvant than those in other groups (P<0.05);
IL-4 levels were significantly higher in the groups with
chitosan particles as an adjuvant than those in the group with CT as an adjuvant, and those in the group with
chitosan solution as an adjuvant were significantly higher than those in control group, non-adjuvant group and the groups with CT (P<0.05).
IL-10 and
IL-4 in the groups with adjuvants after challenge were significantly lower than those before challenge (P<0.05). (3)The degree of
inflammation in gastric mucosa was significantly lower in the groups with
chitosan and
chitosan particles as adjuvant than those with CT as adjuvant(P<0.05).
CONCLUSION: (1)H.pylori
vaccine with
chitosan as an adjuvant has the immune protective effect against H.pylori
infection. (2)H.pylori
vaccine with
chitosan as an adjuvant could reverse the inhibition of Th2 induced by H.pylori
infection and recover the Th1/Th2 imbalance, which might contribute to the immune protection against H.pylori. (3)The rate of
gastritis induced by H.pylori
vaccine with
chitosan as adjuvant was significantly lower than those with CT as adjuvant.