1
|
Santos Bravo M, Plault N, Sánchez-Palomino S, Rodríguez C, Navarro Gabriel M, Mosquera MM, Fernández Avilés F, Suarez-Lledó M, Rovira M, Bodro M, Moreno A, Linares L, Cofan F, Berengua C, Esteva C, Cordero E, Martin-Davila P, Aranzamendi M, Pérez Jiménez AB, Vidal E, Fernández Sabé N, Len O, Hantz S, Alain S, Marcos MÁ. Genotypic and phenotypic study of antiviral resistance mutations in refractory cytomegalovirus infection. J Infect Dis 2022; 226:1528-1536. [PMID: 35993155 DOI: 10.1093/infdis/jiac349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/18/2022] [Indexed: 11/14/2022] Open
Abstract
This study describes the genotypic and phenotypic characterisation of novel human cytomegalovirus (HCMV) genetic variants of a cohort of 94 clinically-resistant HCMV patients. Antiviral-resistant mutations were detected in the UL97, UL54 and UL56 target genes of 25/94 (26.6%) patients. The genotype-phenotype correlation study resolved the status of 5 uncharacterised UL54 DNA polymerase (G441S, A543V, F460S, R512C, A928T) and 2 UL56 terminase (F345L, P800L) mutations found in clinical isolates. A928T conferred high triple-resistance to ganciclovir, foscarnet and cidofovir, and A543V had 10-fold reduced susceptibility to cidofovir. Viral growth assays showed G441S, A543V, F345L and P800L impaired viral growth capacities compared with wild-type AD169 HCMV. 3D modelling predicted A543V and A928T phenotypes but not R512C, reinforcing the need for individual characterisation of mutations by recombinant phenotyping. Extending mutation databases is crucial to optimize treatments and to improve the assessment of patients with resistant/refractory HCMV infection.
Collapse
Affiliation(s)
- Marta Santos Bravo
- Microbiology Department, Hospital Clinic of Barcelona, University of Barcelona. Institute for Global Health (ISGlobal), Barcelona, Spain
| | - Nicolas Plault
- National Reference Center for Herpesviruses, Microbiology Department, CHU Limoges, Limoges, France.,UMR Inserm 1092, University of Limoges, Limoges, France
| | - Sonsoles Sánchez-Palomino
- AIDS Research Group, Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic I Provincial de Barcelona, University of Barcelona, Barcelona, Spain
| | - Cristina Rodríguez
- Microbiology Department, Hospital Clinic of Barcelona, University of Barcelona. Institute for Global Health (ISGlobal), Barcelona, Spain
| | - Mireia Navarro Gabriel
- Microbiology Department, Hospital Clinic of Barcelona, University of Barcelona. Institute for Global Health (ISGlobal), Barcelona, Spain
| | - María Mar Mosquera
- Microbiology Department, Hospital Clinic of Barcelona, University of Barcelona. Institute for Global Health (ISGlobal), Barcelona, Spain
| | - Francesc Fernández Avilés
- Bone Marrow Transplant Unit, Hematology Department, Clinical Institute of Hematological and Oncological Diseases (ICMHO) Hospital Clinic of Barcelona, , Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Josep Carreras Leukaemia Research Institute, Barcelona, Spain
| | - María Suarez-Lledó
- Bone Marrow Transplant Unit, Hematology Department, Clinical Institute of Hematological and Oncological Diseases (ICMHO) Hospital Clinic of Barcelona, , Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Josep Carreras Leukaemia Research Institute, Barcelona, Spain
| | - Montserrat Rovira
- Bone Marrow Transplant Unit, Hematology Department, Clinical Institute of Hematological and Oncological Diseases (ICMHO) Hospital Clinic of Barcelona, , Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Josep Carreras Leukaemia Research Institute, Barcelona, Spain
| | - Marta Bodro
- Infectious Diseases Department, Hospital Clinic of Barcelona, Barcelona, Spain
| | - Asunción Moreno
- Infectious Diseases Department, Hospital Clinic of Barcelona, Barcelona, Spain
| | - Laura Linares
- Infectious Diseases Department, Hospital Clinic of Barcelona, Barcelona, Spain
| | - Frederic Cofan
- Renal Transplantation Unit, Department of Nephrology. Hospital Clinic of Barcelona, Barcelona, Spain
| | - Carla Berengua
- Microbiology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Cristina Esteva
- Molecular Microbiology Unit, Hospital Universitari Sant Joan de Déu, Barcelona, Spain. Malalties Prevenibles amb Vacunes, Institut de Recerca Sant Joan de Déu, Universitat de Barcelona. Centre of Biomedical Research for Epidemiology and Public Health (CIBERESP), Barcelona, Spain
| | - Elisa Cordero
- Clinical Unit of Infectious Diseases, Microbiology, and Preventive Medicine. Viral and Infectious Diseases in Immunodeficient Group. Institute of Biomedicine of Seville (IBiS). Virgen del Rocio University Hospital. University of Seville. Seville, Spain
| | | | - Maitane Aranzamendi
- Microbiology Department. Hospital Universitario de Cruces, Donostia, Gipuzkoa, Spain
| | - Ana Belén Pérez Jiménez
- Microbiology Unit, Hospital Universitario Reina Sofía, Intituto Maimonides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain. Centre of Biomedical Research for Infectious Diseases (CIBERINFEC), Intitute of Carlos III, Madrid, Spain
| | - Elisa Vidal
- Microbiology Unit, Hospital Universitario Reina Sofía, Intituto Maimonides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain. Centre of Biomedical Research for Infectious Diseases (CIBERINFEC), Intitute of Carlos III, Madrid, Spain
| | - Nuria Fernández Sabé
- Department of Infectious Diseases, Bellvitge University Hospital, Insitut D'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain
| | - Oscar Len
- Department of Infectious Diseases, Hospital Universitari Vall d'Hebrón, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Sebastien Hantz
- National Reference Center for Herpesviruses, Microbiology Department, CHU Limoges, Limoges, France.,UMR Inserm 1092, University of Limoges, Limoges, France
| | - Sophie Alain
- National Reference Center for Herpesviruses, Microbiology Department, CHU Limoges, Limoges, France.,UMR Inserm 1092, University of Limoges, Limoges, France
| | - María Ángeles Marcos
- Microbiology Department, Hospital Clinic of Barcelona, University of Barcelona. Institute for Global Health (ISGlobal), Barcelona, Spain
| | | |
Collapse
|
2
|
Torii Y, Horiba K, Kawada JI, Haruta K, Yamaguchi M, Suzuki T, Uryu H, Kashiwa N, Goishi K, Ogi T, Ito Y. Detection of antiviral drug resistance in patients with congenital cytomegalovirus infection using long-read sequencing: a retrospective observational study. BMC Infect Dis 2022; 22:568. [PMID: 35733089 PMCID: PMC9219161 DOI: 10.1186/s12879-022-07537-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 06/08/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Congenital human cytomegalovirus (cCMV) infection can cause sensorineural hearing loss and neurodevelopmental disabilities in children. Ganciclovir and valganciclovir (GCV/VGCV) improve long-term audiologic and neurodevelopmental outcomes for patients with cCMV infection; however, antiviral drug resistance has been documented in some cases. Long-read sequencing can be used for the detection of drug resistance mutations. The objective of this study was to develop full-length analysis of UL97 and UL54, target genes with mutations that confer GCV/VGCV resistance using long-read sequencing, and investigate drug resistance mutation in patients with cCMV infection. METHODS Drug resistance mutation analysis was retrospectively performed in 11 patients with cCMV infection treated with GCV/VGCV. UL97 and UL54 genes were amplified using blood DNA. The amplicons were sequenced using a long-read sequencer and aligned with the reference gene. Single nucleotide variants were detected and replaced with the reference sequence. The replaced sequence was submitted to a mutation resistance analyzer, which is an open platform for drug resistance mutations. RESULTS Two drug resistance mutations (UL54 V823A and UL97 A594V) were found in one patient. Both mutations emerged after 6 months of therapy, where viral load increased. Mutation rates subsided after cessation of GCV/VGCV treatment. CONCLUSIONS Antiviral drug resistance can emerge in patients with cCMV receiving long-term therapy. Full-length analysis of UL97 and UL54 via long-read sequencing enabled the rapid and comprehensive detection of drug resistance mutations.
Collapse
Affiliation(s)
- Yuka Torii
- Department of Pediatrics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
| | - Kazuhiro Horiba
- Department of Pediatrics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan.,Department of Genetics, Research Institute of Environmental Medicine Nagoya University, Furo-cho, Chikusa-ku, 464-8601, Nagoya, Japan.,Department of Human Genetics and Molecular Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
| | - Jun-Ichi Kawada
- Department of Pediatrics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
| | - Kazunori Haruta
- Department of Pediatrics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
| | - Makoto Yamaguchi
- Department of Pediatrics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
| | - Takako Suzuki
- Department of Pediatrics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
| | - Hideko Uryu
- Department of Pediatrics, National Center for Global Health and Medicine, 1-21-1 Toyama Shinjuku-ku, Tokyo, Japan
| | - Naoyuki Kashiwa
- Department of Pediatrics, National Center for Global Health and Medicine, 1-21-1 Toyama Shinjuku-ku, Tokyo, Japan
| | - Keiji Goishi
- Department of Pediatrics, National Center for Global Health and Medicine, 1-21-1 Toyama Shinjuku-ku, Tokyo, Japan
| | - Tomoo Ogi
- Department of Genetics, Research Institute of Environmental Medicine Nagoya University, Furo-cho, Chikusa-ku, 464-8601, Nagoya, Japan.,Department of Human Genetics and Molecular Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
| | - Yoshinori Ito
- Department of Pediatrics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan. .,Department of Pediatrics and Child Health, Nihon University School of Medicine, 30-1 Oyaguchi, Kami-cho, Itabashi-ku, 173-8610, Tokyo, Japan.
| |
Collapse
|
3
|
Chaturvedi S, Pablo M, Wolf M, Rosas-Rivera D, Calia G, Kumar AJ, Vardi N, Du K, Glazier J, Ke R, Chan MF, Perelson AS, Weinberger LS. Disrupting autorepression circuitry generates "open-loop lethality" to yield escape-resistant antiviral agents. Cell 2022; 185:2086-2102.e22. [PMID: 35561685 PMCID: PMC9097017 DOI: 10.1016/j.cell.2022.04.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 03/01/2022] [Accepted: 04/14/2022] [Indexed: 12/27/2022]
Abstract
Across biological scales, gene-regulatory networks employ autorepression (negative feedback) to maintain homeostasis and minimize failure from aberrant expression. Here, we present a proof of concept that disrupting transcriptional negative feedback dysregulates viral gene expression to therapeutically inhibit replication and confers a high evolutionary barrier to resistance. We find that nucleic-acid decoys mimicking cis-regulatory sites act as "feedback disruptors," break homeostasis, and increase viral transcription factors to cytotoxic levels (termed "open-loop lethality"). Feedback disruptors against herpesviruses reduced viral replication >2-logs without activating innate immunity, showed sub-nM IC50, synergized with standard-of-care antivirals, and inhibited virus replication in mice. In contrast to approved antivirals where resistance rapidly emerged, no feedback-disruptor escape mutants evolved in long-term cultures. For SARS-CoV-2, disruption of a putative feedback circuit also generated open-loop lethality, reducing viral titers by >1-log. These results demonstrate that generating open-loop lethality, via negative-feedback disruption, may yield a class of antimicrobials with a high genetic barrier to resistance.
