Chitosan Plus Compound 48/80: Formulation and Preliminary Evaluation as a Hepatitis B Vaccine Adjuvant.

Current vaccine research is mostly based on subunit antigens. Despite the better toxicity profile of these antigens they are often poorly immunogenic, so adjuvant association has been explored as a strategy to obtain a potent vaccine formulation. Recently, mast cell activators were recognized as a new class of vaccine adjuvants capable of potentiating mucosal and systemic immune responses.

IL-33 Is a Negative Regulator of Vaccine-Induced Antigen-Specific Cellular Immunity.

The cytokine IL-33 is a well-established inducer of Th2 responses. However, roles for IL-33 in promoting CD8, Th1, and T regulatory cell responses have also emerged. In this study, the role of IL-33 as a regulator of particulate vaccine adjuvant-induced Ag-specific cellular immunity was investigated.

Effect of particulate adjuvant on the anthrax protective antigen dose required for effective nasal vaccination.

Successful vaccine development is dependent on the development of effective adjuvants since the poor immunogenicity of modern subunit vaccines typically requires the use of potent adjuvants and high antigen doses. In recent years, adjuvant formulations combining both immunopotentiators and delivery systems have emerged as a promising strategy to develop effective and improved vaccines. In this study we investigate if the association of the mast cell activating adjuvant compound 48/80 (C48/80) with chitosan nanoparticles would promote an antigen dose sparing effect when administered intranasally.

Validation of a new 96-well plate spectrophotometric method for the quantification of compound 48/80 associated with particles.

A new, simple, inexpensive, and rapid 96-well plate UV spectrophotometric method was developed and validated for the quantification of compound 48/80 (C48/80) associated with particles. C48/80 was quantified at 570 nm after reaction with acetaldehyde and sodium nitroprusside in an alkaline solution (pH 9.6).

Chitosan-based nanoparticles as a hepatitis B antigen delivery system.

The design of antigen delivery systems, particularly for mucosal surfaces, has been a focus of interest in recent years. In this chapter, we describe the preparation of chitosan-based particles as promising antigen delivery systems for mucosal surfaces already tested by our group with hepatitis B surface antigen. The final proof of the concept is always carried out with immunization studies performed in an appropriate animal model.

Mucosal vaccines: recent progress in understanding the natural barriers.

It has long been known that protection against pathogens invading the organism via mucosal surfaces correlates better with the presence of specific antibodies in local secretions than with serum antibodies. The most effective way to induce mucosal immunity is to administer antigens directly to the mucosal surface. The development of vaccines for mucosal application requires antigen delivery systems and immunopotentiators that efficiently facilitate the presentation of the antigen to the mucosal immune system.