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Inactivation of human cytomegalovirus by sodium periodate oxidation
F Geoffroy1, G Ogier, J Chantepie
1Laboratoire d'Immunochimie INSERM-C.J.F. 89-05, Faculté de Médecine Lyon-Sud, Oullins, France.
Abstract:
Human cytomegalovirus (HCMV), oxidized by sodium periodate (NaIO4), is incapable of giving rise to viral progeny in cell culture. At a NaIO4 concentration as low as 5 mM, there is a loss of at least 6 logs of viral infectivity which occurs very rapidly (less than 5 min). Further, the inactivation is a first-order reaction depending on the periodate concentration. Adsorption to the cell surface, penetration into cells, and penetration of the viral DNA into cell nuclei were found to occur identically in mock oxidized and oxidized HCMV. Since the carbohydrate moiety of viral glycoproteins was the target of periodate attack, these observations strongly suggest that the structural integrity of the sugar residues is not a prerequisite for adsorption and penetration. Nevertheless, no evidence for viral DNA or protein synthesis was detected in cells infected with oxidized virus, and even after 3 weeks in culture, no cytopathic effect was observed.
Insights
Oxidizing human cytomegalovirus (HCMV) with sodium periodate rapidly inactivates the virus. While HCMV can still attach to and enter cells, it cannot replicate or cause infection, indicating sugar residue integrity is not essential for initial viral entry.
Area of Science:
- Virology
- Biochemistry
Background:
- Human cytomegalovirus (HCMV) is a significant human pathogen.
- Viral glycoproteins contain carbohydrate moieties crucial for viral function.
Purpose of the Study:
- To investigate the effect of sodium periodate (NaIO4) oxidation on HCMV infectivity.
- To determine the role of carbohydrate moieties in viral adsorption and penetration.
Main Methods:
- HCMV was oxidized using varying concentrations of NaIO4.
- Viral infectivity was measured by plaque assays.
- Viral adsorption, penetration, and DNA/protein synthesis were assessed in cell culture.
Main Results:
- NaIO4 rapidly inactivated HCMV, reducing infectivity by at least 6 logs within 5 minutes.
- Oxidation followed first-order kinetics with respect to periodate concentration.
- Oxidized HCMV adsorbed to cells, penetrated them, and delivered its DNA to the nucleus similarly to untreated virus.
- No viral DNA or protein synthesis was detected, and no cytopathic effect was observed in infected cells.
Conclusions:
- The carbohydrate moiety of HCMV glycoproteins is essential for viral replication, not for initial cell entry.
- Oxidation of sugar residues by NaIO4 effectively inactivates HCMV without preventing adsorption and penetration.