REVIEW | doi:10.20944/preprints202107.0320.v1
Subject: Life Sciences, Biochemistry Keywords: Cell-cell fusion; henipavirus; pathogenesis; paramyxovirus; syncytium; within-host dynamics
Online: 14 July 2021 (11:09:08 CEST)
Syncytium formation, i.e., cell-cell fusion resulting in the formation of multinucleated cells, is a hallmark of infection by paramyxoviruses and other important viruses. This natural mechanism has historically been a diagnostic marker for paramyxovirus infection in vivo and is now widely studied for virus-induced membrane fusion in vitro. However, the role of syncytium formation in within-host dissemination and pathogenicity of viruses remains poorly understood. The diversity of henipaviruses and their wide host range and tissue tropism make them particularly appropriate models to characterize the drivers of syncytium formation and its implications for virus fitness and pathogenicity. Based on the henipavirus literature, we summarized current knowledge on the mechanisms driving syncytium formation, mostly acquired from in vitro studies, and on the in vivo distribution of syncytia. While these data suggest that syncytium formation widely occurs across henipaviruses, hosts and tissues, we identified important data gaps that undermined our understanding of the role of syncytium formation in virus pathogenesis. Based on these observations, we propose solutions of varying complexity to fill these data gaps, from better practices in data archiving and publication for in vivo studies, to experimental approaches in vitro.
ARTICLE | doi:10.20944/preprints202102.0246.v1
Subject: Life Sciences, Biochemistry Keywords: Newcastle disease virus; Paramyxovirus; vaccine quality; vaccine stability; heat stability
Online: 10 February 2021 (08:23:38 CET)
Vaccination against Newcastle disease (ND), a devastating viral disease of chicken, is often hampered by thermal inactivation of the live vaccines, in particular in tropical and hot climate conditions. In the past “thermostable” vaccine strains (I-2) have been proposed to overcome this problem. In the current study, we compared the thermal stability of 6 commercially available ND vaccines. Subjected to 37°C as lyophilized preparation, two vaccines containing I-2 strains were more sensitive to inactivation than a third I-2 vaccine or when compared to three other vaccines based on different strains. However, after reconstitution strains proved to have a comparable tenacity. Interestingly, all vaccines retained a sufficient virus dose for protection (106 EID50) after 1 day at 37°C, still. However, experiments exposing ND-vaccines to elevated temperatures of 51°C and 61°C, clearly demonstrated inactivation of all dissolved vaccines within 2 to 4 hours. The data indicate preparation that specific factors may influence thermal stability rather than strain specific characteristics. Regardless of the ND strain used, the appropriate cold chain is mandatory for live ND-vaccines.