Infectious bursal disease virus (IBDV) causes a highly immunosuppressive disease in chickens. Currently available, live IBDV vaccines can lead to generation of variant viruses. We have developed an alternative vaccine that will not create variant IBDV. By using the reverse genetics approach, we devised a recombinant Newcastle disease virus (NDV) vector from a commonly used vaccine strain LaSota to express the hostprotective immunogen VP2 of a variant IBDV strain GLS-5. The gene encoding the VP2 protein of the IBDV was inserted into the most 3-proximal locus of a full-length NDV cDNA for high-level expression. We successfully recovered the recombinant virus, rLaSota/VP2. The rLaSota/VP2 was genetically stable, at least up to 12 serial passages in chicken embryos, and was shown to express the VP2 protein. The VP2 protein was not incorporated into the virions of recombinant virus. Recombinant rLaSota/VP2 replicated to a titer similar to that of parental NDV strain LaSota in chicken embryos and cell cultures. To assess protective efficacy of the rLaSota/VP2, 2-day-old specific-pathogen-free chickens were vaccinated with the recombinant virus and challenged with a highly virulent NDV strain Texas GB or IBDV variant strain GLS-5 at 3 weeks postvaccination. Vaccination with rLaSota/VP2 generated antibody responses against both NDV and IBDV and provided 90% protection against NDV and IBDV. Booster immunization induced higher levels of antibody responses against both NDV and IBDV and conferred complete protection against both viruses. These results indicate that the recombinant NDV can be used as a vaccine vector for other avian pathogens.Infectious bursal disease virus (IBDV) is a pathogen of major economic importance in the poultry industry worldwide. IBDV replicates specifically in developing B-lymphoid cells, resulting in the destruction of the precursors of antibody-producing B cells in the bursa of Fabricius, and consequently, the immunosuppression, which leads to vaccination failures and susceptibility to other infections and diseases (25). Vaccination is the principal method used for the control of infectious bursal disease in chickens. Although IBDV strains of different antigenic types have been incorporated into vaccines, IBDV remains a major problem for the poultry industry. The efficacy of current live IBDV vaccines decreases in the presence of maternal antibodies, which are essential for the protection of young chickens for the critical first few weeks of life. Live IBDV vaccines also cause various degrees of bursal atrophy and may contribute to the emergence of antigenic variant viruses (25). The first antigenic variant strain of IBDV was isolated from vaccinated flocks on the Delmarva Peninsula in 1985 (40). Other variant strains were subsequently isolated in the United States and other countries (17,35,41,42,46). The antigenic variant strains were serologically different from the so-called classic isolates most typically isolated before 1985 (25,42,46). These variant strains lack the epitope(s) defined by...
3-O-(3',3'-dimethylsuccinyl) betulinic acid, also termed PA-457 or DSB, is a novel HIV-1 inhibitor that blocks virus maturation by disrupting cleavage of the capsid precursor, CA-SP1. To better define the molecular target for PA-457, we prepared a panel of mutant viruses with point deletions spanning the CA-SP1 cleavage domain and characterized each of these viruses for PA-457 sensitivity. Our results indicate that amino acid residues in the N-terminal half of SP1 serve as determinants of PA-457 activity, while residues in the C-terminal half of SP1 were not involved in compound activity. These findings support and extend previous observations that PA-457 is a specific inhibitor of CA-SP1 cleavage and identify the CA-SP1 domain as the primary viral determinant for this novel inhibitor of HIV-1 replication.
The interaction of bovine respiratory syncytial virus (BRSV) phosphoprotein (P) with nucleocapsid (N) and large polymerase (L) proteins was investigated using an intracellular BRSV-CAT minigenome replication system. Coimmunoprecipitation assays using P-specific antiserum revealed that the P protein can form complexes with N and L proteins. Deletion mutant analysis of the P protein was performed to identify the regions of P protein that interact with N and L proteins. The results indicate that two independent N-binding sites exist on the P protein : an internal region of 161-180 amino acids and a C-terminal region of 221-241 amino acids. The L-binding site was mapped to a region of P protein encompassing amino acids 121-160. The data suggest that N and L protein binding domains on the P protein do not overlap.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.