title: Isolation and characterization of herpes simplex virus type 1 resistant to aminothiazolylphenyl-based inhibitors of the viral helicase-primase.
abstract: The aminothiazolylphenyl-containing compounds BILS 179 BS and BILS 45 BS are novel inhibitors of the herpes simplex virus helicase-primase with antiviral activity in vitro and in animal models of HSV disease. To verify the mechanism of antiviral action, resistant viruses were selected by serial passage or by single-step plaque selection of HSV-1 KOS in the presence of inhibitors. Three resistant isolates K138r3, K22r5, and K22r1 were found to be 38-, 316-, and 2500-fold resistant to BILS 22 BS, a potent analog of BILS 45 BS. All three viruses had growth properties in vitro similar to wild-type HSV-1 KOS but they were sensitive to acyclovir. Cutaneous and intra-cerebral inoculation of mice with K22r1 or K22r5 resulted in pathogenicity equivalent to that of HSV-1 KOS. Both isolates were fully competent for reactivation from latency following corneal inoculation. Helicase-primase purified from cells infected with resistant viruses showed decreased inhibition in an in vitro DNA-dependent ATPase assay that correlated well with antiviral resistance. Marker transfer experiments and DNA sequence analysis identified single base pair mutations clustered in the N-terminus of the UL5 gene that resulted in single amino acid changes in the UL5 protein. Taken together, the results indicate that helicase-primase inhibitors prevent HSV growth by inhibiting HSV helicase-primase through specific interaction with the UL5 protein.
authors.affiliation: Boehringer Ingelheim (Canada) Ltd., Research and Development, 2100 Cunard Street, Laval, Que., H7S 2G5, Canada. mliuzzi@lav.boehringer-ingelheim.ca
authors.forename: Michel
authors.initials: M
authors.lastname: Liuzzi
authors.forename: Philip
authors.initials: P
authors.lastname: Kibler
authors.forename: Christiane
authors.initials: C
authors.lastname: Bousquet
authors.forename: Fayaz
authors.initials: F
authors.lastname: Harji
authors.forename: Gordon
authors.initials: G
authors.lastname: Bolger
authors.forename: Michel
authors.initials: M
authors.lastname: Garneau
authors.forename: Nicole
authors.initials: N
authors.lastname: Lapeyre
authors.forename: Robert S
authors.initials: RS
authors.lastname: McCollum
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Faucher
authors.forename: Bruno
authors.initials: B
authors.lastname: Simoneau
authors.forename: Michael G
authors.initials: MG
authors.lastname: Cordingley
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D004265:DNA Helicases / Q000037:antagonists & inhibitors*; D019915:DNA Primase; D004195:Disease Models, Animal; D024882:Drug Resistance, Viral; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D018259:Herpesvirus 1, Human / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D051379:Mice; D008807:Mice, Inbred BALB C; D016296:Mutagenesis; D013844:Thiazoles / Q000737:chemistry* / Q000494:pharmacology; D014764:Viral Proteins
chemical_list: D000998:Antiviral Agents; D004791:Enzyme Inhibitors; D013844:Thiazoles; D014764:Viral Proteins; C004483:2-aminothiazole; D019915:DNA Primase; C062021:helicase-primase, Human herpesvirus 1; D004265:DNA Helicases