Biophysical characterization and immunization studies of dominant negative inhibitor (DNI), a candidate anthrax toxin subunit vaccine

• Published in: Human vaccines & immunotherapeutics 2013-11, Vol.9 (11), p.2362-2370
• Main Authors: Iyer, Vidyashankara, Hu, Lei, Schanté, Carole E, Vance, David, Chadwick, Chrystal, Jain, Nishant Kumar, Brey, Robert N, Joshi, Sangeeta B, Volkin, David B, Andra, Kiran K, Bann, James G, Mantis, Nicholas J, Middaugh, C. Russell
• Format: Article
• Language: English
• Subjects: accelerated stability; Adjuvants, Immunologic - administration & dosage; aluminum hydroxide; Aluminum Hydroxide - administration & dosage; Animals; Anthrax - prevention & control; Anthrax Vaccines - administration & dosage; Anthrax Vaccines - immunology; Antigens, Bacterial - chemistry; Antigens, Bacterial - immunology; Bacillus anthracis - immunology; Bacterial Toxins - chemistry; Bacterial Toxins - immunology; biophysical characterization; Biophysical Phenomena; dominant-negative inhibitor; Drug Stability; Freeze Drying; Immunization - methods; immunogenicity; Mice, Inbred BALB C; Protein Conformation; Protein Stability - radiation effects; Protein Subunits - chemistry; Protein Subunits - immunology; Research Paper; Temperature; vaccine; Vaccines, Subunit - administration & dosage; Vaccines, Subunit - immunology
• ISSN: 2164-5515; 2164-554X
• DOI: 10.4161/hv.25852

Dominant negative inhibitor (DNI) is a translocation-deficient homolog of recombinant protective antigen of Bacillus anthracis that is a candidate for a next generation anthrax vaccine. This study demonstrates that the biophysical characteristics of the DNI protein stored in lyophilized form at 4 °C for 8 y were similar to recombinant protective antigen (rPA). To provide information on the accelerated stability of DNI, samples in the lyophilized form were subjected to thermal stress (40 and 70 °C for up to 4 weeks) and thoroughly evaluated using various biophysical and chemical characterization techniques. Results demonstrate preserved structural stability of the DNI protein under extreme conditions, suggesting long-term stability can be achieved for a vaccine that employs DNI, as desired for a biodefense countermeasure. Furthermore, the biological activity of the stressed DNI bound to the adjuvant Alhydrogel ® was evaluated in mice and it was found that the immunogenicity DNI was not affected by thermal stress.