Collapse
Affiliation(s)
- Sonali Chaturvedi
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA.
| | - Michael Pablo
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Marie Wolf
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Daniel Rosas-Rivera
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Giuliana Calia
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Arjun J Kumar
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Noam Vardi
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Kelvin Du
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Joshua Glazier
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Ruian Ke
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Matilda F Chan
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alan S Perelson
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Leor S Weinberger
- Gladstone/UCSF Center for Cell Circuitry, Gladstone Institutes, San Francisco, CA 94158, USA; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, CA 94158, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA.
| |
Collapse
|
4
|
Abstract
Human herpesviruses are large double-stranded DNA viruses belonging to the Herpesviridae family. The main characteristics of these viruses are their ability to establish a lifelong latency into the host with a potential to reactivate periodically. Primary infections and reactivations with herpesviruses are responsible for a large spectrum of diseases and may result in severe complications in immunocompromised patients. The viral DNA polymerase is a key enzyme in the replicative cycle of herpesviruses, and the target of most antiviral agents (i.e., nucleoside, nucleotide and pyrophosphate analogs). However, long-term prophylaxis and treatment with these antivirals may lead to the emergence of drug-resistant isolates harboring mutations in genes encoding viral enzymes that phosphorylate drugs (nucleoside analogs) and/or DNA polymerases, with potential cross-resistance between the different analogs. Drug resistance mutations mainly arise in conserved regions of the polymerase and exonuclease functional domains of these enzymes. In the polymerase domain, mutations associated with resistance to nucleoside/nucleotide analogs may directly or indirectly affect drug binding or incorporation into the primer strand, or increase the rate of extension of DNA to overcome chain termination. In the exonuclease domain, mutations conferring resistance to nucleoside/nucleotide analogs may reduce the rate of excision of incorporated drug, or continue DNA elongation after drug incorporation without excision. Mutations associated with resistance to pyrophosphate analogs may alter drug binding or the conformational changes of the polymerase domain required for an efficient activity of the enzyme. Novel herpesvirus inhibitors with a potent antiviral activity against drug-resistant isolates are thus needed urgently.
Collapse
Affiliation(s)
| | - Guy Boivin
- CHU de Québec-Université Laval, Quebec City, QC, Canada.
| |
Collapse
|
5
|
Jinnouchi F, Mori Y, Yoshimoto G, Yamauchi T, Nunomura T, Yurino A, Hayashi M, Yuda J, Shima T, Odawara J, Takashima S, Kamezaki K, Kato K, Miyamoto T, Akashi K, Takenaka K. Incidence of refractory cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation. Int J Hematol 2021; 115:96-106. [PMID: 34652633 DOI: 10.1007/s12185-021-03218-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 09/06/2021] [Accepted: 09/06/2021] [Indexed: 10/20/2022]
Abstract
Post-transplant cytomegalovirus (CMV) disease can be almost completely avoided by current infection control procedures. However, CMV reactivation occurs in more than half of patients, and some patients can develop clinically resistant CMV infections. Whether resistance is due to the host's immune status or a viral resistance mutation is challenging to confirm. Therefore, a prospective observational analysis of refractory CMV infection was conducted in 199 consecutive patients who received allogeneic hematopoietic stem cell transplantation at a single institution. Among them, 143 (72%) patients received anti-CMV drugs due to CMV reactivation, and only 17 (8.5%) exhibited refractory CMV infection. These patients had clinically refractory infection. However, viral genome analysis revealed that only one patient exhibited a mutation associated with the anti-CMV drug resistance. Clinical resistance was mainly correlated with host immune factors, and the incidence of resistance caused by gene mutations was low at the early stage after a transplantation.
Collapse
Affiliation(s)
- Fumiaki Jinnouchi
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Yasuo Mori
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Goichi Yoshimoto
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Takuji Yamauchi
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Takuya Nunomura
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Ayano Yurino
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Masayasu Hayashi
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Junichiro Yuda
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Takahiro Shima
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Jun Odawara
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Shuichiro Takashima
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Kenjiro Kamezaki
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Koji Kato
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Toshihiro Miyamoto
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Koichi Akashi
- Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, 812-8582, Japan
| | - Katsuto Takenaka
- Department of Hematology, Clinical Immunology and Infectious Diseases, Ehime University Graduate School of Medicine, Toon, Ehime, 791-0295, Japan.
| |
Collapse
|
6
|
Impact of Amino Acid Substitutions in Region II and Helix K of Herpes Simplex Virus 1 and Human Cytomegalovirus DNA Polymerases on Resistance to Foscarnet. Antimicrob Agents Chemother 2021; 65:e0039021. [PMID: 33875432 DOI: 10.1128/aac.00390-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Amino acid substitutions conferring resistance of herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV) to foscarnet (PFA) are located in the genes UL30 and UL54, respectively, encoding the DNA polymerase (pol). In this study, we analyzed the impact of substitutions located in helix K and region II that are involved in the conformational changes of the DNA pol. Theoretical substitutions were identified by sequences alignment of the helix K and region II of human herpesviruses (susceptible to PFA) and bacteriophages (resistant to PFA) and introduced in viral genomes by recombinant phenotyping. We characterized the susceptibility of HSV-1 and HCMV mutants to PFA. In UL30, the substitutions I619K (helix K), V715S, and A719T (both in region II) increased mean PFA 50% effective concentrations (EC50s) by 2.5-, 5.6-, and 2.0-fold, respectively, compared to the wild type (WT). In UL54, the substitution Q579I (helix K) conferred hypersusceptibility to PFA (0.17-fold change), whereas the substitutions Q697P, V715S, and A719T (all in region II) increased mean PFA EC50s by 3.8-, 2.8- and 2.5-fold, respectively, compared to the WT. These results were confirmed by enzymatic assays using recombinant DNA pol harboring these substitutions. Three-dimensional modeling suggests that substitutions conferring resistance/hypersusceptibility to PFA located in helix K and region II of UL30 and UL54 DNA pol favor an open/closed conformation of these enzymes, resulting in a lower/higher drug affinity for the proteins. Thus, this study shows that both regions of UL30 and UL54 DNA pol are involved in the conformational changes of these proteins and can influence the susceptibility of both viruses to PFA.
Collapse
|
7
|
Chou S, Song K, Wu J, Bo T, Crumpacker C. Drug resistance mutations and associated phenotypes detected in clinical trials of maribavir for treatment of cytomegalovirus infection. J Infect Dis 2020; 226:576-584. [PMID: 32726419 PMCID: PMC9441206 DOI: 10.1093/infdis/jiaa462] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/24/2020] [Indexed: 01/26/2023] Open
Abstract
Background In separate phase 2 trials, 120 patients received maribavir for cytomegalovirus (CMV) infection failing conventional therapy (trial 202) and 119 received maribavir for asymptomatic infection (trial 203). Overall, 172 cleared their CMV infection (CMV DNA <200 copies/mL) within 6 weeks. Methods Baseline and posttreatment plasma samples were tested for mutations in viral genes UL97, UL54, and/or UL27. Selected viral mutants were phenotyped for drug susceptibility. Results Baseline samples revealed UL54 mutations newly phenotyped as conferring resistance to standard DNA polymerase inhibitor(s), including K493N, P497S, K513T, L565V, V823A, A987V, and E989D. Of 29 patients (including 25 from trial 202) who cleared but later experienced recurrent CMV infection while on maribavir, 23 had available UL97 genotyping data; 17 had known resistance mutations (T409M or H411Y) and 5 additional had UL97 C480F alone. The newly phenotyped mutation C480F conferred high-grade maribavir resistance and low-grade ganciclovir resistance. Among 25 who did not respond to >14 days of therapy, 9 showed T409M or H411Y and 4 others showed C480F alone. Conclusions After maribavir therapy (400–1200 mg twice daily), UL97 mutations T409M, H411Y, or C480F emerge to confer maribavir resistance in patients with recurrent CMV infection while on therapy or no response to therapy. Clinical Trials Registration NCT01611974 and EudraCT 2010-024247-32.
Collapse
Affiliation(s)
- Sunwen Chou
- Oregon Health & Science University and VA Health Care System, Portland OR
| | - Kening Song
- Shire Human Genetic Therapies Inc., Lexington MA, a Takeda Company
| | - Jingyang Wu
- Shire Human Genetic Therapies Inc., Lexington MA, a Takeda Company
| | - Tien Bo
- Shire Human Genetic Therapies Inc., Lexington MA, a Takeda Company
| | | |
Collapse
|
8
|
Trimpert J, Osterrieder N. Herpesvirus DNA Polymerase Mutants—How Important Is Faithful Genome Replication? CURRENT CLINICAL MICROBIOLOGY REPORTS 2019. [DOI: 10.1007/s40588-019-00135-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
9
|
Zhang L. New Insights into DNA Polymerase Function Revealed by Phosphonoacetic Acid-Sensitive T4 DNA Polymerases. Chem Res Toxicol 2017; 30:1984-1992. [PMID: 28872853 DOI: 10.1021/acs.chemrestox.7b00132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The bacteriophage T4 DNA polymerase (pol) and the closely related RB69 DNA pol have been developed into model enzymes to study family B DNA pols. While all family B DNA pols have similar structures and share conserved protein motifs, the molecular mechanism underlying natural drug resistance of nonherpes family B DNA pols and drug sensitivity of herpes DNA pols remains unknown. In the present study, we constructed T4 phages containing G466S, Y460F, G466S/Y460F, P469S, and V475W mutations in DNA pol. These amino acid substitutions replace the residues in drug-resistant T4 DNA pol with residues found in drug-sensitive herpes family DNA pols. We investigated whether the T4 phages expressing the engineered mutant DNA pols were sensitive to the antiviral drug phosphonoacetic acid (PAA) and characterized the in vivo replication fidelity of the phage DNA pols. We found that G466S substitution marginally increased PAA sensitivity, whereas Y460F substitution conferred resistance. The phage expressing a double mutant G466S/Y460F DNA pol was more PAA-sensitive. V475W T4 DNA pol was highly sensitive to PAA, as was the case with V478W RB69 DNA pol. However, DNA replication was severely compromised, which resulted in the selection of phages expressing more robust DNA pols that have strong ability to replicate DNA and contain additional amino acid substitutions that suppress PAA sensitivity. Reduced replication fidelity was observed in all mutant phages expressing PAA-sensitive DNA pols. These observations indicate that PAA sensitivity and fidelity are balanced in DNA pols that can replicate DNA in different environments.
