Ricin toxin B subunit enhancement of rotavirus NSP4 immunogenicity in mice.
A 90-amino acid peptide from the simian rotavirus SA-11 nonstructural protein, NSP4 was linked to the N-terminus of the Ricinus communis A-B toxin B subunit protein (RTB) and synthesized in Escherichia coli. Recombinant RTB and the NSP4(90)::RTB fusion protein bound artificial receptor glycoprotein asialofetuin in an in vitro enzyme-linked immunosorbent assay (ELISA), demonstrating biological activity of the recombinant protein. Mice co-inoculated with purified recombinant RTB plus NSP4(90) peptide proteins or heat denatured NSP4(90)::RTB fusion protein generated higher titers of serum anti-NSP4(90) IgG antibodies than mice immunized with NSP4(90) peptide alone, indicating the presence of adjuvant functions for N-terminal linked RTB. Serum anti-NSP4(90) IgG titers were highest in mice immunized with native recombinant NSP4(90)::RTB fusion protein, confirming the immunostimulatory function of RTB. Results of experiments described here demonstrate the feasibility of using RTB mediated adjuvant functions for stimulation of the antigenicity of a rotavirus nonstructural protein. The ability of recombinant NSP4(90)::RTB fusion protein synthesized in E. coli to bind glycoprotein receptor molecules effectively indicates that protein linkage to the RTB N-terminus and synthesis of the recombinant NSP4(90)::RTB fusion protein in bacteria do not interfere with the immunostimulatory properties of the RTB subunit.
Choi
Nak-Won
NW
Center for Molecular Biology and Gene Therapy, Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, Califronia 92354, USA.
Estes
Mary K
MK
Langridge
William H R
WH
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins; D012276:Ricin / Q000276:immunology*; D012401:Rotavirus / Q000276:immunology*; D014118:Toxins, Biological / Q000276:immunology*; D017361:Viral Nonstructural Proteins / Q000276:immunology*
D000914:Antibodies, Viral; D006023:Glycoproteins; C081369:NS28 protein, rotavirus; D011994:Recombinant Proteins; D014118:Toxins, Biological; D017361:Viral Nonstructural Proteins; D012276:Ricin