Influenza Virus Segment Composition Influences Viral Stability in the Environment

Abstract

The transmission routes of Influenza A viruses (IAVs) submit virus particles to a wide range of environmental conditions that affect their transmission. In water, temperature, salinity, and pH are important factors modulating viral persistence in a strain-dependent manner, and the viral factors driving IAV persistence remain to be described. We used an innovative method based on a real-time cell system analysis to quantify viral decay in an environmental model. Thus, we identified the viral hemagglutinin (HA) and neuraminidase (NA) as the main proteins driving the environmental persistence by comparing the inactivation slopes of several reassortant viruses. We also introduced synonymous and non-synonymous mutations in the HA or in the NA that modulated IAV persistence. Our results demonstrate that HA stability and expression level, as well as calcium-binding sites of the NA protein, are molecular determinants of viral persistence. Finally, IAV particles could not trigger membrane fusion after environmental exposure, stressing the importance of the HA and the NA for environmental persistence.

Immune Escape Adaptive Mutations in the H7N9 Avian Influenza Hemagglutinin Protein Increase Virus Replication Fitness and Decrease Pandemic Potential

“…Of note, we identified that A151T substitution in HA also resulted in a dramatic decrease in HA thermal stability while not affecting its acid stability. The weak thermal stability has been linked to poor environmental presence and might not benefit virus transmission (46). This finding might explain the poor transmission of HPAI H7N1 with glycosylation at amino acid 149 between turkeys and chickens (43).…”

HA stabilization promotes replication and transmission of swine H1N1 gamma influenza viruses in ferrets

“…Multiple mechanisms may be operational. HA proteins with a lower activation pH have increased resistance to extracellular inactivation and have increased environmental stability ( Poulson et al, 2016 ; Labadie et al, 2018 ; Russier et al, 2020 ). This may be important because the human upper respiratory tract is mildly acidic ( England et al, 1999 ; Man et al, 2017 ).…”

Historical Discoveries on Viruses in the Environment and Their Impact on Public Health

“…The presence of sludge in water may also provide a protective effect, with the clay adsorbing polio virus particles and protecting them against ultraviolet radiations [70], although it has a negative effect on the rotavirus resistance to heat treatments [71]. In addition to environmental factors, viral factors are also determinants for virion stability in the environment, such as the presence of mutations in the structural proteins [80,81], or the lipid composition for enveloped viruses [82]. The study of these factors affecting virus persistence contributed greatly to the development of virus control methods and public health in the population, which are summarized in the grey circle.…”

“…Similarly, Nishisaka-Nonaka et al [122] suggested that UV inactivates the influenza virus by preventing the viral replication without altering the function of the external viral proteins. Interestingly, our previous results showed that after virus inactivation in an aquatic environment, the virus remained able to attach to its cellular receptor, but cannot enter into the cell [80], and presented an unaltered genome [82,123]. A new visible-light-induced photocatalyst has also been reported for its virucidal effect on influenza virus, allowing degradation of 99% of viral particles in <30 min with a very weak light source [124].…”

“…sentiweb.fr) [151], and climate data originate from the MeteoNet dataset (Meteo France) [152]. DOI: 10.1159/000511575 ers of the environmental persistence of the virus [80,[153][154][155]. This could potentially explain how different strains of influenza virus or strains from different origins can have different persistence in the environment [82,156].…”