Collapse
Affiliation(s)
- Likui Zhang
- Marine Science & Technology Institute Department of Environmental Science and Engineering, Yangzhou University , No. 196 Huayang West Road, Hanjiang, Yangzhou, Jiangsu 225127, China.,Department of Biological Sciences, University of Alberta , Edmonton, Alberta T6G 2R3, Canada
| |
Collapse
|
10
|
Zarrouk K, Piret J, Boivin G. Herpesvirus DNA polymerases: Structures, functions and inhibitors. Virus Res 2017; 234:177-192. [PMID: 28153606 DOI: 10.1016/j.virusres.2017.01.019] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/10/2017] [Accepted: 01/22/2017] [Indexed: 11/25/2022]
Abstract
Human herpesviruses are large double-stranded DNA viruses belonging to the Herpesviridae family. These viruses have the ability to establish lifelong latency into the host and to periodically reactivate. Primary infections and reactivations of herpesviruses cause a large spectrum of diseases and may lead to severe complications in immunocompromised patients. The viral DNA polymerase is a key enzyme in the lytic phase of the infection by herpesviruses. This review focuses on the structures and functions of viral DNA polymerases of herpes simplex virus (HSV) and human cytomegalovirus (HCMV). DNA polymerases of HSV (UL30) and HCMV (UL54) belong to B family DNA polymerases with which they share seven regions of homology numbered I to VII as well as a δ-region C which is homologous to DNA polymerases δ. These DNA polymerases are multi-functional enzymes exhibiting polymerase, 3'-5' exonuclease proofreading and ribonuclease H activities. Furthermore, UL30 and UL54 DNA polymerases form a complex with UL42 and UL44 processivity factors, respectively. The mechanisms involved in their polymerisation activity have been elucidated based on structural analyses of the DNA polymerase of bacteriophage RB69 crystallized under different conformations, i.e. the enzyme alone or in complex with DNA and with both DNA and incoming nucleotide. All antiviral agents currently used for the prevention or treatment of HSV and HCMV infections target the viral DNA polymerases. However, long-term administration of these antivirals may lead to the emergence of drug-resistant isolates harboring mutations in genes encoding viral enzymes that phosphorylate drugs (i.e., nucleoside analogues) and/or DNA polymerases.
Collapse
Affiliation(s)
- Karima Zarrouk
- Research Center in Infectious Diseases, CHU de Québec and Laval University, Quebec City, Quebec, Canada
| | - Jocelyne Piret
- Research Center in Infectious Diseases, CHU de Québec and Laval University, Quebec City, Quebec, Canada
| | - Guy Boivin
- Research Center in Infectious Diseases, CHU de Québec and Laval University, Quebec City, Quebec, Canada.
| |
Collapse
|
11
|
Topalis D, Gillemot S, Snoeck R, Andrei G. Distribution and effects of amino acid changes in drug-resistant α and β herpesviruses DNA polymerase. Nucleic Acids Res 2016; 44:9530-9554. [PMID: 27694307 PMCID: PMC5175367 DOI: 10.1093/nar/gkw875] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 09/13/2016] [Accepted: 09/21/2016] [Indexed: 12/15/2022] Open
Abstract
Emergence of drug-resistance to all FDA-approved antiherpesvirus agents is an increasing concern in immunocompromised patients. Herpesvirus DNA polymerase (DNApol) is currently the target of nucleos(t)ide analogue-based therapy. Mutations in DNApol that confer resistance arose in immunocompromised patients infected with herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV), and to lesser extent in herpes simplex virus 2 (HSV-2), varicella zoster virus (VZV) and human herpesvirus 6 (HHV-6). In this review, we present distinct drug-resistant mutational profiles of herpesvirus DNApol. The impact of specific DNApol amino acid changes on drug-resistance is discussed. The pattern of genetic variability related to drug-resistance differs among the herpesviruses. Two mutational profiles appeared: one favoring amino acid changes in the Palm and Finger domains of DNApol (in α-herpesviruses HSV-1, HSV-2 and VZV), and another with mutations preferentially in the 3′-5′ exonuclease domain (in β-herpesvirus HCMV and HHV-6). The mutational profile was also related to the class of compound to which drug-resistance emerged.
Collapse
Affiliation(s)
- D Topalis
- Rega Institute for Medical Research, Department Microbiology and Immunology, KU Leuven, Minderbroedersstraat 10, 3000, Leuven, Belgium
| | - S Gillemot
- Rega Institute for Medical Research, Department Microbiology and Immunology, KU Leuven, Minderbroedersstraat 10, 3000, Leuven, Belgium
| | - R Snoeck
- Rega Institute for Medical Research, Department Microbiology and Immunology, KU Leuven, Minderbroedersstraat 10, 3000, Leuven, Belgium
| | - G Andrei
- Rega Institute for Medical Research, Department Microbiology and Immunology, KU Leuven, Minderbroedersstraat 10, 3000, Leuven, Belgium
| |
Collapse
|
12
|
Abstract
Antiviral drug resistance is a matter of great clinical importance that, historically, has been investigated mostly from a virological perspective. Although the proximate mechanisms of resistance can be readily uncovered using these methods, larger evolutionary trends often remain elusive. Recent interest by population geneticists in studies of antiviral resistance has spurred new metrics for evaluating mutation and recombination rates, demographic histories of transmission and compartmentalization, and selective forces incurred during viral adaptation to antiviral drug treatment. We present up-to-date summaries on antiviral resistance for a range of drugs and viral types, and review recent advances for studying their evolutionary histories. We conclude that information imparted by demographic and selective histories, as revealed through population genomic inference, is integral to assessing the evolution of antiviral resistance as it pertains to human health.
Collapse
Affiliation(s)
- Kristen K Irwin
- School of Life Sciences, École Polytechnique Fédéral de Lausanne (EPFL), Lausanne, Switzerland.,Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Nicholas Renzette
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Timothy F Kowalik
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Jeffrey D Jensen
- School of Life Sciences, École Polytechnique Fédéral de Lausanne (EPFL), Lausanne, Switzerland.,Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| |
Collapse
|
13
|
Novel Method Based on Real-Time Cell Analysis for Drug Susceptibility Testing of Herpes Simplex Virus and Human Cytomegalovirus. J Clin Microbiol 2016; 54:2120-7. [PMID: 27252463 DOI: 10.1128/jcm.03274-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 05/26/2016] [Indexed: 01/23/2023] Open
Abstract
The plaque reduction assay (PRA) is the gold standard phenotypic method to determine herpes simplex virus (HSV) and human cytomegalovirus (HCMV) susceptibilities to antiviral drugs. However, this assay is subjective and labor intensive. Here, we describe a novel antiviral phenotypic method based on real-time cell analysis (RTCA) that measures electronic impedance over time. The effective drug concentrations that reduced by 50% (EC50s) the cytopathic effects induced by HSV-1 and HCMV were evaluated by both methods. The EC50s of acyclovir and foscarnet against a reference wild-type (WT) HSV-1 strain in Vero cells were, respectively, 0.5 μM and 32.6 μM by PRA and 0.8 μM and 93.6 μM by RTCA. The EC50 ratios for acyclovir against several HSV-1 thymidine kinase (TK) mutants were 101.8×, 73.4×, 28.8×, and 35.4× (PRA) and 18.0×, 52.0×, 5.5×, and 87.8× (RTCA) compared to those for the WT. The EC50 ratios for acyclovir and foscarnet against the HSV-1 TK/DNA polymerase mutant were 182.8× and 9.7× (PRA) and >125.0× and 10.8× (RTCA) compared to the WT. The EC50s of ganciclovir and foscarnet against WT HCMV strain AD169 in fibroblasts were, respectively, 1.6 μM and 27.8 μM by PRA and 5.0 μM and 111.4 μM by RTCA. The EC50 ratios of ganciclovir against the HCMV UL97 mutant were 3.8× (PRA) and 8.2× (RTCA) compared to those for the WT. The EC50 ratios of ganciclovir and foscarnet against the HCMV UL97/DNA polymerase mutant were 17.1× and 12.1× (PRA) and 14.7× and 4.6× (RTCA) compared to those for the WT. RTCA allows objective drug susceptibility testing of HSV and HCMV and could permit high-throughput screening of new antivirals.
Collapse
|
14
|
Novel Cytomegalovirus UL54 DNA Polymerase Gene Mutations Selected In Vitro That Confer Brincidofovir Resistance. Antimicrob Agents Chemother 2016; 60:3845-8. [PMID: 27044553 DOI: 10.1128/aac.00214-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/01/2016] [Indexed: 01/11/2023] Open
Abstract
Eight in vitro selection experiments under brincidofovir pressure elicited the known cytomegalovirus DNA polymerase amino acid substitutions N408K and V812L and the novel exonuclease domain substitutions D413Y, E303D, and E303G, which conferred ganciclovir and cidofovir resistance with 6- to 11-fold resistance to brincidofovir or 17-fold when E303G was combined with V812L. The new exonuclease domain I resistance mutations selected under brincidofovir pressure add to the single instance previously reported and show the expected patterns of cross-resistance.
