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Updated: Oct 24, 2026
Rescue of Recombinant Newcastle Disease Virus from cDNA
Published on: October 11, 2013
Viral factors required for interferon induction by Newcastle disease virus in mouse macrophages and chicken embryo
Abstract:
The triggering mechanism for interferon synthesis in mouse peritoneal macrophages and chick embryo (CE) cells by Newcastle disease virus (NDV) exposed to hydroxylamine or homologous antiserum was investigated in relation to the intracellular fate of these agents. Inactivation of NDV at 22 degrees C by I M-hydroxylamine proceeded with first-order kinetics, whereas the interferon-inducing capacity of hydroxylamine-treated virus in macrophages was unimpaired. In contrast to infective NDV, hydroxylamine-inactivated virus produced interferon in CE cells, and such a virus still had partial RNA-dependent RNA polymerase activity. Hydroxylamine-inactivated NDV was adsorbed to and uncoated in both normal and chloroquine diphosphate treated cells, but no viral double-stranded RNA was detected. Hydroxylamine treatment of virion-extracted RNA and neutralization of intact virions by antibody abolished the capacity of the virus to induce interferon. Infective as well as neutralized NDV interacted with macrophages to the same degree, but association between NDV and CE cells was prevented by antibody-coating. In macrophages, the RNA of neutralized NDV became more sensitive to RNase than RNA of infective NDV, but this process was inhibited in chloroquine diphosphate-treated cells. These results suggest that interferon induction by NDV involves components of the virion which are present up to the regular uncoating process.
Insights
Newcastle disease virus (NDV) inactivation by hydroxylamine does not prevent interferon induction in macrophages, suggesting viral components before uncoating trigger this immune response. However, antibody neutralization abolishes interferon production in chick embryo cells.
Area of Science:
- Virology
- Immunology
- Molecular Biology
Background:
- Newcastle disease virus (NDV) is a significant pathogen that can induce interferon synthesis.
- The precise mechanism by which NDV triggers interferon production remains incompletely understood.
Purpose of the Study:
- To investigate the triggering mechanism for interferon synthesis by NDV in mouse peritoneal macrophages and chick embryo cells.
- To elucidate the role of viral components and intracellular fate in NDV-induced interferon production.
Main Methods:
- NDV was inactivated using hydroxylamine or homologous antiserum.
- Interferon induction capacity was assessed in macrophages and chick embryo cells.
- Viral adsorption, uncoating, RNA-dependent RNA polymerase activity, and RNase sensitivity were analyzed.
Main Results:
- Hydroxylamine-inactivated NDV retained interferon-inducing capacity in macrophages and partially in chick embryo cells, with some RNA-dependent RNA polymerase activity.
- Hydroxylamine-inactivated NDV adsorbed and uncoated in cells, but viral double-stranded RNA was not detected.
- Antibody neutralization abolished interferon induction capacity in chick embryo cells and altered RNA sensitivity to RNase in macrophages.
Conclusions:
- Interferon induction by NDV involves viral components present up to the uncoating stage.
- The cell type influences the mechanism of interferon induction by NDV.
- Viral RNA integrity and specific viral components are crucial for triggering interferon synthesis.
