Rotavirus subunit vaccines are being evaluated for use in humans. The virus-like particles (VLPs) for these vaccines are produced in insect cells coinfected with combinations of baculovirus recombinants expressing bovine RIF VP2 and simian SA11, VP4, VP6, or VP7 rotavirus proteins. VLPs were administered parenterally to mice and rabbits, and the immunogenicity and protective efficacy of the vaccines were evaluated. Rabbits vaccinated with VP2/4/6/7 or VP2/6/7 VLP combinations developed high levels of rotavirus-specific serum antibody and fecal IgG but not fecal IgA. The induction of fecal IgG was associated with total or partial protection from oral challenge with ALA rotavirus. Heterotypic serum and fecal neutralizing antibody was induced in mice vaccinated parenterally with G1 VP2/6/7 or VP2/4/6n VLPs. VLPs were highly immunogenic when administered in QS21 adjuvant, inducing serum neutralizing antibody titers comparable to those induced by SA11 virus. VLPs are effective immunogens when administered parenterally and may be an effective subunit vaccine.

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Cleavage maps of the three similar Bacillus subtilis temperate bacteriophages, 4105, plO, and p14, were constructed by partial digestion analysis utilizing the restriction endonuclease EcoRI. Comparison of the topography of these maps indicates that all phage DNAs possess cohesive ends and a number of EcoRI restriction sites; the fragments are conserved, and the estimated base substitution/nucleotide divergence between these phages is 0.03 to 0.07 based on conserved fragments or between 0.03 and 0.11 based on conserved cleavage sites. These lines of evidence indicate that 4105, plO, and p14 are closely related. Double-enzyme digestion analysis reveals that p14 DNA has unique SalGI and BglJI restriction sites and 4105 DNA has a unique SalGI restriction site, making these phages possible cloning vectors for B. subtilis.With the advent of restriction endonucleases, physical maps of various bacteriophages have been constructed: 429 (12). One use of restriction maps is in the analysis of related phage DNAs (15). Van den Hondel and Schoenmaker (24) used extensive mapping in quantitating the similarities and differences of the closely related filamentous bacteriophages M13, fd, fl, and Z J/2. More recently, Godson (5, 6) used the same technique to determine the base sequence divergence between the phages OX174, S13, and on August 4, 2020 by guest