Collapse
|
15
|
Campos AB, Ribeiro J, Boutolleau D, Sousa H. Human cytomegalovirus antiviral drug resistance in hematopoietic stem cell transplantation: current state of the art. Rev Med Virol 2016; 26:161-82. [DOI: 10.1002/rmv.1873] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 01/09/2016] [Accepted: 02/01/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Ana Bela Campos
- Molecular Oncology and Viral Pathology Group (CI-IPOP); Porto Portugal
- Faculty of Medicine; University of Porto; Porto Portugal
| | - Joana Ribeiro
- Molecular Oncology and Viral Pathology Group (CI-IPOP); Porto Portugal
- Virology Service; Portuguese Oncology Institute of Porto; Porto Portugal
- Faculty of Medicine; University of Porto; Porto Portugal
| | - David Boutolleau
- Sorbonne Universités; UPMC Université Paris 06, CR7, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris); Paris France
- INSERM, U1135, CIMI-Paris; Paris France
- AP-HP, Hôpitaux Universitaires La Pitié-Salpêtrière - Charles Foix; Service de Virologie; Paris France
| | - Hugo Sousa
- Molecular Oncology and Viral Pathology Group (CI-IPOP); Porto Portugal
- Virology Service; Portuguese Oncology Institute of Porto; Porto Portugal
| |
Collapse
|
16
|
Contrasting effects of W781V and W780V mutations in helix N of herpes simplex virus 1 and human cytomegalovirus DNA polymerases on antiviral drug susceptibility. J Virol 2015; 89:4636-44. [PMID: 25673718 DOI: 10.1128/jvi.03360-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED DNA polymerases of the Herpesviridae and bacteriophage RB69 belong to the α-like DNA polymerase family. In spite of similarities in structure and function, the RB69 enzyme is relatively resistant to foscarnet, requiring the mutation V478W in helix N to promote the closed conformation of the enzyme to make it susceptible to the antiviral. Here, we generated recombinant herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV) mutants harboring the revertant in UL30 (W781V) and UL54 (W780V) DNA polymerases, respectively, to further investigate the impact of this tryptophan on antiviral drug susceptibility and viral replicative capacity. The mutation W781V in HSV-1 induced resistance to foscarnet, acyclovir, and ganciclovir (3-, 14-, and 3-fold increases in the 50% effective concentrations [EC50s], respectively). The recombinant HCMV mutant harboring the W780V mutation was slightly resistant to foscarnet (a 1.9-fold increase in the EC50) and susceptible to ganciclovir. Recombinant HSV-1 and HCMV mutants had altered viral replication kinetics. The apparent inhibition constant values of foscarnet against mutant UL30 and UL54 DNA polymerases were 45- and 4.9-fold higher, respectively, than those against their wild-type counterparts. Structural evaluation of the tryptophan position in the UL54 DNA polymerase suggests that the bulkier phenylalanine (fingers domain) and isoleucine (N-terminal domain) could induce a tendency toward the closed conformation greater than that for UL30 and explains the modest effect of the W780V mutation on foscarnet susceptibility. Our results further suggest a role of the tryptophan in helix N in conferring HCMV and especially HSV-1 susceptibility to foscarnet and the possible contribution of other residues localized at the interface between the fingers and N-terminal domains. IMPORTANCE DNA polymerases of the Herpesviridae and bacteriophage RB69 belong to the α-like DNA polymerase family. However, the RB69 DNA polymerase is relatively resistant to the broad-spectrum antiviral agent foscarnet. The mutation V478W in helix N of the fingers domain caused the enzyme to adopt a closed conformation and to become susceptible to the antiviral. We generated recombinant herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV) mutants harboring the revertant in UL30 (W781V) and UL54 (W780V) DNA polymerases, respectively, to further investigate the impact of this tryptophan on antiviral drug susceptibility. The W781V mutation in HSV-1 induced resistance to foscarnet, whereas the W780V mutation in HCMV slightly decreased drug susceptibility. This study suggests that the different profiles of susceptibility to foscarnet of the HSV-1 and HCMV mutants could be related to subtle conformational changes resulting from the interaction between residues specific to each enzyme that are located at the interface between the fingers and the N-terminal domains.
Collapse
|
17
|
Göhring K, Hamprecht K, Jahn G. Antiviral Drug- and Multidrug Resistance in Cytomegalovirus Infected SCT Patients. Comput Struct Biotechnol J 2015; 13:153-9. [PMID: 25750703 PMCID: PMC4348572 DOI: 10.1016/j.csbj.2015.01.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 01/23/2023] Open
Abstract
In pediatric and adult patients after stem cell transplantation (SCT) disseminated infections caused by human cytomegalovirus (HCMV) can cause life threatening diseases. For treatment, the three antivirals ganciclovir (GCV), foscarnet (PFA) and cidofovir (CDV) are approved and most frequently used. Resistance to all of these antiviral drugs may induce a severe problem in this patient cohort. Responsible for resistance phenomena are mutations in the HCMV phosphotransferase-gene (UL97) and the polymerase-gene (UL54). Most frequently mutations in the UL97-gene are associated with resistance to GCV. Resistance against all three drugs is associated to mutations in the UL54-gene. Monitoring of drug resistance by genotyping is mostly done by PCR-based Sanger sequencing. For phenotyping with cell culture the isolation of HCMV is a prerequisite. The development of multidrug resistance with mutation in both genes is rare, but it is often associated with a fatal outcome. The manifestation of multidrug resistance is mostly associated with combined UL97/UL54-mutations. Normally, mutations in the UL97 gene occur initially followed by UL54 mutation after therapy switch. The appearance of UL54-mutation alone without any detection of UL97-mutation is rare. Interestingly, in a number of patients the UL97 mutation could be detected in specific compartments exclusively and not in blood.
Collapse
Affiliation(s)
- Katharina Göhring
- Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital of Tübingen, 72076 Tübingen, Germany
| | | | | |
Collapse
|
18
|
Mechanism of ganciclovir-induced chain termination revealed by resistant viral polymerase mutants with reduced exonuclease activity. Proc Natl Acad Sci U S A 2014; 111:17462-7. [PMID: 25422422 DOI: 10.1073/pnas.1405981111] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many antiviral and anticancer drugs are nucleoside analogs that target polymerases and cause DNA chain termination. Interestingly, ganciclovir (GCV), the first line of therapy for human cytomegalovirus (HCMV) infections, induces chain termination despite containing the equivalent of a 3'-hydroxyl group. Certain HCMV GCV resistance (GCV(r)) mutations, including ones associated with treatment failures, result in substitutions in the 3'-5' exonuclease (Exo) domain of the catalytic subunit of the viral DNA polymerase (Pol). To investigate how these mutations confer resistance, we overexpressed and purified wild-type (WT) HCMV Pol and three GCV(r) Exo mutants. Kinetic studies provided little support for resistance being due to effects on Pol binding or incorporation of GCV-triphosphate. The mutants were defective for Exo activity on all primer templates tested, including those with primers terminating with GCV, arguing against the mutations increasing excision of the incorporated drug. However, although the WT enzyme terminated DNA synthesis after incorporation of GCV-triphosphate and an additional nucleotide (N+1), the Exo mutants could efficiently synthesize DNA to the end of such primer templates. Notably, the Exo activity of WT Pol rapidly and efficiently degraded N+2 primer templates to N+1 products that were not further degraded. On N+1 primer templates, WT Pol, much more than the Exo mutants, converted the incoming deoxynucleoside triphosphate to its monophosphate, indicative of rapid addition and removal of incorporated nucleotides ("idling"). These results explain how GCV induces chain termination and elucidate a previously unidentified mechanism of antiviral drug resistance.
Collapse
|
19
|
Antiherpesviral DNA Polymerase Inhibitors. Antiviral Res 2014. [DOI: 10.1128/9781555815493.ch1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
20
|
Komatsu TE, Pikis A, Naeger LK, Harrington PR. Resistance of human cytomegalovirus to ganciclovir/valganciclovir: A comprehensive review of putative resistance pathways. Antiviral Res 2014; 101:12-25. [DOI: 10.1016/j.antiviral.2013.10.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 10/20/2013] [Accepted: 10/21/2013] [Indexed: 11/26/2022]
|
21
|
Cytomegalovirus mutants resistant to ganciclovir and cidofovir differ in susceptibilities to synguanol and its 6-ether and 6-thioether derivatives. Antimicrob Agents Chemother 2013; 58:1809-12. [PMID: 24379208 DOI: 10.1128/aac.02544-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The methylenecyclopropane nucleoside (MCPN) analogs synguanol and its 6-alkoxy (MBX2168) and 6-alkylthio (MBX1616) derivatives retained good in vitro activities against several common ganciclovir-resistant UL97 kinase variants of human cytomegalovirus. Foscarnet-MCPN cross-resistance was observed among UL54 polymerase variants. UL54 exonuclease domain ganciclovir-cidofovir dual-resistant variants were remarkably more hypersensitive to these MCPNs than to cyclopropavir, with some 50% effective concentration ratios that were <0.1× the wild type. Different categories of MCPNs may have therapeutically exploitable mechanistic differences in viral DNA polymerase inhibition.
Collapse
|
22
|
James SH, Price NB, Hartline CB, Lanier ER, Prichard MN. Selection and recombinant phenotyping of a novel CMX001 and cidofovir resistance mutation in human cytomegalovirus. Antimicrob Agents Chemother 2013; 57:3321-5. [PMID: 23650158 PMCID: PMC3697342 DOI: 10.1128/aac.00062-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 04/26/2013] [Indexed: 02/07/2023] Open
Abstract
CMX001 is an orally available lipid acyclic nucleotide phosphonate that delivers high intracellular levels of cidofovir (CDV)-diphosphate and exhibits enhanced in vitro antiviral activity against a wide range of double-stranded DNA viruses, including cytomegalovirus (CMV). Mutations in the DNA polymerase of CMV that impart resistance to CDV also render the virus resistant to CMX001. Here, we report a novel resistance mutation that arose under the selective pressure of CMX001. The wild-type CMV strain AD169 was propagated in human foreskin fibroblasts under increasing concentrations of CMX001 over 10 months, and the resulting strain (named CMX001(R)) was less susceptible to CDV and CMX001 in a plaque reduction assay. Genotypic analysis of virus strain CMX001(R) via conventional sequencing of the genes encoding the CMV DNA polymerase (UL54) and UL97 kinase (UL97) demonstrated one mutation that changed the wild-type aspartate to glutamate at position 542 in UL54. A recombinant virus with this novel D542E mutation was generated via bacterial artificial chromosome-mediated marker transfer experiments. Subsequent phenotypic resistance analysis of the D542E mutant demonstrated reductions in susceptibility of greater than 10-fold to CMX001 and CDV, but no resistance to foscarnet (FOS) or ganciclovir (GCV). Analysis of replicative fitness showed that both strain CMX001(R) and the D542E mutant viruses demonstrated a smaller plaque phenotype and slower replication kinetics than their respective parent viruses. These data describe the first resistance mutation generated under the selective pressure of CMX001 and suggest that CMX001 may have a unique resistance profile associated with reduced viral replication and maintenance of sensitivity to FOS and GCV.
