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.
Center for Molecular Biology and Gene Therapy, Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, Califronia 92354, USA.
Nak-Won
NW
Choi
Mary K
MK
Estes
William H R
WH
Langridge
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