ABSTRACT
Purpose@#Brucellosis as a worldwide zoonotic illness affect domestic animals and humans doesn’t have any vaccine for the prevention of infection in humans yet. The aim of this study was to evaluate the specific immune response following the administration of glycine nanoparticles as adjuvant and delivery system of a chimeric antigen contained trigger factor, Omp31, and Bp26 in murine model. @*Materials and Methods@#The chimeric antigen of Brucella was cloned and expressed in Escherichia coli (E. coli) BL21 (DE3). Purification and characterization of recombinant protein was conducted through Ni-NTA (nickel-nitrilotriacetic acid) agarose, SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis), and Western blot. Nanoparticle characteristics including morphology, particle size distribution, zeta potential, protein retention rate, and release rate were measured in vitro. Subsequently, nanoparticle contained antigen was administered to mice and blood sample was taken to measured the antibody level. @*Results@#The protein retention in the nanoparticles was successfully done and the nanoparticle characteristics were appropriate. The average size of glycine particles containing antigen was about 174 nm, and the absorption of protein was approximately 61.27% of the initial value, with a release rate of approximately 70% after 8 hours. Enzyme-linked immunosorbent assay result proved that the immunized sera of mice which were administered with nano-formula contains high levels of antibodies (immunoglobulin G) against recombinant chimeric antigen and also a high level of mucosal antibody (immunoglobulin A) in the oral group, which showed a desirable immunity against Brucella. @*Conclusion@#The results showed that chimeric antigen-loaded glycine nanoparticles can act as a vaccine candidate for inducing the cellular and humoral immune response against brucellosis.
ABSTRACT
Background: Enterohemorrhagic Escherichia coli [EHEC] O157:H7 is an infectious zoonotic pathogen causing human infections. These infections, in some cases, can lead to hemolytic uremic syndrome and its life-threatening complications and even death worldwide. The first intimate bacterial adhesion, intimin [I], with its own receptor translocated intimin receptor [Tir] and E. coli secreted protein A, acting as Tir conduit, are highly immunogenic proteins for vaccine development against E. coli O157:H7
Methods: A chimeric trivalent recombinant protein was previously found to be a suitable strategy for developing vaccines against E. coli O157:H7. In this study, the recombinant EIT [rEIT] was used to design a protective EHEC nasal nanovaccine. Chitosan and its water-soluble derivative, trimethylated chitosan [TMC], as muco-adhesive biopolymers, are good candidates for preparation of nanovaccines. Using the electrospraying technique, as a novel method, we could obtain particles of rEIT loaded with chitosan and TMC on a nanometer scale. Mice were immunized with intranasal administration or intrapretoneal injection of rEIT
Results: The rEIT-specific immune responses [IgG and IgA] were measured by indirect ELISA. Only nasal administration of chitosan electrospray and TMC formulation produced significant secretion IgA. Intranasal administration of nanovaccine reduced the duration of bacterial fecal shedding on mice challenged with E. coli O157:H7
Conclusion: Since development of mucosal vaccines for the prevention of infectious diseases requires efficient antigen delivery; therefore, this research could be a new strategy for developing vaccine against E. coli O157:H7
ABSTRACT
Objectives: CtxB [Cholera toxin B subunit] contributes to a vaccine's efficacy by stimulating production of the anti-CtxB antibody. Various attempts have been made to increase production of this antibody. Chitosan is a mucoadhesive polysaccharide that has tremendous potential for oral vaccine delivery in terms of its exclusive features that include biocompatibility, biodegradability, high charge density and non-toxicity. We investigated the potential for chitosan nanofibers and nanocapsules as novel carrier systems for the oral delivery of CtxB
Methods: Antigen-containing chitosan nanofibers were prepared by electrospinning a chitosan/AcOH solution. Encapsulation of the antigen inside the chitosan nanofibers was confirmed through infrared spectroscopy analysis [FTIR]. Guinea pigs were immunized with free antigen and CtxB antigen or antigen alone by direct administration of antigencontaining chitosan nanofibers into the buccal cavity. Serum immunoglobulin G [IgG] and intestinal immunoglobulin A [IgA] antibody responses were determined
Results: The results indicated that antigen in the chitosan nanofibers or nanocapsules elicited very high IgA and IgG responses. No detectable IgA and IgG responses were obtained after oral immunization with CtxB. The results of the antibody titer were analyzed using the ANOVA and LSD tests
Conclusion: CtxB inside the nanofiber increased antibody production when administered orally. This system might be used for delivery of other antigens
ABSTRACT
Curcumin as a yellow natural compound extracted from turmeric root is known it as an antibacterial agent. One of the nanoparticles ability is to decrease the defects of usual drug delivery systems. Chitosan is a low toxic, biodegradable, biocompatible and safe polymer which is used in production of nanoparticles. Nanoparticles like chitosan-tripolyphosphate [TPP] are able to increase antibacterial properties of curcumin. Curcumin-loaded chitosan-TPP nanoparticles containing chitosan, curcumin and TPP salt were synthesized by ionotropic gelation methods. First, the skin of anesthetized mice was inoculated with staphylococcus aureus and pseudomonas aeruginosa suspension. Then the infected mice were treated with curcumin-loaded chitosan-TPP nanoparticles for 3 days. Following that, antibacterial characteristics of the mice treated with curcumin-loaded chitosan- TPP nanoparticles were evaluated by bacterial culture of these mice. Our results showed the size of 160 +/- 10 nm and the charge of +7 +/- 2 mV in curcumin-loaded chitosan-TPP nanoparticles. These nanoparticles were also spiral shape. The encapsulation efficiency of curcumin in chitosan-TPP nanoparticles was 75 +/- 2%. Bacterial culture showed that curcumin-loaded chitosan-TPP nanoparticles inhibited staphylococcus aureus and pseudomonas aeruginosa growth. Our study demonstrated that curcumin-loaded chitosan-TPP nanoparticles can be utilized as a potent agent in treatment of Staphylococcus aureus and Pseudomonas aeruginosa infections