Collapse
Affiliation(s)
- Scott H. James
- University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Nathan B. Price
- University of Alabama at Birmingham, Birmingham, Alabama, USA
| | | | | | | |
Collapse
|
23
|
Magee WC, Evans DH. The antiviral activity and mechanism of action of (S)-[3-hydroxy-2-(phosphonomethoxy)propyl] (HPMP) nucleosides. Antiviral Res 2012; 96:169-80. [PMID: 22960154 DOI: 10.1016/j.antiviral.2012.08.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 08/20/2012] [Accepted: 08/27/2012] [Indexed: 12/18/2022]
Abstract
One class of compounds that has shown promise as antiviral agents are the (S)-[3-hydroxy-2-(phosphonomethoxy)propyl] (HPMP) nucleosides, members of the broader class of acyclic nucleoside phosphonates. These HPMP nucleosides are nucleotide analogs and have been shown to be effective inhibitors of a wide range of DNA viruses. Prodrugs of these compounds, which achieve higher levels of the active metabolites within the cell, have an expanded activity spectrum that also includes RNA viruses and retroviruses. Because they are analogs of natural nucleotide substrates, HPMP nucleosides are predicted to target polymerases (DNA polymerases, RNA polymerases and reverse transcriptases), resulting in the inhibition of viral genome replication. Previous work using the replicative enzymes of different viruses including human cytomegalovirus (HCMV) and vaccinia virus DNA polymerases and human immunodeficiency virus type 1 (HIV-1) reverse transcriptase has shown that the activated forms of these compounds are substrates for viral polymerases and that incorporation of these compounds into either the primer strand or the template strand inhibits, but does not necessarily terminate, further nucleic acid synthesis. The activity of these compounds against other viruses that do not encode their own polymerases, like polyoma viruses and papilloma viruses, suggests that host cell DNA polymerases are also targeted. This complex mechanism of action and broad activity spectrum has implications for the development of resistance and host cell genome replication, and suggests these compounds may be effective against other viruses such as influenza virus, respiratory syncytial virus and Dengue virus. This class of nucleotide analogs also points to a potential avenue for the development of newer antivirals.
Collapse
Affiliation(s)
- Wendy C Magee
- Department of Medical Microbiology and Immunology, Li Ka Shing Institute of Virology, 6-020 Katz Group Centre, University of Alberta, Edmonton, AB, Canada T6G 2E1
| | | |
Collapse
|
24
|
Cyclopropavir susceptibility of cytomegalovirus DNA polymerase mutants selected after antiviral drug exposure. Antimicrob Agents Chemother 2011; 56:197-201. [PMID: 21968367 DOI: 10.1128/aac.05559-11] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human cytomegalovirus (CMV) UL54 DNA polymerase (pol) mutants with known patterns of resistance to current antivirals ganciclovir (GCV), foscarnet (FOS), and cidofovir (CDV) were tested for cyclopropavir (CPV) susceptibility by a standardized reporter-based yield reduction assay. Exonuclease and A987G (region V) mutations at codons commonly associated with dual GCV-CDV resistance in clinical isolates paradoxically conferred increased CPV susceptibility. Various polymerase catalytic region mutations conferring FOS resistance with variable low-grade GCV and CDV cross-resistance also conferred CPV resistance, with 50% effective concentration (EC(50)) increases of 3- to 13-fold. CPV EC(50) values against several pol mutants were increased about 2-fold by adding UL97 mutation C592G. Propagation of a CMV exonuclease mutant under CPV selected for pol mutations less often than UL97 mutations. In 21 experiments, one instance each of mutations E756D and M844V, which were shown individually to confer 3- to 4-fold increases in CPV EC(50), was detected. Unlike GCV and CDV, exonuclease mutations are not a preferred mechanism of CPV resistance, but mutations in and near pol region III may confer CPV resistance by affecting its recognition as an incoming base for DNA polymerization.
Collapse
|
25
|
Recombinant phenotyping of cytomegalovirus UL54 mutations that emerged during cell passages in the presence of either ganciclovir or foscarnet. Antimicrob Agents Chemother 2011; 55:4019-27. [PMID: 21709106 DOI: 10.1128/aac.00334-11] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Selection of human cytomegalovirus variants in the presence of ganciclovir or foscarnet led to 18 DNA polymerase mutations, 14 of which had not been previously studied. Using bacterial artificial chromosome technology, each of these mutations was individually transferred into the genome of a reference strain. Following reconstitution of infectious viral stocks, each mutant was assessed for its drug susceptibility and growth kinetics in cell culture. Computer-assisted three-dimensional (3D) modeling of the polymerase was also used to position each of the mutations in one of four proposed structural domains and to predict their influence on structural stability of the protein. Among the 10 DNA polymerase mutations selected with ganciclovir, 7 (P488R, C539R, L545S, V787L, V812L, P829S, and L862F) were associated with ganciclovir resistance, whereas 2 (F595I and V946L) conferred only foscarnet resistance. Among the eight mutations selected with foscarnet, only two (T552N and S585A) conferred foscarnet resistance, whereas four (N408D, K500N, L802V, and L957F) had an impact on ganciclovir susceptibility. Surprisingly, the combination of mutations, some of which were not associated with resistance for a specific antiviral, resulted in increasing resistance effects. 3D modeling suggested that none of the mutated residues were directly involved in the polymerase catalytic site but rather had an influence on drug susceptibility by modifying the structural flexibility of the protein. Our study significantly adds to the number of DNA polymerase mutations conferring in vitro drug resistance and emphasizes the point that evaluation of individual mutations may not accurately reflect the phenotype conferred by multiple mutations.
Collapse
|
26
|
Abstract
The study of human cytomegalovirus (HCMV) antiviral drug resistance has enhanced knowledge of the virological targets and the mechanisms of antiviral activity. The currently approved drugs, ganciclovir (GCV), foscarnet (FOS), and cidofovir (CDV), target the viral DNA polymerase. GCV anabolism also requires phosphorylation by the virus-encoded UL97 kinase. GCV resistance mutations have been identified in both genes, while FOS and CDV mutations occur only in the DNA polymerase gene. Confirmation of resistance mutations requires phenotypic analysis; however, phenotypic assays are too time-consuming for diagnostic purposes. Genotypic assays based on sequencing provide more rapid results but are dependent on prior validation by phenotypic methods. Reports from many laboratories have produced an evolving list of confirmed resistance mutations, although differences in interpretation have led to some confusion. Recombinant phenotyping methods performed in a few research laboratories have resolved some of the conflicting results. Treatment options for drug-resistant HCMV infections are complex and have not been subjected to controlled clinical trials, although consensus guidelines have been proposed. This review summarizes the virological and clinical data pertaining to HCMV antiviral drug resistance.
Collapse
|
27
|
Differentiation between polymorphisms and resistance-associated mutations in human cytomegalovirus DNA polymerase. Antimicrob Agents Chemother 2010; 54:5004-11. [PMID: 20876378 DOI: 10.1128/aac.00259-10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Specific mutations in the human cytomegalovirus (HCMV) DNA polymerase (pUL54) are known to confer resistance against all currently licensed drugs for treatment of HCMV infection and disease. Following the widespread use of antivirals, the occurrence of HCMV drug resistance is constantly increasing. Recently, diagnostic laboratories have started to replace phenotypic drug resistance testing with genotypic resistance testing. However, the reliability and success of genotypic testing highly depend on the availability of high-quality phenotypic resistance data for each individual mutation and for combinations of mutations, with the latter being increasingly found in patients' HCMV isolates. We performed clonal marker transfer experiments to investigate the impacts of 7 different UL54 point mutations and also of combinations of these mutations on drug susceptibility and viral replicative fitness. We show that several mutations-S695T, A972V, K415R, S291P, and A692V-of suspected but uncertain drug susceptibility phenotype, either alone or in combination, were not relevant to antiviral drug resistance. In contrast, the combination of two mutations individually characterized previously-E756K and D413E-conferred high-grade loss of susceptibility to all three antivirals. Our results have been added to the newly available database of all published HCMV resistance mutations (http://www.informatik.uni-ulm.de/ni/mitarbeiter/HKestler/hcmv/index.html). These data will allow better interpretation of genotypic data and further improve the basis for drug resistance testing.
Collapse
|
28
|
Martin M, Goyette N, Boivin G. Contrasting effects on ganciclovir susceptibility and replicative capacity of two mutations at codon 466 of the human cytomegalovirus UL97 gene. J Clin Virol 2010; 49:296-8. [PMID: 20843736 DOI: 10.1016/j.jcv.2010.08.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 08/12/2010] [Accepted: 08/17/2010] [Indexed: 11/15/2022]
Abstract
BACKGROUND Human cytomegalovirus (HCMV) infections cause significant morbidity in immunocompromised hosts. Resistance to ganciclovir is predominantly associated with alterations in the HCMV UL97 kinase and, more occasionally, with mutations in the HCMV DNA polymerase gene. OBJECTIVES The aim of this study was to investigate the impact of two different mutations found at the same UL97 codon on drug susceptibility and viral replicative capacity. Mutation V466G was observed in a solid organ transplant recipient whereas mutation V466M was observed in a patient with AIDS. STUDY DESIGN Two HCMV UL97 mutations, V466M and V466G, were transferred to recombinant viruses using a bacterial artificial chromosome system. Susceptibility testing of the recombinant wild-type and mutant viruses was performed using a standard plaque reduction assay. Replication kinetics of recombinant viruses was investigated using a yield assay. RESULTS Mutant V466G was resistant to ganciclovir and had significant replicative defect whereas mutant V466M was drug susceptible and had unaltered replication kinetics. Furthermore, mutant V466G formed small viral plaques with intracellular inclusions. CONCLUSIONS To our knowledge, this is the first report of such contrasting phenotypes for drug susceptibility and replicative capacity for HCMV mutations found at the same codon of the UL97 gene.
Collapse
Affiliation(s)
- Mélanie Martin
- Research Center in Infectious Diseases, Centre Hospitalier Universitaire de Québec and Laval University, Quebec City, Quebec, Canada
| | | | | |
Collapse
|
29
|
Chevillotte M, von Einem J, Meier BM, Lin FM, Kestler HA, Mertens T. A new tool linking human cytomegalovirus drug resistance mutations to resistance phenotypes. Antiviral Res 2010; 85:318-27. [DOI: 10.1016/j.antiviral.2009.10.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 10/02/2009] [Accepted: 10/10/2009] [Indexed: 11/25/2022]
|
30
|
Agut H, Boutolleau D, Deback C, Bonnafous P, Gautheret-Dejean A. Testing the susceptibility of human herpesviruses to antivirals. Future Microbiol 2010; 4:1111-23. [PMID: 19895215 DOI: 10.2217/fmb.09.83] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Herpesviruses cause chronic lifelong infections in humans and may cause life-threatening diseases in immunosuppressed patients. Antiviral drugs targeted to viral DNA polymerase, such as acyclovir, penciclovir, ganciclovir, foscarnet and cidofovir, are currently available and have been proven to be efficient against clinical symptoms of herpesvirus infections. The resistance of herpesviruses to these drugs is associated with specific mutations of viral genes encoding either DNA polymerase or enzymes phosphorylating nucleoside analogs. Resistance is detected and characterized by means of specific susceptibility assays, which can be classified as phenotypic, genetic and functional. These tests are used both to investigate novel antiviral compounds and look for the emergence of resistant viruses in treated patients in case of clinical failure. Although susceptibility assays are often time consuming and present some limitations regarding the interpretation of their results, their use in the monitoring of antiherpetic treatments should be promoted and improved, in parallel to the development of novel efficient drugs.
