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Horn, E.

Publications and source records attributed to Horn, E..

3 recordsLinked to original sources

Impact of modification of envelope proteins on the mechanical properties of HIV virus-like particles

The mechanical interactions between virus-like particles and host cells may offer targets for new viral treatments and vaccines with modes of action that are independent of the immune system. The physical properties of structures involved govern the particle-cell interactions. While the mechanical properties of virions and mammalian cells have been widely studied, data on virus-like particles are limited. This study aimed to determine the mechanical and morphological properties of HIV-1 virus-like particles with different envelopes. Three HIV-like particles, i.e. GagM + gp150, GagM + gp140HA2tr, and GagM + gp120HA2, were produced by combining the same Gag protein shell with different trimeric glycoprotein envelopes. The particles spring constant, breaking force, and dimensions were determined using atomic force microscopy, and the elastic modulus was quantified using finite element analysis. Spring constant, elastic modulus, and breaking force were higher for GagM + gp140HA2tr and GagM + gp120HA2 than for GagM + gp150. The particle height was smaller for GagM + gp120HA2 than for GagM + gp150 and GagM + gp140HA2tr. Possible mechanisms underlying the increase of the particles stiffness and mechanical strength are the inclusion of the influenza virus HA transmembrane domain in the HIV Env protein, and the lower expression and packing density of Env in GagM + gp140HA2tr and GagM + gp120HA2 compared to GagM + gp150 found previously. Upon confirmation, the proposed mechanisms offer potential to tailor the mechanics of HIV virus-like particles and guide mechanical interactions between VLPs and host cells towards improving vaccines.

biophysics↗

Red knots in Europe - a dead end host species or a new niche for highly pathogenic avian influenza?

The 2020/2021 epidemic in Europe of highly pathogenic avian influenza virus (HPAIV) of subtype H5 surpassed all previously recorded European outbreaks in size, genotype constellations and reassortment frequency and continued into 2022 and 2023. The causative 2.3.4.4b viral lineage proved to be highly proficient with respect to reassortment with cocirculating low pathogenic AIV and seems to establish an endemic status in northern Europe. A specific HPAIV reassortant of the subtype H5N3 was detected almost exclusively in red knots (Calidris canutus islandica) in December 2020. It caused systemic and rapidly fatal disease leading to a singular and self-limiting mass mortality affecting about 3.500 birds in the German Wadden Sea, roughly 1% of the entire flyway population of islandica red knots. Phylogenetic analyses revealed that the H5N3 reassortant very likely had formed in red knots and remained confined to this species. While mechanisms of virus circulation in potential reservoir species, dynamics of spill-over and reassortment events and the roles of environmental virus sources remain to be identified, the year-round infection pressure poses severe threats to endangered avian species, and prompts adaptation of habitat and species conservation practices. One-Sentence SummaryHigh red knot mortality in Europe (December 2020) was associated with infection of a unique genotype of HPAIV H5N3 clade 2.3.4.4b.

ecology↗

Rise of the Cybercrabs: how digital cloning in an integrated taxonomic framework can support deep-sea exploration

Taxonomy has been a labour-intensive field of expertise based on hours of manual work and lengthy comments that are mainly bound to books and publications on a two-dimensional world. But every species described is a three-dimensional organism that needs to be seen, manipulated to be fully understood in its native shape. Nowadays, digital technology allows us to transform everyone in an avatar or a digital clone with ease, but collections do not provide many type specimens in a digital format. Here we present a simple approach used to study a specific deep-sea crab Segonzacia mesatlantica and provide online digital taxonomy across four repository sites. This offers the possibility to describe, exchange digitally and analyse specimens in its full 3D, establish their taxonomy and share them widely on online databases as well as physically by additive manufacturing to duplicate them in collections and outreach activities. Using an integrated taxonomic approach that included the use of 3D type specimens and molecular barcoding we provide evidence that the genus Segonzacia may be more diverse than previously understood

zoology↗