학술논문

Crystalline and Amorphous Preparation of Aluminum Hydroxide Nanoparticles Enhances Protective Antigen Domain 4 Specific Immunogenicity and Provides Protection Against Anthrax
ORIGINAL RESEARCH
Document Type
Academic Journal
Source
International Journal of Nanomedicine. January 2020, Vol. 15, p239, 13 p.
Subject
India
Language
English
ISSN
1178-2013
Abstract
Introduction Anthrax, a zoonotic disease, is caused by the etiological agent Bacillus anthracis, which is Gram-positive, rod-shaped and spore-forming. The virulence of B. anthracis is encoded by two plasmids, namely, [...]
Introduction: Aluminum salts, although they have been used as adjuvants in many vaccine formulations since 1926, exclusively induce a Th2-biased immune response, thereby limiting their use against intracellular pathogens like Mycobacterium tuberculosis. Methods and Results: Herein, we synthesized amorphous and crystalline forms of aluminum hydroxide nanoparticles (AH nps) of 150-200 nm size range. Using Bacillus anthracis protective antigen domain 4 (D4) as a model antigen, we demonstrated that both amorphous and crystalline forms of AH nps displayed enhanced antigen D4 uptake by THP1 cells as compared to commercial adjuvant aluminum hydroxide gel (AH gel). In a mouse model, both amorphous and crystalline AH nps triggered an enhanced D4-specific Th2- and Th1-type immune response and conferred superior protection against anthrax spore challenge as compared to AH gel. Physicochemical characterization of crystalline and amorphous AH nps revealed stronger antigen D4 binding and release than AH gel. Conclusion: These results demonstrate that size and crystallinity of AH nps play important roles in mediating enhanced antigen presenting cells (APCs) activation and potentiating a strong antigen-specific immune response, and are critical parameters for the rational design of alum-based Th1-type adjuvant to induce a more balanced antigen-specific immune response. Keywords: aluminum hydroxide gel, crystalline nanoparticles, NLRP3 inflammasome, Th1/Th2 immune response, amorphous nanoparticles