Collapse
Affiliation(s)
- Henri Agut
- Service de Virologie AP-HP, ER DETIV UPMC, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
| | | | | | | | | |
Collapse
|
31
|
Martin M, Azzi A, Lin SX, Boivin G. Opposite effect of two cytomegalovirus DNA polymerase mutations on replicative capacity and polymerase activity. Antivir Ther 2010; 15:579-86. [DOI: 10.3851/imp1565] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
32
|
Tchesnokov EP, Obikhod A, Schinazi RF, Götte M. Engineering of a chimeric RB69 DNA polymerase sensitive to drugs targeting the cytomegalovirus enzyme. J Biol Chem 2009; 284:26439-46. [PMID: 19622750 PMCID: PMC2785332 DOI: 10.1074/jbc.m109.012500] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 06/19/2009] [Indexed: 11/06/2022] Open
Abstract
Detailed structural and biochemical studies with the human cytomegalovirus (HCMV UL54) DNA polymerase are hampered by difficulties to obtain this enzyme in large quantities. The crystal structure of the related RB69 DNA polymerase (gp43) is often used as a model system to explain mechanisms of inhibition of DNA synthesis and drug resistance. However, here we demonstrate that gp43 is approximately 400-fold less sensitive to the pyrophosphate analog foscarnet, when compared with UL54. The RB69 enzyme is also able to discriminate against the nucleotide analog inhibitor acyclovir. In contrast, the HCMV polymerase is able to incorporate this compound with similar efficiency as observed with its natural counterpart. In an attempt to identify major determinants for drug activity, we replaced critical regions of the nucleotide-binding site of gp43 with equivalent regions of the HCMV enzyme. We show that chimeric gp43-UL54 enzymes that contain residues of helix N and helix P of UL54 are resensitized against foscarnet and acyclovir. Changing a region of three amino acids of helix N showed the strongest effects, and changes of two segments of three amino acids in helix P further contributed to the reversal of the phenotype. The engineered chimeric enzyme can be produced in large quantities and may therefore be a valuable surrogate system in drug development efforts. This system may likewise be used for detailed structural and biochemical studies on mechanisms associated with drug action and resistance.
Collapse
Affiliation(s)
- Egor P. Tchesnokov
- From the Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 2B4, Canada and
| | - Aleksandr Obikhod
- the Center for AIDS Research, Department of Pediatrics, Emory University School of Medicine and Veterans Affairs Medical Research, Atlanta, Georgia 30322
| | - Raymond F. Schinazi
- the Center for AIDS Research, Department of Pediatrics, Emory University School of Medicine and Veterans Affairs Medical Research, Atlanta, Georgia 30322
| | - Matthias Götte
- From the Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 2B4, Canada and
| |
Collapse
|
33
|
Iwasenko JM, Scott GM, Ziegler JB, Rawlinson WD. Emergence and persistence of multiple antiviral-resistant CMV strains in a highly immunocompromised child. J Clin Virol 2007; 40:152-5. [PMID: 17698411 DOI: 10.1016/j.jcv.2007.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 07/03/2007] [Accepted: 07/04/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND The emergence of human cytomegalovirus (CMV) antiviral resistance plays a significant role in disease progression in immunocompromised patients who have received antiviral therapy. OBJECTIVES To determine the pattern of antiviral-resistant CMV strains in a highly immunocompromised child. STUDY DESIGN Retrospective specimens of blood and urine were analysed using PCR-sequencing to identify antiviral-resistant CMV strains containing UL97 or UL54 mutations. RESULTS CMV strains resistant to antiviral agents contributed to disease in a bone marrow transplant recipient with X-linked severe combined immunodeficiency (SCID) treated with ganciclovir (GCV) and foscarnet (FOS). Retrospective analyses detected GCV-resistant CMV (L595S) in a specimen taken after disease progression. This GCV-resistant CMV strain persisted for 1 year, after which time it was no longer detected even though the patient continued to receive GCV. A FOS-resistant strain (T700A) then emerged even though no FOS had been administered in the preceding year. CONCLUSION The detection of antiviral-resistant CMV did not follow the patterns found in other patients tested for antiviral resistance, including emergence of a FOS-resistant strain in the absence of antiviral-selective pressure. These findings indicate the patient's underlying immunosuppressive condition should be considered for diagnosis and management of resistant CMV.
Collapse
Affiliation(s)
- Jenna M Iwasenko
- Virology Research, POWH and UNSW Research Laboratories, Prince of Wales Hospital, Randwick, NSW, Australia
| | | | | | | |
Collapse
|
34
|
Chou S, Marousek GI, Van Wechel LC, Li S, Weinberg A. Growth and drug resistance phenotypes resulting from cytomegalovirus DNA polymerase region III mutations observed in clinical specimens. Antimicrob Agents Chemother 2007; 51:4160-2. [PMID: 17709468 PMCID: PMC2151462 DOI: 10.1128/aac.00736-07] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recombinant phenotyping of cytomegalovirus (CMV) pol region III mutations from clinical specimens showed that T813S and G841A each conferred foscarnet resistance and approximately threefold increased ganciclovir resistance; adding the UL97 mutation C592G increased ganciclovir resistance to approximately sixfold. Bacterial artificial chromosome CMV clones containing pol mutation L845P were nonviable unless repaired with the wild-type sequence.
Collapse
Affiliation(s)
- Sunwen Chou
- Divisionof Infectious Disease, Oregon Health Science University, VA Medical Center, Portland, OR 97239, USA.
| | | | | | | | | |
Collapse
|
35
|
Scalzo AA, Corbett AJ, Rawlinson WD, Scott GM, Degli-Esposti MA. The interplay between host and viral factors in shaping the outcome of cytomegalovirus infection. Immunol Cell Biol 2006; 85:46-54. [PMID: 17146464 DOI: 10.1038/sj.icb.7100013] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cytomegalovirus (CMV) remains a major human pathogen causing significant morbidity and mortality in immunosuppressed or immunoimmature individuals. Although significant advances have been made in dissecting out certain features of the host response to human CMV (HCMV) infection, the strict species specificity of CMVs means that most aspects of antiviral immunity are best assessed in animal models. The mouse model of murine CMV (MCMV) infection is an important tool for analysis of in vivo features of host-virus interactions and responses to antiviral drugs that are difficult to assess in humans. Important studies of the contribution of host resistance genes to infection outcome, interplays between innate and adaptive host immune responses, the contribution of virus immune evasion genes and genetic variation in these genes to the establishment of persistence and in vivo studies of resistance to antiviral drugs have benefited from the well-developed MCMV model. In this review, we discuss recent advances in the immunobiology of host-CMV interactions that provide intriguing insights into the complex interplay between host and virus that ultimately facilitates viral persistence. We also discuss recent studies of genetic responses to antiviral therapy, particularly changes in DNA polymerase and protein kinase genes of MCMV and HCMV.
Collapse
Affiliation(s)
- Anthony A Scalzo
- Immunology and Virology Program, Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia.
| | | | | | | | | |
Collapse
|
36
|
Scott GM, Weinberg A, Rawlinson WD, Chou S. Multidrug resistance conferred by novel DNA polymerase mutations in human cytomegalovirus isolates. Antimicrob Agents Chemother 2006; 51:89-94. [PMID: 17043128 PMCID: PMC1797699 DOI: 10.1128/aac.00633-06] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The emergence of antiviral-resistant cytomegalovirus (CMV) strains is a continuing clinical problem, with increased numbers of immunocompromised patients given longer-duration antiviral prophylaxis. Two previously unrecognized CMV DNA polymerase mutations (N408K and A834P) identified separately and together in at-risk lung and kidney transplant recipients and a third mutation (L737M) identified in a liver transplant recipient were characterized by marker transfer to antiviral-sensitive laboratory strains AD169 and Towne. Subsequent phenotypic analyses of recombinant strains demonstrated the ability of mutation N408K to confer ganciclovir (GCV) and cidofovir (CDV) resistance and of mutation A834P to confer GCV, foscarnet, and CDV resistance. Mutation L737M did not confer resistance to any of the antiviral agents tested. A recombinant strain containing both N408K and A834P demonstrated increased GCV and CDV resistance compared to the levels of resistance of the virus containing only the A834P mutation. The addition of mutation N408K in combination with A834P also partially reconstituted the replication impairment of recombinant virus containing only A834P. This suggests that perturbation of both DNA polymerization (A834P) and exonuclease (N408K) activities contributes to antiviral resistance and altered replication kinetics in these mutant strains. The identification of these multidrug-resistant CMV strains in at-risk seronegative recipients of organs from seropositive donors suggests that improved prophylactic and treatment strategies are required. The additive effect of multiple mutations on antiviral susceptibility suggests that increasing antiviral-resistant phenotypes can result from different virus-antiviral interactions.
Collapse
Affiliation(s)
- Gillian M Scott
- Virology Research, POWH and UNSW Research Laboratories, Level 3 Clinical Sciences Building, Prince of Wales Hospital, Avoca Street, Randwick, NSW 2031, Australia.
| | | | | | | |
Collapse
|
37
|
Alvisi G, Ripalti A, Ngankeu A, Giannandrea M, Caraffi SG, Dias MM, Jans DA. Human cytomegalovirus DNA polymerase catalytic subunit pUL54 possesses independently acting nuclear localization and ppUL44 binding motifs. Traffic 2006; 7:1322-32. [PMID: 16911590 DOI: 10.1111/j.1600-0854.2006.00477.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The catalytic subunit of human cytomegalovirus (HCMV) DNA polymerase pUL54 is a 1242-amino-acid protein, whose function, stimulated by the processivity factor, phosphoprotein UL44 (ppUL44), is essential for viral replication. The C-terminal residues (amino acids 1220-1242) of pUL54 have been reported to be sufficient for ppUL44 binding in vitro. Although believed to be important for functioning in the nuclei of infected cells, no data are available on either the interaction of pUL54 with ppUL44 in living mammalian cells or the mechanism of pUL54 nuclear transport and its relationship with that of ppUL44. The present study examines for the first time the nuclear import pathway of pUL54 and its interaction with ppUL44 using dual color, quantitative confocal laser scanning microscopy on live transfected cells and quantitative gel mobility shift assays. We showed that of two nuclear localization signals (NLSs) located at amino acids 1153-1159 (NLSA) and 1222-1227 (NLSB), NLSA is sufficient to confer nuclear localization on green fluorescent protein (GFP) by mediating interaction with importin alpha/beta. We also showed that pUL54 residues 1213-1242 are sufficient to confer ppUL44 binding abilities on GFP and that pUL54 and ppUL44 can be transported to the nucleus as a complex. Our work thus identified distinct sites within the HCMV DNA polymerase, which represent potential therapeutic targets and establishes the molecular basis of UL54 nuclear import.
