幽门螺杆菌口服疫苗体系优选OA

Objective To optimize the oral vaccine system of Helicobacter pylori(H.pylori).Methods H.pylori adhesin A(HpaA)and urease B subunit(UreB)antigens were prepared.SPF female BALB/c mice were randomly divided into the negative control group(equal volume of normal saline,the same below),antigen group(UreB+HpaA,UreB was 500 μg/mouse,HpaA was 500 μg/mouse),group A[UreB+HpaA+LT(B)5,LT(B)5 was 125 μg/mouse],group B(UreB+HpaA+CpG1018,CpG1018 was 50 μg/mouse,the same below),group C(UreB+HpaA+chitosan,chitosan was 1 600 μg/mouse),group D(UreB+HpaA+CpG1018+sodium decanoate,sodium decanoate was 4 mg/mouse),group E(UreB+HpaA+CpG1018+SNAC,SNAC was 4 mg/mouse),group F(UreB+HpaA+CpG1018+sodium deoxycholate,sodium deoxycholate was 4 mg/mouse),with seven mice in each group,a total of 40 SPF BALB/c mice were randomly divided into the negative control group,simulated vaccine control group(CpG1018+sodium deoxycholate),low-dose group(group F,400 μL/mouse)and high-dose group(group F,800 μL/mouse),with 10 mice in each group,half male and half female,respectively.The mice were immunized on day 0,7,14 and 21,were administered the corresponding dose by gavage,400 μL each time(800 μL in two administrations).Enzyme-linked immunosorbent assay(ELISA)method was used to determine the levels of serum immunoglobulin G(IgG)and intestinal lavage fluid secretory immunoglobulin A(sIgA)of the antigen group and group A-F in mice;the plate method was used to detect the amount of H.pylori colonization in gastric tissue in the negative control group,antigen group and group A-F of mice;mortality,body weight and food consumption in the negative control group,simulated vaccine control group,low-dose group and high-dose group of mice were recorded,and hematoxylin-eosin(HE)staining method was used to observe the pathological morphology of organs and tissues in the negative control group and low-dose group of mice.Results The recombinant plasmid pET29b-HpaA/UreB system was successfully constructed by double enzyme digestion.After purification,the purity of the three batches of antigen samples was at least 91.0%(HpaA)and 91.9%(UreB).The levels of anti UreB specific serum IgG,intestinal sIgA and anti HpaA specific intestinal sIgA in the group F were significantly higher than those in the group B,D and E(P<0.05),and the level of anti HpaA specific serum IgG was significantly higher than that in the group B(P<0.001);compared with the negative control group,the colonization of H.pylori in gastric tissue of mice in the group F was significantly decreased(P<0.05).Compared with the negative control group,the mortality,body weight and food consumption of mice in the simulated vaccine control group,low-dose group and high-dose group were not significantly changed,and the heart,liver,spleen,lung,kidney,stomach and small intestine of mice did not show obvious systemic toxicity and local irritant pathological morphology at the administration site in the low-dose group.Conclusion The optimized CpG1018 adjuvant-sodium deoxycholate oral absorption enhancer assisted HpaA-UreB antigen oral vaccine system can significantly enhance the systemic immune response in mice,reduce the colonization of H.pylori,and is relatively safety.