Expression of beta-galactosidase in neurons of dorsal root ganglia which are latently infected with herpes simplex virus type 1.
Explanation into culture of dorsal root ganglia (DRG) latently infected with herpes simplex virus type 1 (HSV-1) causes reactivation of the virus. Previous studies have suggested that either latency-associated transcripts (LATs) were removed as an early consequence of reactivation or, alternatively, there was a population of latently infected cells which did not contain LATs. We have now attempted to detect this population of neurons by inserting a reporter gene (Escherichia coli lacZ gene), under the control of promoters other than LAT, into the HSV-1 strain 17 mutant in 1814, which was used in the earlier studies. One of these promoters, the human cytomegalovirus enhancer, resulted in weak expression of beta-galactosidase in DRG neurons for at least 5 months. The pattern of staining was predominantly homogeneous in neurons at 3 or 5 days post-infection or at 3 days post-explanation, and was predominantly speckled in latently infected neurons (1 to 5 months post-infection). About 30% of the beta-galactosidase-positive neurons did not contain LATs by in situ hybridization. However, the detergents used to enable penetration of the substrate for beta-galactosidase had also reduced the levels of the LATs; in neurons which originally had only small numbers of LATs this may have reduced levels to below those detectable by the methods used. There was, therefore, no unequivocal evidence for a population of latently HSV-1-infected cells which did not express LATs.
Ecob-Prince
M S
MS
University of Glasgow Department of Neurology, Southern General Hospital, UK.
Hassan
K
K
Denheen
M T
MT
Preston
C M
CM
D000818:Animals; D003587:Cytomegalovirus / Q000235:genetics; D004742:Enhancer Elements, Genetic; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005727:Ganglia, Spinal / Q000201:enzymology / Q000821:virology*; D018259:Herpesvirus 1, Human / Q000254:growth & development / Q000502:physiology*; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009474:Neurons / Q000201:enzymology / Q000821:virology*; D009924:Organ Culture Techniques; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic; D014162:Transfection; D014775:Virus Activation; D001616:beta-Galactosidase / Q000096:biosynthesis*
D001616:beta-Galactosidase