Collapse
Affiliation(s)
- Gualtiero Alvisi
- Dipartimento di Medicina Clinica Specialistica e Sperimentale, Sezione di Microbiologia, Università degli Studi di Bologna, via Massarenti 9, 40138 Bologna, Italy.
| | | | | | | | | | | | | |
Collapse
|
38
|
Shi R, Azzi A, Gilbert C, Boivin G, Lin SX. Three-dimensional modeling of cytomegalovirus DNA polymerase and preliminary analysis of drug resistance. Proteins 2006; 64:301-7. [PMID: 16705640 DOI: 10.1002/prot.21005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cytomegalovirus (CMV) is the leading cause of congenital infection and a frequent opportunistic agent in immunocompromised hosts such as transplant recipients and AIDS patients. CMV DNA polymerase, a member of the polymerase B family, is the primary target of all available antivirals (ganciclovir, cidofovir, and foscarnet) and certain variations of this enzyme could lead to drug resistance. However, understanding the drug resistance mechanisms at the atomic level is hampered by the lack of its three-dimensional (3D) structure. In the present work, 3D models of two different conformations (closed and open) for CMV DNA polymerase have been built based on the crystal structures of bacteriophage RB69 DNA polymerase (a member of the polymerase B family) by using the 3D-Jury Meta server and the program MODELLER. Most of the variations on CMV DNA polymerase pertinent to ganciclovir/cidofovir and foscarnet resistance can be explained well based on the open and closed conformation models, respectively. These results constitute a first step towards facilitating our understanding of drug resistance mechanisms for CMV and the interpretation of novel viral mutations.
Collapse
Affiliation(s)
- Rong Shi
- Research Center in Molecular Endocrinology, Centre Hospitalier Universitaire de Québec (CHUL hospital) and Laval University, Québec City, Canada
| | | | | | | | | |
Collapse
|
39
|
Gilbert C, Boivin G. New reporter cell line to evaluate the sequential emergence of multiple human cytomegalovirus mutations during in vitro drug exposure. Antimicrob Agents Chemother 2006; 49:4860-6. [PMID: 16304146 PMCID: PMC1315956 DOI: 10.1128/aac.49.12.4860-4866.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We developed a new reporter cell line for human cytomegalovirus (HCMV) drug susceptibility testing. This cell line was obtained by incorporating the luciferase reporter gene under the control of an HCMV-specific promoter into the genome of astrocytoma cells (U373MG). We then used our reporter cell line to evaluate phenotypic changes conferred by the sequential emergence of HCMV UL54 and UL97 mutations following long-term drug exposure. The laboratory strain AD169 was passaged in the presence of increasing concentrations of ganciclovir (one viral line) or foscarnet (two viral lines). Resistant viruses were plaque purified at five different concentrations of ganciclovir and at three different concentrations of foscarnet. In addition to the previously described M460I and L595S UL97 mutations and the L545S and V812L UL54 mutations, exposition to ganciclovir (up to 3,000 microM) resulted in the selection of two unreported UL54 mutations (P829S and D879G). Passages in the presence of foscarnet (up to 3,000 microM) resulted in the selection of seven not previously described UL54 mutations (K500N, T552N, S585A, N757K, L802V, L926V, and L957F) in addition to the N408D mutation that has been associated with ganciclovir and cidofovir resistance. Long-term exposure of HCMV to either ganciclovir or foscarnet ultimately resulted in the selection of multiple UL54 mutations that conferred high levels of resistance to all approved HCMV DNA polymerase inhibitors, i.e., ganciclovir, cidofovir, and foscarnet. Emergence of each viral mutation conferred stepwise increases in drug 50% inhibitory concentrations that could be objectively measured with the new reporter cell assay.
Collapse
Affiliation(s)
- C Gilbert
- Research Center in Infectious Diseases of the Centre Hospitalier Universitaire de Québec, Canada
| | | |
Collapse
|
40
|
Tchesnokov EP, Gilbert C, Boivin G, Götte M. Role of helix P of the human cytomegalovirus DNA polymerase in resistance and hypersusceptibility to the antiviral drug foscarnet. J Virol 2006; 80:1440-50. [PMID: 16415021 PMCID: PMC1346920 DOI: 10.1128/jvi.80.3.1440-1450.2006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mutations in the human cytomegalovirus DNA polymerase (UL54) can not only decrease but also increase susceptibility to the pyrophosphate (PP(i)) analogue foscarnet. The proximity of L802M, which confers resistance, and K805Q, which confers hypersusceptibility, suggests a possible unifying mechanism that affects drug susceptibility in one direction or the other. We found that the polymerase activities of L802M- and K805Q-containing mutant enzymes were literally indistinguishable from that of wild-type UL54; however, susceptibility to foscarnet was decreased or increased, respectively. A comparison with the crystal structure model of the related RB69 polymerase suggests that L802 and K805 are located in the conserved alpha-helix P that is implicated in nucleotide binding. Although L802 and K805 do not appear to make direct contacts with the incoming nucleotide, it is conceivable that changes at these residues could exert their effects through the adjacent, highly conserved amino acids Q807 and/or K811. Our data show that a K811A substitution in UL54 causes reductions in rates of nucleotide incorporation. The activity of the Q807A mutant is only marginally affected, while this enzyme shows relatively high levels of resistance to foscarnet. Based on these data, we suggest that L802M exerts its effects through subtle structural changes in alpha-helix P that affect the precise positioning of Q807 and, in turn, its presumptive involvement in binding of foscarnet. In contrast, the removal of a positive charge associated with the K805Q change may facilitate access or increase affinity to the adjacent Q807.
Collapse
Affiliation(s)
- Egor P Tchesnokov
- McGill University, Department of Microbiology and Immunology, Room D-6, Duff Medical Building, 3775 University Street, Montreal, Québec, Canada H3A 2B4
| | | | | | | |
Collapse
|
41
|
De Clercq E, Holý A. Acyclic nucleoside phosphonates: a key class of antiviral drugs. Nat Rev Drug Discov 2005; 4:928-40. [PMID: 16264436 DOI: 10.1038/nrd1877] [Citation(s) in RCA: 500] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Almost 20 years after the broad antiviral activity spectrum of the first acyclic nucleoside phosphonates was described, several of these compounds have become important therapies for DNA virus and retrovirus infections. Here, we review the discovery and development of acyclic nucleoside phosphonates, focusing on cidofovir and its potential in the treatment of various herpes-, papilloma-, polyoma-, adeno- and pox-virus infections, adefovir for the treatment of hepatitis B and tenofovir for the treatment of AIDS and the prevention of HIV infections.
Collapse
Affiliation(s)
- Erik De Clercq
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium.
| | | |
Collapse
|
42
|
Ducancelle A, Alain S, Scieux C, Fillet AM, Petit F, Sanson-Le Pors MJ, Mazeron MC. [A novel colorimetric test to study the susceptibility of human cytomegalovirus DNA polymerase to foscarnet]. ACTA ACUST UNITED AC 2005; 53:551-5. [PMID: 16084026 DOI: 10.1016/j.patbio.2005.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Accepted: 07/07/2005] [Indexed: 11/20/2022]
Abstract
We described a colorimetric method to determine the biochemical phenotype of wild-type and mutated cytomegalovirus (HCMV) DNA polymerases by measuring the incorporation of digoxigenin-labelled nucleotides into the growing DNA chain. Mutations V715M and E756K, which are known to confer foscarnet-resistance, were used as controls. Mutation N495K and a combination of changes K415R and S291P, both observed in foscarnet-resistant isolates, were studied. The mutations were introduced by site-directed mutagenesis into wild-type gene UL54 cloned in an expression vector and then polymerases were synthesised by using a commercially available coupled transcription-translation system. The polymerase activity was measured with and without foscarnet. The activity of polymerases containing the V715M or E756K mutations was inhibited by foscarnet at concentrations 70- and 30-fold higher than that of wild-type polymerase, respectively. Change N495K and combination of K415R and S291P, induced a five- and ten-fold decrease in susceptibility to foscarnet, respectively. The results of this non-radioactive assay were consistent with those obtained with the conventional radioactive assay. Therefore, this novel phenotypic method could be useful for the characterisation of mutations that confer HCMV resistance to foscarnet.
Collapse
Affiliation(s)
- A Ducancelle
- Service de bactériologie-virologie, hôpital Lariboisière, Assistance publique-hôpitaux de Paris, 2 rue Ambroise-Paré, 75010 Paris, France
| | | | | | | | | | | | | |
Collapse
|
43
|
Scott GM, Ng HL, Morton CJ, Parker MW, Rawlinson WD. Murine cytomegalovirus resistant to antivirals has genetic correlates with human cytomegalovirus. J Gen Virol 2005; 86:2141-2151. [PMID: 16033961 DOI: 10.1099/vir.0.80910-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Human cytomegalovirus (HCMV) resistance to antivirals is a significant clinical problem. Murine cytomegalovirus (MCMV) infection of mice is a well-described animal model for in vivo studies of CMV pathogenesis, although the mechanisms of MCMV antiviral susceptibility need elucidation. Mutants resistant to nucleoside analogues aciclovir, adefovir, cidofovir, ganciclovir, penciclovir and valaciclovir, and the pyrophosphate analogue foscarnet were generated by in vitro passage of MCMV (Smith) in increasing concentrations of antiviral. All MCMV antiviral resistant mutants contained DNA polymerase mutations identical or similar to HCMV DNA polymerase mutations known to confer antiviral resistance. Mapping of the mutations onto an MCMV DNA polymerase three-dimensional model generated using the Thermococcus gorgonarius Tgo polymerase crystal structure showed that the DNA polymerase mutations potentially confer resistance through changes in regions surrounding a catalytic aspartate triad. The ganciclovir-, penciclovir- and valaciclovir-resistant isolates also contained mutations within MCMV M97 identical or similar to recognized GCV-resistant mutations of HCMV UL97 protein kinase, and demonstrated cross-resistance to antivirals of the same class. This strongly suggests that MCMV M97 has a similar role to HCMV UL97 in the phosphorylation of nucleoside analogue antivirals. All MCMV mutants demonstrated replication-impaired phenotypes, with the lowest titre and plaque size observed for isolates containing mutations in both DNA polymerase and M97. These findings indicate DNA polymerase and protein kinase regions of potential importance for antiviral susceptibility and replication. The similarities between MCMV and HCMV mutations that arise under antiviral selective pressure increase the utility of MCMV as a model for in vivo studies of CMV antiviral resistance.
