IADR Abstract Archives
Effect of Epstein Barr Virus on Host Intereferon Signalling Pathways
Objectives: 1. To investigate whether Epstein Barr Virus (EBV) affects Interferon signalling pathways (IFN-SP) during primary infection.
2. To identify potential EBV proteins responsible for manipulating IFN-SP.
3. To observe effect of interferon on EBV infectivity and pathogenesis
Methods: Luciferase promoter assay was used to observe the effect of EBV and its latent and lytic proteins on IFN-SP. Luciferase gene is under control of a promoter whose activity can be measured as light output using Luminometer. The activity of IFN-SP downstream promoter was measured and the results were confirmed by quantifying mRNA levels of IFN-SP-downstream genes using quantitative-PCR. Effect of interferon on EBV infection was studied by treating HEKi293 cells with interferon, prior to EBV infection. Since EBV is tagged with green fluorescent protein (GFP), the infectivity was proportional to number of GFP-positive cells, observed under confocal microscope. The results were confirmed by flow-cytometry analysis of GFP-positive cells. All results were reproducible for n=3 trials.
Results: 1. EBV inhibited both interferon production and signalling pathways during primary infection.
2. Major EBV proteins-Zta, Rta were found to be potent inhibitors of IFN-SP.
3. EBV infectivity was decreased when cells were treated with interferon prior to infection. But when above mentioned proteins were overexpressed in the system before interferon treatment, infectivity was enhanced. This showed that these proteins might help EBV to escape host immune responses.
Conclusions: By altering interferon production and signalling, EBV can escape host immune responses to facilitate its pathogenesis. Targeting IFN-SP components might provide possible therapeutic therapy for EBV-related diseases.
2. To identify potential EBV proteins responsible for manipulating IFN-SP.
3. To observe effect of interferon on EBV infectivity and pathogenesis
Methods: Luciferase promoter assay was used to observe the effect of EBV and its latent and lytic proteins on IFN-SP. Luciferase gene is under control of a promoter whose activity can be measured as light output using Luminometer. The activity of IFN-SP downstream promoter was measured and the results were confirmed by quantifying mRNA levels of IFN-SP-downstream genes using quantitative-PCR. Effect of interferon on EBV infection was studied by treating HEKi293 cells with interferon, prior to EBV infection. Since EBV is tagged with green fluorescent protein (GFP), the infectivity was proportional to number of GFP-positive cells, observed under confocal microscope. The results were confirmed by flow-cytometry analysis of GFP-positive cells. All results were reproducible for n=3 trials.
Results: 1. EBV inhibited both interferon production and signalling pathways during primary infection.
2. Major EBV proteins-Zta, Rta were found to be potent inhibitors of IFN-SP.
3. EBV infectivity was decreased when cells were treated with interferon prior to infection. But when above mentioned proteins were overexpressed in the system before interferon treatment, infectivity was enhanced. This showed that these proteins might help EBV to escape host immune responses.
Conclusions: By altering interferon production and signalling, EBV can escape host immune responses to facilitate its pathogenesis. Targeting IFN-SP components might provide possible therapeutic therapy for EBV-related diseases.