| Helicobacter pylori planting in stomach mucosa is now recognized as the most widespread human pathogen. Approximately half of the world's population is infected. The infection of H. pylori is highly associated with chronic active gastritis, peptic ulcers, gastric adenocarcinoma and lymphoma of the mucosa-associated lymphoid tissue (MALT).In 1994,WHO ranked H. Pylori as I grade carcinogen. Current drug therapies are not practical for global control due to the high cost, problems with patients' compliance and the emergence antibiotic resistant strains. Therefore, Vaccination against H. pylori has been considered to control H. pylori infection. It has been proved that administration of oral urease B subunit antigens together with a mucosal adjuvant can not only induce a series of protective immune reaction but also sweep Hp from stomach of infected mice. So, recombinant vaccine of Hp (rHp} was used in this study.It has been proved that vaccine administered by mucosa can produce effective immune response and prevent or cure Hp infection. In terms of CMIS, all mucosa such as gut, nasal and rectal routs can be used to inoculate vaccine. Intranasal immunization does not expose antigens to low pH and a broad range of degradative enzymes. So it can induce stronger and earlier IgA immune responses at almost all mucosal sites than oral route. The way induced by nasal route is similar to which gut associated lymphoid tissue(GALT) induced. There are rectal follicles but not protease in rectum. Rectal immunization can also induce mucosal immune responses in gastrointestinal tract.However, liquid drugs administered by nasal cavity and rectum have a low bioavailability due to staying a short time. The gel prepared with carbopol has strong bio-adhesion, can prolong contact between drug and mucosa. It may be used in nasal and rectal immunization.Now, studies on immunogenicity of Hp vaccine mainly focus on oral administration with liquid or microparticles. Whereas the vaccine solution administrated orally would be digested and decomposed by the low pH and pepsin. Though microparticle is a popular form, it has a series of significant problems such as low encapsulation rate and possibility of antigen denaturation as a consequence of expose to organic solvents and high temperature. Water-in-oil-in-water type multiple emulsion (w/o/w) in which drug is entrapped in oil droplet can protect drug from pepsin and has lymph taxis. So, it is suitable to protein drugs for oral.In this study, two suitable preparation were made. Firstly, stable rHp gel (Viscid coefficient 8050 centipoise) was prepared. It did not destruct antigenic integrity and induced stronger immune response than rHp solution did after administered by intranasal route or rectal route. Secondly, rHp multiple emulsion(ME) was prepared in two-stage emulsification method. It has a high entrapment efficiency of 98.3%, particle size distributing within 5-7u m , Viscid coefficient of 1432 centipoise. Antigen was stable after Multiple emulsion treated with gastric juice for 0.5-6h. Study on distribution in vivo of ME revealed that ME could stay for a long time in stomach and that antigen concentration in mesentery was increased with time and reached peak at 24h. Antigen in ME was stable after treated with gastric juice for 6h. ME has significantly enhanced the immune efficiency of rHp.In this study, high specific antibodies levels were induced in serum, gastric and intestinal mucosa of BALB/c mice immunized with rHp by oral, rectal and intranasal route. In the meantime, comparing with control group,evident immune protection against Hp was induced. The dose is 10 μ g per mouse of intranasal immunization, 25 μ g per mouse of rectal immunization and 50 μ g per mouse of oral immunization.Specific IgA and IgG antibody secreting cells detected by ELISPOT were discovered in spleen and Peyer'patch of mice immunized with rHp by three routes, which were corresponded with mucosal specific antibodies. RT-PCR of cytokine revealed that IL-4 was mainly expressed...
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