This study examined how Newcastle disease virus (NDV) infection affects the susceptibility of mammalian cells to agglutination by plant lectins. Researchers infected chick embryo and baby hamster kidney cells with various NDV strains and tested their ability to bind concanavalin A (Con A) and wheat germ agglutinin (WGA). Virulent and mesogenic NDV strains (HERTS, WARWICK, TEXAS, FIELD PHEASANT, LAMB ESSEX, BEAUDETTE C) rendered infected cells susceptible to lectin-mediated agglutination, correlating with observable reductions in cell coat thickness. In contrast, avirulent NDV strains (QUEENSLAND, ULSTER) did not produce these changes. The agglutination response required viral protein synthesis within the first three hours of infection and could be inhibited by specific lectin inhibitors, confirming specificity. Purified virus particles from virulent strains were also agglutinated by lectins, indicating that cell surface lectin-receptor sites were incorporated into the viral envelope during budding. These findings demonstrate that NDV-induced alterations to the cell coat material expose or redistribute lectin-binding sites on infected cells and viral particles.

Key findings

• Infection with virulent NDV strains renders normally non-agglutinatable cells susceptible to agglutination by Con A and WGA lectins
• Cell coat thickness reduction correlates temporally with increased lectin-mediated agglutination of infected cells
• Avirulent NDV strains produce no changes in cell coat or lectin susceptibility despite equivalent viral replication
• Virus-induced protein synthesis within three hours of infection is essential for altered agglutination behavior
• Purified virions from virulent NDV strains are agglutinated by lectins, indicating incorporation of host cell lectin-receptors into the viral envelope