A partially purified outer membrane protein VirB9-1 for low-cost nanovaccines against Anaplasma marginale. Issue 1 (3rd January 2017)

• Record Type: Journal Article
• Authors: Zhao, Liang; Cavallaro, Antonino S.; Wibowo, David; Zhang, Bing; Zhang, Jun; Mitter, Neena; Yu, Chengzhong; Zhao, Chun-Xia; Middelberg, Anton P.J.
• Is Part Of: Vaccine. Volume 35:Issue 1(2017)
• Page Start: 77
• Page End: 83
• Publication Date: 2017-01-03
• Subjects: Anaplasma marginale -- Partially-purified antigens -- Aggregates -- Endotoxin -- Silica vesicles -- Immunogenicity; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2016.11.037
• Languages: English
• ISSNs: 0264-410X

Abstract

Abstract: Anaplasma marginale is a devastating tick-borne pathogen causing anaplasmosis in cattle and results in significant economic loss to the cattle industry worldwide. Currently, there is no widely accepted vaccine against A. marginale . New generation subunit vaccines against A. marginale, which are much safer, more efficient and cost-effective, are in great need. The A. marginale outer membrane protein VirB9-1 is a promising antigen for vaccination. We previously have shown that soluble recombinant VirB9-1 protein can be expressed and purified from Escherichia coli and induce a high level of humoral and cellular immunity in mice. In this study, we re-formulated the nanovaccines using the partially-purified VirB9-1 protein as the antigen and hollow nano-size silica vesicles (SV-100) as the adjuvant. We simplified the purification method to obtain the partially-purified antigen VirB9-1 with a six-fold higher yield. The new formulations using the partially-purified VirB9-1 protein achieved higher antibody and cell-mediated immune responses compared to the purified ones. This finding suggests that the partially-purified VirB9-1 protein performs better than the purified ones in the vaccination against A. marginale, and a certain level of contaminants in the protein antigen can be self-adjuvant and boost immunogenicity together with the nanoparticle adjuvant. This may lead to finding a "Goldilocks" level of contaminants. The new nanovaccine formulation using partially-purified antigens along with nanoparticle adjuvants offers an alternative strategy for making cheaper veterinary vaccines.