Early apoptosis-related changes triggered by HSV-1 in individual neuronlike cells.
Early events of apoptosis following HSV-1 infection were investigated at the single-cell level using intensified fluorescence digital-imaging microscopy. The results provide evidence that infection of differentiated ND7 neuronlike cells by HSV-1 triggers detectable alterations indicative of physiological changes associated with the early stages of apoptosis. Less than 1 h after infection with HSV-1 (KOS strain) or K26GFP (GFP being fused to HSV-1 capsid protein VP26) we observed (i) moderate decrease in mitochondrial membrane potential (about 20%), (ii) exposure of phosphatidyl serine, (iii) morphological change in the mitochondria that became spherical instead of filamentous, and (iv) activation of caspase-8. Within 3 h changes reverted to normal, which indicated that apoptosis was counteracted very early following HSV-1 infection. Similar results were obtained with KOS-TK27GFP, lacking TK and UL24 proteins, suggesting that TK and UL24 play no role in apoptosis. In Vero cells mitochondrial changes characteristic of the apoptotic process were not observed following HSV-1 infection. The UV-inactivated K26GFP had the capacity to induce apoptosis in neuronlike cells. This real-time multiparametric analysis, in combination with relevant viral mutants, could be a useful approach for dissecting the roles of various viral genes in modulating apoptotic pathways during infection.
Gautier
Isabelle
I
Institut Jacques Monod, UMR 7592, CNRS, Universités P6/P7, 2, place Jussieu, 75251 Paris 05, France.
Coppey
Jacques
J
Durieux
Christiane
C
D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D036022:Capsid Proteins; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000473:pathology / Q000821:virology; D002522:Chlorocebus aethiops; D015967:Gene Expression Regulation, Viral / Q000235:genetics; D006561:Herpes Simplex / Q000378:metabolism* / Q000503:physiopathology; D018259:Herpesvirus 1, Human / Q000378:metabolism* / Q000472:pathogenicity; D008564:Membrane Potentials / Q000276:immunology; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology / Q000821:virology; D009154:Mutation / Q000235:genetics; D009420:Nervous System / Q000378:metabolism / Q000503:physiopathology / Q000821:virology*; D009474:Neurons / Q000378:metabolism / Q000821:virology*; D010718:Phosphatidylserines / Q000378:metabolism; D011930:Reaction Time / Q000502:physiology; D011993:Recombinant Fusion Proteins; D014709:Vero Cells
D036022:Capsid Proteins; D010718:Phosphatidylserines; D011993:Recombinant Fusion Proteins; C077409:capsid protein VP26, herpes simplex virus type 1; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases