Enhanced immune response induced by BSA loaded in hydroxyethylstarch microparticles

Area of Science:

• Biomaterials Science
• Immunology
• Vaccine Development

Background:

• Microparticles and nanoparticles are advanced carriers for in vivo delivery of peptides, proteins, and DNA.
• Hydroxyethylstarch (HES) microparticles offer potential for improved antigen release and presentation to antigen-presenting cells.

Purpose of the Study:

• To investigate the adjuvant activity of novel HES microparticles as a vaccine carrier.
• To evaluate the immune response induced by HES microparticles using bovine serum albumin (BSA) as a model antigen in mice.

Main Methods:

• Fabrication of HES microparticles via interfacial cross-linking with terephtaloyl chloride.
• Immunization of mice with BSA-HES microparticles.
• Analysis of phagocytosis by peritoneal mononuclear cells.
• Assessment of antibody synthesis (immunoglobulin G1 and IgG).
• Cytokine profiling (interferon-gamma and interleukin-4) of spleen cells.

Main Results:

• HES microparticles were effectively phagocytosed by mononuclear cells.
• Immunization with BSA-HES microparticles induced predominantly immunoglobulin G1 (IgG1) antibody synthesis.
• Aluminium hydroxide was more effective in inducing overall IgG synthesis.
• BSA-HES microparticles stimulated the secretion of both interferon-gamma (IFN-γ) and interleukin-4 (IL-4), indicating a mixed Th1/Th2 response.
• The route of injection influenced the immune response.

Conclusions:

• HES microparticles serve as a viable delivery and presentation system for antigens.
• HES microparticles induce a balanced T helper 1/T helper 2 immune response against BSA.
• These findings support the potential of HES microparticles in vaccine development, although route of administration is a key factor.