Compatibility and stability of a Shigella polysaccharide-protein conjugate antigen formulated with aluminum-salt and CpG 1018® adjuvants (Dataset)
Dotson, Brandy Chalke, Giriraj Joshi, Sangeeta B.
Dotson, Brandy
Chalke, Giriraj
Joshi, Sangeeta B.
Abstract
This study evaluated the formulation and stability of a quadrivalent glycoconjugate Shigella vaccine candidate based on four predominant strains (S. flexneri; 2a, 3a, and 6, and S. sonnei) accounting for direct global coverage of 64% of all Shigella infections. Each glycoconjugate antigen consists of a Shigella strain-specific O-polysaccharide (O-PS) covalently linked to the carrier protein IpaB, a membrane protein component of the Shigella type III secretion system. First, selective competitive ELISAs were developed to measure antigenicity of the four O-PS-IpaB conjugates formulated with aluminum-salt adjuvants (Alhydrogel®, AH and Adju-phos®, AP) and a second adjuvant CpG-1018®, CpG. Next, we focused on the monovalent S. sonnei O-PS-IpaB conjugate to elucidate antigen-alum adjuvant interactions under different solution conditions. Third, the stability profiles of AH- or AP- adjuvanted S. sonnei O-PS-IpaB conjugate antigen in various formulations (± CpG) were determined at different temperatures. Interestingly, incubation at 25 °C for 2 weeks resulted in increased antigenicity values when the antigen was bound to either AP or AH, suggesting increased epitope exposure when interacting with the adjuvant surface. When bound to AP adjuvant at pH 5.8, the best glycoconjugate antigen stability was observed at elevated temperatures. The CpG adjuvant under these conditions, however, was incompatible with loss of material observed, presumably from precipitation due to lack of interaction with AP and presence of the detergent LDAO from the bulk antigen buffer. In contrast, the glycoconjugate antigen and the CpG adjuvant were both bound to the AH adjuvant and were stable at 2-8 °C, pH 7.0. This AH-CpG formulation of the O-PS-IpaB conjugate antigens was identified as a promising candidate for future animal immunogenicity testing.
Description
This dataset accompanies the article, Compatibility and stability of a Shigella polysaccharide-protein conjugate antigen formulated with aluminum-salt and CpG 1018® adjuvants, currently in press.
Date
2025-09-04
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VeriXiv
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Keywords
Shigella vaccine, Polysaccharide-protein conjugate vaccine, Compatibility, Stability, Formulation, Adjuvant, Aluminum-salt, CpG 1018, ELISA