Ranaviruses Bind Cells from Different Species through Interaction with Heparan Sulfate

Ranaviruses are known to infect multiple species, yet the specific proteins mediating their attachment to host cells remain unclear. While cross-species transmission has been observed, the molecular mechanisms underlying this process have not been fully elucidated. Previous studies have identified heparan sulfate as a receptor in other viral infections, but its role in ranaviruses has not been confirmed. No prior work had resolved whether ranaviruses use heparan sulfate for cell entry. This gap motivated researchers to investigate the interaction between ranaviruses and host cell receptors. The study aimed to determine if heparan sulfate is a binding factor for ranaviruses. Prior research has shown that heparan sulfate is involved in viral attachment in other systems. However, the specific role in ranaviruses remained uncertain. This study sought to bridge that knowledge gap by examining two ranaviruses and two cell lines.

The study aimed to identify the viral proteins and host cell receptors involved in ranavirus infection. Specifically, the researchers wanted to determine whether heparan sulfate is a key receptor for ranaviruses. They focused on two ranaviruses, ADRV and RGV, and two cell lines, GSTC and EPC cells. The goal was to test if heparan sulfate is necessary for viral binding and infection. The researchers hypothesized that heparan sulfate may mediate ranavirus attachment to host cells. They also wanted to assess if recombinant viral envelope proteins interact with heparin. The study sought to clarify the initial interaction between ranaviruses and host cells. By identifying this interaction, the researchers hoped to better understand ranavirus host range and transmission.

The study used two ranaviruses, ADRV and RGV, and two cell lines, GSTC and EPC cells. The researchers tested the effect of heparin on viral plaque formation in these cells. They used a concentration of 5 μg/mL heparin to assess inhibition of viral infection. Additionally, they employed heparinase I to enzymatically remove heparan sulfate from cell surfaces. The effect of this removal on plaque formation was measured. The researchers also tested whether recombinant viral proteins could bind heparin-Sepharose beads. This binding assay aimed to confirm the interaction between viral proteins and heparin. The study combined virological assays with biochemical binding experiments. The methods focused on identifying the role of heparan sulfate in ranavirus infection.

Heparin at 5 μg/mL inhibited plaque formation of both ADRV and RGV by over 80% in GSTC and EPC cells. Enzymatic removal of heparan sulfate with heparinase I significantly reduced plaque formation by both viruses. This reduction suggests that heparan sulfate is involved in ranavirus cell binding. Competition with heparin also decreased virus-cell binding, supporting the role of heparan sulfate. Recombinant viral envelope proteins ADRV-58L and RGV-53R bound to heparin-Sepharose beads. This binding implies that these proteins may interact with heparan sulfate on host cells. The results indicate that heparan sulfate is a binding factor for ranaviruses. These findings suggest that heparan sulfate is involved in the initial interaction between ranaviruses and host cells.

The study concludes that heparan sulfate is involved in the binding and infection of ADRV and RGV. The results suggest that heparan sulfate is a key receptor for ranaviruses in the cell lines tested. The inhibition of plaque formation by heparin and heparinase I supports this conclusion. The binding of recombinant viral proteins to heparin-Sepharose beads further supports this interaction. The authors propose that heparan sulfate may mediate the initial attachment of ranaviruses to host cells. This is the first report identifying heparan sulfate as a ranavirus binding factor. The findings contribute to understanding ranavirus-host interactions. The study provides evidence that heparan sulfate is a potential target for antiviral strategies.