Development of nanoparticle adjuvants to potentiate the immune response against diphtheria toxoid.

BACKGROUND: Over the years, diphtheria was known as contagious fatal infection caused by Corynebacterium diphtheria that affects upper respiratory system. The spread of diphtheria epidemic disease is best prevented by vaccination with diphtheria toxoid vaccine. Aluminum adjuvants were reported to stimulate the immune responses to killed and subunit vaccines. OBJECTIVE: Our study aimed to minimize adjuvant particles size, to gain insight of resulting immunity titer and impact on immune response antibody subtypes. METHODS: Aluminum salts and calcium phosphate adjuvants were prepared, followed by micro/nanoparticle adjuvants preparation. After formulation of diphtheria vaccine from diphtheria toxoid and developed adjuvants, we evaluated efficacy of these prepared vaccines based on their impact on immune response via measuring antibodies titer, antibodies isotyping and cytokines profile in immunized mice. RESULTS: A noteworthy increase in immunological parameters was observed; antibodies titer was higher in serum of mice injected with nanoparticle adjuvants-containing vaccine than mice injected with standard adjuvant-containing vaccine and commercial vaccine. Aluminum compounds adjuvants (nanoparticles and microparticles formulation) and microparticles calcium phosphate adjuvant induce TH2 response, while nanoparticles calcium phosphate and microparticles aluminum compounds adjuvants stimulate TH1 response. CONCLUSIONS: Different treatments to our adjuvant preparations (nanoparticles and microparticles formulation) had a considerable impact on vaccine immunogenicity.

Adjuvants for Clostridium tetani and Clostridium diphtheriae vaccines updating.

It's known that diphtheria and tetanus are a contagious lethal diseases over the years, they caused by pathogenic microbes corynebacterium diphtheria and Clostridium tetani, respectively. The diseases result from the production of bacterial toxin. Vaccination with bacterial toxoid vaccines adsorbed on particulates adjuvants still are the best way to prevent this epidemic diseases from spread. The particulate vaccines have been shown to be more efficient than soluble one for the induction of the immune responses. Nanoparticles can be engineered to enhance the immune responses. As well known the immune response to inactivate killed and subunit vaccine enhances by alum adjuvants. The adjuvants examined and tested after reducing its size to particle size, thus mimic size of viruses which is considered smallest units can derive the immune system. The major issue is minimizing the adjuvant particles, to gain insight of resulting immunity types and impact on immune response. The adjuvant effect of micro/nanoparticles appears to largely be a consequence of their uptake into antigen presenting cells.