Collapse
Affiliation(s)
- G M Scott
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, Kensington 2052, Australia
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Kensington 2052, Australia
- Virology Division, Department of Microbiology, SEALS, Prince of Wales Hospital, Avoca Street, Randwick 2031, Australia
| | - H-L Ng
- Biota Structural Biology Laboratory, St Vincent's Institute, Fitzroy, Victoria 3065, Australia
| | - C J Morton
- Biota Structural Biology Laboratory, St Vincent's Institute, Fitzroy, Victoria 3065, Australia
| | - M W Parker
- Biota Structural Biology Laboratory, St Vincent's Institute, Fitzroy, Victoria 3065, Australia
| | - W D Rawlinson
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, Kensington 2052, Australia
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Kensington 2052, Australia
- Virology Division, Department of Microbiology, SEALS, Prince of Wales Hospital, Avoca Street, Randwick 2031, Australia
| |
Collapse
|
44
|
Affiliation(s)
- C Gilbert
- Research Center in Infectious Diseases of the Centre Hospitalier Universitaire de Québec, Université Laval, Sainte-Foy, Québec, Canada
| | | |
Collapse
|
45
|
Springer KL, Chou S, Li S, Giller RH, Quinones R, Shira JE, Weinberg A. How evolution of mutations conferring drug resistance affects viral dynamics and clinical outcomes of cytomegalovirus-infected hematopoietic cell transplant recipients. J Clin Microbiol 2005; 43:208-13. [PMID: 15634973 PMCID: PMC540138 DOI: 10.1128/jcm.43.1.208-213.2005] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection with cytomegalovirus (CMV) remains a significant cause of morbidity and mortality among hematopoietic cell transplant (HCT) recipients. We describe two pediatric HCT recipients who developed persistent and severe drug-resistant CMV infections. CMV resistance to foscarnet and ganciclovir was detected after only 6 and 11 weeks of therapy, respectively. Viral pol mutations associated with drug resistance in these patients included T838A (a novel mutation) and D588N, which were shown by marker transfer to confer foscarnet and multidrug resistance, respectively. Each of these mutations significantly reduced in vitro replication of CMV, suggesting that they may decrease viral fitness. This finding was further supported by the disappearance of mutations upon withdrawal of antiviral pressure in one patient. Novel antivirals or combination therapy may be required for the treatment of drug-resistant CMV in HCT recipients and perhaps in other severely immunocompromised patients.
Collapse
Affiliation(s)
- Kathryn L Springer
- Division of Infectious Diseases, University of Colorado Health Sciences Center, 4200 E. 9th Ave., C-227, Denver, CO 80220, USA
| | | | | | | | | | | | | |
Collapse
|
46
|
Scott GM, Isaacs MA, Zeng F, Kesson AM, Rawlinson WD. Cytomegalovirus antiviral resistance associated with treatment induced UL97 (protein kinase) and UL54 (DNA polymerase) mutations. J Med Virol 2005; 74:85-93. [PMID: 15258973 DOI: 10.1002/jmv.20150] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
HCMV-related illness due to infections with antiviral resistant virus was verified by phenotypic and genotypic assays in 17% (8/47) of high-risk immunocompromised Australian patients. Selective PCR-sequencing of UL97 (protein kinase; PK) and UL54 (DNA polymerase; DNApol) regions important for antiviral sensitivity, identified the majority (6/8) of resistant strains through detection of mutations known to confer antiviral resistance. Additionally, eight UL54 (DNApol) mutations (N408K, T691S, A692V, S695T, L737M, A834P, V955I, and A972V) of unknown phenotype were identified in six specimens from patients with clinical evidence of antiviral resistant infections. One isolate was resistant to ganciclovir (GCV) and another resistant to PFA on phenotypic testing where mutations in UL97 (PK) or UL54 (DNApol) were not detected, suggesting a loss of correlation between phenotype and genotype. Selective PCR-sequencing of UL97 (PK) and UL54 (DNApol) provided rapid and comprehensive results, but missed some resistance detected by phenotypic assays. A combination of phenotypic and genotypic assays is recommended for complete analysis of CMV antiviral resistance, as well as further definition of the clinical relationship between novel UL54 (DNApol) mutations and antiviral resistance.
Collapse
Affiliation(s)
- G M Scott
- Virology Division, Department of Microbiology, SEALS, Prince of Wales Hospital, Randwick, and School of Medicial Sciences, University of New South Wales, Kensington, Australia
| | | | | | | | | |
Collapse
|
47
|
De Bolle L, Naesens L, De Clercq E. Update on human herpesvirus 6 biology, clinical features, and therapy. Clin Microbiol Rev 2005; 18:217-45. [PMID: 15653828 PMCID: PMC544175 DOI: 10.1128/cmr.18.1.217-245.2005] [Citation(s) in RCA: 341] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human herpesvirus 6 (HHV-6) is a betaherpesvirus that is closely related to human cytomegalovirus. It was discovered in 1986, and HHV-6 literature has expanded considerably in the past 10 years. We here present an up-to-date and complete overview of the recent developments concerning HHV-6 biological features, clinical associations, and therapeutic approaches. HHV-6 gene expression regulation and gene products have been systematically characterized, and the multiple interactions between HHV-6 and the host immune system have been explored. Moreover, the discovery of the cellular receptor for HHV-6, CD46, has shed a new light on HHV-6 cell tropism. Furthermore, the in vitro interactions between HHV-6 and other viruses, particularly human immunodeficiency virus, and their relevance for the in vivo situation are discussed, as well as the transactivating capacities of several HHV-6 proteins. The insight into the clinical spectrum of HHV-6 is still evolving and, apart from being recognized as a major pathogen in transplant recipients (as exemplified by the rising number of prospective clinical studies), its role in central nervous system disease has become increasingly apparent. Finally, we present an overview of therapeutic options for HHV-6 therapy (including modes of action and resistance mechanisms).
Collapse
Affiliation(s)
- Leen De Bolle
- Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belgium
| | | | | |
Collapse
|
48
|
Blackman SC, Lurain NS, Witte DP, Filipovich AH, Groen P, Schleiss MR. Emergence and compartmentalization of fatal multi-drug-resistant cytomegalovirus infection in a patient with autosomal-recessive severe combined immune deficiency. J Pediatr Hematol Oncol 2004; 26:601-5. [PMID: 15342989 DOI: 10.1097/01.mph.0000135283.77668.6a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The authors describe a patient with autosomal-recessive severe combined immunodeficiency (SCID) with severe, multiorgan cytomegalovirus (CMV) disease. In the face of appropriate therapy, the patient developed a 100-fold gradient in viral load across the blood-brain barrier. Disseminated disease, including pneumonitis, contributed to a fatal outcome. Serial genotypic analyses revealed multiple UL97 and UL54 (DNA polymerase) mutations that conferred phenotypic resistance to all currently licensed systemic CMV antivirals.
Collapse
Affiliation(s)
- Samuel C Blackman
- Pediatric Residency Training Program, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA
| | | | | | | | | | | |
Collapse
|
49
|
Fillet AM, Auray L, Alain S, Gourlain K, Imbert BM, Najioullah F, Champier G, Gouarin S, Carquin J, Houhou N, Garrigue I, Ducancelle A, Thouvenot D, Mazeron MC. Natural polymorphism of cytomegalovirus DNA polymerase lies in two nonconserved regions located between domains delta-C and II and between domains III and I. Antimicrob Agents Chemother 2004; 48:1865-8. [PMID: 15105145 PMCID: PMC400574 DOI: 10.1128/aac.48.5.1865-1868.2004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We described the natural polymorphism of cytomegalovirus DNA polymerase in 42 unrelated isolates susceptible to ganciclovir, foscarnet, and cidofovir. All variations, including an eight-amino-acid deletion, were located between domains delta-C and II and between domains III and I, suggesting that these specific residues are not involved in enzymatic functions.
Collapse
Affiliation(s)
- Anne-Marie Fillet
- Virology Laboratories, Hospital AP-HP Pitié-Salpêtrière and University Paris VI, Paris, France.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
De Clercq E. Clinical potential of the acyclic nucleoside phosphonates cidofovir, adefovir, and tenofovir in treatment of DNA virus and retrovirus infections. Clin Microbiol Rev 2004; 16:569-96. [PMID: 14557287 PMCID: PMC207110 DOI: 10.1128/cmr.16.4.569-596.2003] [Citation(s) in RCA: 253] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The acyclic nucleoside phosphonates HPMPC (cidofovir), PMEA (adefovir), and PMPA (tenofovir) have proved to be effective in vitro (cell culture systems) and in vivo (animal models and clinical studies) against a wide variety of DNA virus and retrovirus infections: cidofovir against herpesvirus (herpes simplex virus types 1 and 2 varicella-zoster virus, cytomegalovirus [CMV], Epstein-Barr virus, and human herpesviruses 6, 7, and 8), polyomavirus, papillomavirus, adenovirus, and poxvirus (variola virus, cowpox virus, vaccinia virus, molluscum contagiosum virus, and orf virus) infections; adefovir against herpesvirus, hepadnavirus (human hepatitis B virus), and retrovirus (human immunodeficiency virus types 1 [HIV-1] and 2 [HIV-2], simian immunodeficiency virus, and feline immunodeficiency virus) infections; and tenofovir against both hepadnavirus and retrovirus infections. Cidofovir (Vistide) has been officially approved for the treatment of CMV retinitis in AIDS patients, tenofovir disoproxil fumarate (Viread) has been approved for the treatment of HIV infections (i.e., AIDS), and adefovir dipivoxil (Hepsera) has been approved for the treatment of chronic hepatitis B. Nephrotoxicity is the dose-limiting side effect for cidofovir (Vistide) when used intravenously (5 mg/kg); no toxic side effects have been described for adefovir dipivoxil and tenofovir disoproxil fumarate, at the approved doses (Hepsera at 10 mg orally daily and Viread at 300 mg orally daily).
Collapse
Affiliation(s)
- Erik De Clercq
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium.
| |
Collapse
|