Aluminum Nanoparticles Are Used As Lung Mucosal Vaccine Adjuvant-delivery System(VADS) To Trigger Effective Systemic And Mucosal Immunity In Mice

The lung mucosa is one of the most important sites for mucosal vaccination.We used an established mouse model of alumina nanoparticle(ANs)lung tracheal inhalation,and loaded ANs with ovalbumin(OVA)model antigen for lung inoculation to verify that aluminum nanocarriers stimulated strong and effective mucosal immune expression.Objective: To investigate the safety and immune induction efficacy of alumina nanoparticles as an adjuvant delivery system for pulmonary mucosal vaccines.Method: Dynamic light scattering,electrophoretic scattering,scanning electron microscope and transmission electron microscope were used to characterize the particle size and morphology of ANs.Coomassie brilliant blue method was used to measure the antigen release of ANs-OVA in vitro.In vitro cells,laser confocal microscopy(LSCM qualitative)and flow cytometry(FACS quantitative)were used to analyze the ability of antigen-presenting cells(APC)to take up ANs,and to investigate the maturation stimulation of APC and APC molecules by aluminum nanocarrier drugs expression.In the in vivo experiment,the distribution and aggregation of ANs after entering the body were investigated by small animal live imaging technology and tissue frozen sections.Finally,the immune expression of mice after lung inoculation with different immune preparations was investigated,and it is compared with traditional aluminum phosphate adjuvant subcutaneously.Results: ANs have a particle size of about 25 nm,a potential of about 30 m V,and a nearly spherical shape.In vitro cell experiments also proved that compared with traditional adjuvant aluminum phosphate particles,ANs can effectively promote the uptake of APC.In vivo tracking shows that nano-alumina effectively reaches the lungs and dissociates to the remote lymph nodes within a certain period of time,which provides preliminary experimental basis for exerting systemic mucosal immunity.In mouse lung immunization experiments,ANs not only did not produce too many side effects,but also induced strong specific immunity and extensive mucosal immune response.The results of enzyme-linked immunosorbent assay(ELISA)showed that the immunized mice produced high levels of Ig G in the serum after two immunizations.The saliva,nasal mucosal lavage fluid,BALF and vaginal secretions of the mice all produced high levels of Ig A,but the small intestine washing fluid and fecal diluent did not show the immune effect.In addition,compared with traditional aluminum adjuvants,high levels of Ig G2 a and IFN-γ were also detected in the serum and splenic lymphocyte culture supernatant of mice vaccinated with ANs,indicating that lung inoculation with ANs can effectively promote balance Th1/Th2 immune response.Conclusions: These results indicate that ANs-OVA can induce Th1/Th2 immune response through pulmonary administration,and can induce systemic and mucosal immune responses.Therefore,ANs is expected to be an effective lung mucosal vaccine adjuvant-delivery system(VADS).