Antigenicity, immunogenicity and passive protection induced by immunization of mice with baculovirus-expressed VP7 protein from rhesus rotavirus

Abstract

The major neutralization antigen VP7 of rhesus rotavirus (RRV) was expressed in a baculovirus recombinant system. The expressed VP7 showed the same molecular mass as native VP7, and was recognized by hyperimmune sera as well as neutralizing and non-neutralizing monoclonal antibodies (MAbs) raised against RRV. Intraperitoneal administration of the expressed VP7 in mice elicited the production of serum antibodies which were able to immunoprecipitate VP7 from RRV-infected cell lysates and to neutralize the virus in vitro. Sera from immunized mice competed for binding to RRV in an ELISA with both neutralizing and non-neutralizing MAbs specific for VP7. Using a passive protection model of rotavirus disease, vaccination of mice with the recombinant VP7 induced partial protection from infection. These results suggest that the baculovirusexpressed VP7 may be useful in priming a protective immune response to rotavirus infection.

Elisas for Rotavirus Diagnosis, Typing, and Analysis of Antibody Response

“…An RVA ELISA to measure the humoral immune response to RRV VP7 was developed by coating plates with the recombinant baculovirus-expressed VP7, followed by incubation with paired serum samples from mice immunized with recombinant VP7 (Fiore et al, 1995). The recombinant VP7 was not immunoprecipitated by Mabs that recognize antigenic region 7-1, which are the most potent RVA neutralizing antibodies (Ruggeri & Greenberg, 1991).…”

Cloning of Rota Virus Outer Capsid Protein (VP7) Gene into the pGEM Vector

“…Moreover, VP4 has been shown to be a determinant of several important functions, such as cell attachment, entry to cells, hemagglutination, and neutralization (3,6,9,10). Epitopic-specific antibodies to VP4 and VP7 correlate with protecting from infection; however, there is conflicting arguments about the role these antibodies in protection (1,3,6,8,10). Rotaviruses are causative agents of diarrheal diseases in a wide variety of mammalian animals.…”

“…Nevertheless, host susceptibility and immunity to severe rotavirus-induced diarrhea are not fully understood. The role of homotypic and heterotypic immune responses in protection against disease is still controversial despite its relevance to vaccine development (3,7,8). Introduction of rotavirus vaccines into childhood immunization programs can contribute to substantial reduction in mortality from rotavirus gastroenteritis (12,14).…”

“…Rotaviruses are causative agents of diarrheal diseases in a wide variety of mammalian animals. In humans the group A rotaviruses are associated with endemic diarrhea in children under the age of 5 year (8,13,14). Because of the significant burden of rotavirus disease among children and animals worldwide, considerable efforts have been devoted towards the development of vaccines for disease prevention and control (8,9,12).…”

“…The mature rotavirion is an icosahedron consisting of three concentric shells of protein that surround a genome of eleven segments of double-stranded RNA (ds-RNA). This genome codes for six structural proteins (VPI-VP4, VP6 and VP7) and six nonstructural proteins (NSPI-NSP6) (6,8,10). VP4 is an unglycosylated protein and forms dimeric spikes which in combination with VP7 constitute outer layer of viral capsid protein.…”