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Effect of chromium and manganese particles on the interferon system
Abstract:
Mammalian (LLC-MK2) cell monolayers pretreated with either chromium or manganese particles depressed viral induction of IFN by approximately 50% but the presence of metal particles did not prevent exogenous IFN from conferring antiviral cellular resistance. Manganese particles were more detrimental to viral IFN induction than chromium particles in that almost tenfold less of the former achieved a comparable magnitude of IFN inhibition. Although rates of influenza virus multiplication in either chromium or manganese-treated and control cell cultures were similar, virus attained a level of growth almost twofold higher in metal-treated cells than in controls. This was related to suppression of viral IFN induction by metal particles. Neuraminidase treatment of cell surface salioglycoproteins or pretreatment of chromium or manganese particles with sialic acid abrogated the adverse activity of metal particles on viral IFN induction. These findings suggest that the receptivity and interaction of cell membrane-bound sialic acid residues with metal particles are involved in the altered cellular protective response described.
Insights
Metal particles like chromium and manganese inhibit viral interferon (IFN) induction in mammalian cells. This suppression enhances viral growth, suggesting sialic acid interactions are key to this altered cellular response.
Area of Science:
- Virology
- Cell Biology
- Immunology
Background:
- Interferon (IFN) is a crucial cytokine for antiviral defense.
- Mammalian cells utilize IFN induction to establish antiviral states.
- Metal particles can interact with cellular components, potentially affecting biological responses.
Purpose of the Study:
- To investigate the impact of chromium and manganese particles on viral interferon induction in LLC-MK2 cells.
- To determine if metal particle pretreatment affects the efficacy of exogenous interferon.
- To elucidate the mechanism by which metal particles influence viral replication and interferon production.
Main Methods:
- LLC-MK2 cell monolayers were pretreated with chromium or manganese particles.
- Viral induction of interferon was measured.
- Exogenous interferon's antiviral activity was assessed.
- Influenza virus multiplication rates were quantified.
- Neuraminidase treatment and sialic acid pretreatment were employed to probe mechanisms.
Main Results:
- Chromium and manganese particles significantly depressed viral interferon induction by ~50%.
- Manganese particles were more potent inhibitors of interferon induction than chromium particles.
- Metal particle pretreatment did not impede exogenous interferon's antiviral effects.
- Virus replication was twofold higher in metal-treated cells due to suppressed interferon induction.
- Neuraminidase treatment or sialic acid pretreatment abrogated the inhibitory effects of metal particles on interferon induction.
Conclusions:
- Cell membrane-bound sialic acid residues play a critical role in the interaction with metal particles.
- Metal particle interaction with sialic acid residues alters the cellular protective response to viral infections.
- Suppression of viral interferon induction by metal particles contributes to increased viral replication.