Gava, D. | Search bioRxiv

bioRxiv2023

Antigenic and genetic diversity of H1 and H3 influenza A viruses in swine in Brazil

BackgroundInfluenza A virus (IAV) circulates within human and swine populations, and pigs are considered intermediate hosts for the generation of IAV with pandemic potential. Surveillance and characterization of IAVs circulating in pig populations are crucial to strain match vaccines to control IAV transmission in pigs and quantify pandemic potential to humans. MethodsHere, we characterized the genetic and antigenic diversity of IAVs circulating in Brazilian swine between 2010-2018. Phylogenetic maximum-likelihood trees were generated for 84 Brazilian hemagglutinin (HA) gene segments. Hemagglutination inhibition (HI) assay data was used with antigenic cartography to quantify the antigenic differences among representative H1 and H3 swine viruses and relative cross-reactivity between these viruses and human seasonal vaccine strains. ResultsWe identified two genetic lineages of H1 viruses derived from separate human-to-swine transmission events (H1 1B lineage, clades 1B.2.3 and 1B.2.4), an H3 lineage that has diversified into two genetic clades (H3 1990.5.1 and 1990.5.2), and HA genes associated with the 2009 H1N1 pandemic. There was limited cross-reactivity between circulating swine lineages and significant antigenic variation within lineage. ConclusionsThe antigenic diversity among endemic IAV in swine indicates a need for regional strain-specific vaccination strategies in Brazil. Our data supports the need for systematic genomic surveillance and characterization in Brazil to improve the efficacy of swine vaccines and quantify the pandemic potential of endemic swine influenza A viruses.

microbiology↗

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↗