The L1 protein of human papilloma virus 16 expressed by a fowlpox virus recombinant can assemble into virus-like particles in mammalian cell lines but elicits a non-neutralising humoral response

Construction and immune protection evaluation of recombinant virus expressing Newcastle disease virus F protein by the largest intergenic region of fowlpox virus NX10

Fowlpox virus (FPV) is used as a vaccine vector to prevent diseases in poultry and mammals. The insertion site is considered as one of the main factors influencing foreign gene expression. Therefore, the identification of insertion sites that can stably and efficiently express foreign genes is crucial for the construction of recombinant vaccines. In this study, we found that the insertion of foreign genes into ORF054 and the ORF161/ORF162 intergenic region of the FPV genome did not affect replication, and that the foreign genes inserted into the intergenic region were more efficiently expressed than when they were inserted into a gene. Based on these results, the recombinant virus rFPVNX10-NDV F-E was constructed and immune protection against virulent FPV and Newcastle disease virus (NDV) was evaluated. Tests for anti-FPV antibodies in the vaccinated chickens were positive within 14 days post-vaccination. After challenge with FPV102, no clinical signs of FP were observed in vaccinated chickens, as compared to that in the control group (unvaccinated), which showed 100% morbidity. Low levels of NDV-specific neutralizing antibodies were detected in vaccinated chickens before challenge. After challenge with NDV ck/CH/LHLJ/01/06, all control chickens died within 4 days post-challenge, whereas 5/15 vaccinated chickens died between 4 and 12 days post-challenge. Vaccination provided an immune protection rate of 66.7%, whereas the control group showed 100% mortality. These results indicate that the ORF161/ORF162 intergenic region of FPVNX10 can be used as a recombination site for foreign gene expression in vivo and in vitro.

Benzamide Derivatives Targeting the Cell Division Protein FtsZ: Modifications of the Linker and the Benzodioxane Scaffold and Their Effects on Antimicrobial Activity

Filamentous temperature-sensitive Z (FtsZ) is a prokaryotic protein with an essential role in the bacterial cell division process. It is widely conserved and expressed in both Gram-positive and Gram-negative strains. In the last decade, several research groups have pointed out molecules able to target FtsZ in Staphylococcus aureus, Bacillus subtilis and other Gram-positive strains, with sub-micromolar Minimum Inhibitory Concentrations (MICs). Conversely, no promising derivatives active on Gram-negatives have been found up to now. Here, we report our results on a class of benzamide compounds, which showed comparable inhibitory activities on both S. aureus and Escherichia coli FtsZ, even though they proved to be substrates of E. coli efflux pump AcrAB, thus affecting the antimicrobial activity. These surprising results confirmed how a single molecule can target both species while maintaining potent antimicrobial activity. A further computational study helped us decipher the structural features necessary for broad spectrum activity and assess the drug-like profile and the on-target activity of this family of compounds.

Benzodioxane-Benzamides as Antibacterial Agents: Computational and SAR Studies to Evaluate the Influence of the 7-Substitution in FtsZ Interaction

FtsZ is a crucial prokaryotic protein involved in bacterial cell replication. It recently arose as a promising target in the search for antimicrobial agents able to fight antimicrobial resistance. In this work, going on with our structure-activity relationship (SAR) study, we developed variously 7-substituted 1,4-benzodioxane compounds, linked to the 2,6-difluorobenzamide by a methylenoxy bridge. Compounds exhibit promising antibacterial activities not only against multidrug-resistant Staphylococcus aureus, but also on mutated Escherichia coli strains, thus enlarging their spectrum of action toward Gram-negative bacteria as well. Computational studies elucidated, through a validated FtsZ binding protocol, the structural features of new promising derivatives as FtsZ inhibitors.

3-(Benzodioxan-2-ylmethoxy)-2,6-difluorobenzamides bearing hydrophobic substituents at the 7-position of the benzodioxane nucleus potently inhibit methicillin-resistant Sa and Mtb cell division

Lipophilic substituents at benzodioxane C (7) of 3-(benzodioxan-2-ylmethoxy)-2,6-difluorobenzamide improve the antibacterial activity against methicillin-resistant Staphylococcus aureus strains to MIC values in the range of 0.2-2.5 μg/mL, whereas hydrophilic substituents at the same position and modifications at the benzodioxane substructure, excepting for replacement with 2-cromanyl, are deleterious. Some of the lead compounds also exhibit good activity against Mtb. Parallel SARs to those of 3-(2-benzothiazol-2-ylmethoxy)-2,6-difluorobenzamide, well known FtsZ inhibitor, and cells alterations typical of FtsZ inhibition indicate such a protein as the target of these potent antibacterial benzodioxane-benzamides.