ABSTRACT
DNA vaccination using a plasmid encoding the rotavirus inner capsid VP6 has been explored in the mouse model of rotavirus infection. BALB/c mice were immunized with a VP6 DNA vaccine by the intramuscular, nasal and oral routes. VP6 DNA vaccination by the nasal and oral routes induced the production of anti-VP6 IgA antibodies by intestinal lymphoid cells. Intramuscular DNA injection stimulated the production of serum anti-VP6 IgG but not serum anti-VP6 IgA antibodies. Protection against shedding of rotaviruses in stools after oral challenge with the murine EDIM rotavirus strain was investigated in the immunized mice. A significant reduction in the level of rotavirus antigen shedding was demonstrated in those mice immunized at mucosal surfaces, both orally and nasally, with the VP6 DNA vaccine. Intramuscular DNA immunization, which elicited serum anti-VP6 IgG responses but not virus-specific intestinal IgA antibodies, did not provide significant protection against rotavirus challenge.
Subject(s)
Antigens, Viral/immunology , Capsid Proteins/immunology , Rotavirus Infections/prevention & control , Rotavirus Vaccines/administration & dosage , Vaccines, DNA/immunology , Administration, Intranasal , Administration, Oral , Animals , Antibodies, Viral/analysis , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Feces/chemistry , Feces/virology , Female , Immunoglobulin A/analysis , Immunoglobulin G/blood , Injections, Intramuscular , Mice , Mice, Inbred BALB C , Rotavirus Vaccines/immunology , Vaccines, DNA/administration & dosage , Vaccines, Synthetic , Virus Shedding/immunologyABSTRACT
The rotavirus nonstructural NSP4 protein, a transmembrane endoplasmic reticulum-specific glycoprotein, has been described as the first viral enterotoxin. Purified NSP4 or a peptide corresponding to NSP4 residues 114-135 induces diarrhea in young mice. NSP4 has a membrane-destabilizing activity and causes an increase in intracellular calcium levels and chloride secretion by a calcium-dependent signalling pathway in eucaryotic cells. In this study, four recombinant baculoviruses were generated expressing the rotavirus NSP4 glycoprotein from the human strains Wa and Ito, the porcine strain OSU, and the simian strain SA11, which belong to two different NSP4 genotypes, A and B. The recombinant glycoproteins, expressed as polyhistidine-tagged molecules, were analyzed by Western blotting and immunoprecipitation. Newborn mice responded with diarrhea after inoculation with each of the recombinant NSP4 proteins.
