Bonafe, C. F. | bioRxiv Science

bioRxiv2018

Porcine Parvovirus VP1/VP2 on a Time Series Epitope Mapping: exploring the effects of high hydrostatic pressure on the immune recognition of antigens.

Porcine parvovirus (PPV) is a DNA virus that causes reproductive failure in gilts and sows, resulting in embryonic and fetal losses worldwide. Epitope mapping of PPV is important for developing new vaccines. In this study, we used spot synthesis analysis for epitope mapping of the capsid proteins of PPV (NADL-2 strain) and correlated the findings with predictive data from immunoinformatics. The virus was exposed to three conditions prior to inoculation in pigs: native (untreated), high hydrostatic pressure (350 MPa for 1 h) at room temperature and high hydrostatic pressure (350 MPa for 1h) at -18 {degrees}C, compared with a commercial vaccine produced using inactivated PPV. The screening of serum samples detected 44 positive spots corresponding to 20 antigenic sites. Each type of inoculated antigen elicited a distinct epitope set. In silico prediction located linear and discontinuous epitopes in B cells that coincided with several epitopes detected in spot synthesis of sera from pigs that received different preparations of inoculum. The approach used here provided important information on the antibody/antigen interactions required to improve B cell responses to PPV and may be useful in developing novel strategies for producing new vaccines.\n\nAbbreviations3D, three dimensional; HHP, high hydrostatic pressure; ID, identification; IEDB, Immune Epitope Database; ORFs, open reading frames; p.i., post-infection; PPV, porcine parvovirus; RMSD, root-mean-square deviation of atomic positions; R(g), radius of gyration. RMSF, root-mean-square fluctuation; SK6, Swine kidney cell; SPF, specific pathogen free; TCID50/mL, Median Tissue Culture Infectious Dose; HI, Hemagglutination Inhibition.

microbiology↗

bioRxiv2018

Molecular dynamics suggests antiviral compounds active against Dengue Virus show similar binding patterns to Zika Virus proteins

The Zika virus (ZIKV) arrival in Brazilian territory brought to light the need for preparedness regarding arboviruses in Brazil. Compound screening is a cumbersome process dependent upon in vitro testing and validation. Recently, virtual screening methods have improved precision and reliability providing a framework for in silico testing of lead compound candidates. Here we have applied these methods on compounds that were previously shown to be active against Dengue virus in vitro, taking the structural information of such compounds and applying docking methods to identify putative binding sites. A molecular dynamics approach was also used to refine the docking results. The computational experiments ran here suggests that compounds such as Epigallocatechin Gallate, Ergotamine and Avermectin-B1a bind to active sites on the viral enzymes NS5 and NS3, as well as on its Envelope protein. Refinement shows that such bindings were not lost during the production run and key regions on both enzymes were structurally displaced on average over the simulation time. Interestingly there is no documented drug interactions among these candidates, raising the possibility of drug combinations during treatments. Moreover, the candidate compounds have been extensively studied, thus providing important information regarding intracellular interactions caused by them, which are also associated with pathways exploited by the virus, suggesting possible side interactions hindering the replication process.

microbiology↗