Fetal Calf Serum Exerts an Inhibitory Effect on Replication of Duck Hepatitis A Virus Genotype 1 in Duck Embryo Fibroblast Cells

Abstract

Among the causative agents of duck viral hepatitis, duck hepatitis A virus genotype 1 (DHAV-1) is the most common virus reported in most outbreaks worldwide. How to propagate DHAV-1 in cell cultures efficiently remains a problem to be explored. Here, we aimed to test the effect of serum type on DHAV-1 replication in duck embryo fibroblast (DEF) cells. Comparative studies involved virus culture and passage, observation of cytopathic effect (CPE), virus quantification, and plaque formation assay. From the results of these investigations, we conclude that use of chicken serum (CS) in maintenance medium allows DHAV-1 to establish productive, cytocidal infection in DEF cells, whereas FCS exerts inhibitory effects on DHAV-1 replication, CPE development, and plaque formation. By using a neutralization test, we found that the direct action of FCS on virions is likely to play a key role in inhibiting DHAV-1 replication in DEF cells. Mechanism analyses revealed that FCS inhibits DHAV-1 replication at virus adsorption and reduces extracellular virus yields. The present work may shed light on a new perspective for antiviral agent development, and have provided a virus–host cell system for further studies on molecular mechanism involved DHAV-1 replication and pathogenesis.

Integrated miRNA and mRNA Expression Profiles Reveal Differentially Expressed miR-222a as an Antiviral Factor Against Duck Hepatitis A Virus Type 1 Infection

“…DEFs were infected with the LY0801 strain (3 multiple of infection (MOI)) and incubated for 2 h at 37°C. The cells were cultivated in DMEM supplemented with 2% chicken serum for 12–48 h post infection (hpi) ( Wang et al., 2020 ). Three-day-old SPF ducks were intramuscularly injected with DHAV-1.…”

“…DHAV is classified into three serogroups based on their genetic sequences: DHAV-1, DHAV-2, and DHAV-3 ( Gao et al., 2012 ). Among the causative agents of DVH, DHAV-1 is the most prevalent and is distributed worldwide ( Wang et al., 2020 ). As a fatal, rapidly spreading virus, DHAV-1 transmits through the digestive and respiratory tracts via breathing and direct contact, leading to a mortality rate of 90% in ducklings within three weeks ( Wen et al., 2018 ).…”

Long Noncoding RNA Expression Rofiles Elucidate the Potential Roles of lncRNA- XR_003496198 in Duck Hepatitis A Virus Type 1 Infection

“…FCS (fetal calf serum) nonspecifically inhibits DHAV-1, whereas CS exerted no or minimal inhibitory influence (Chalmers and Woolcock, 1984). Therefore, according to a previous report, we tried to culture DHAV-1 in a maintenance medium with 2% CS (Wang et al, 2020). To identify DHAV-1's replication efficiency in DEFs, we established the growth kinetics curve of the virulent LY0801 strain.…”