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Tillmanns J, Kicuntod J, Lösing J, Marschall M. 'Getting Better'-Is It a Feasible Strategy of Broad Pan-Antiherpesviral Drug Targeting by Using the Nuclear Egress-Directed Mechanism? Int J Mol Sci 2024; 25:2823. [PMID: 38474070 DOI: 10.3390/ijms25052823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 02/24/2024] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
The herpesviral nuclear egress represents an essential step of viral replication efficiency in host cells, as it defines the nucleocytoplasmic release of viral capsids. Due to the size limitation of the nuclear pores, viral nuclear capsids are unable to traverse the nuclear envelope without a destabilization of this natural host-specific barrier. To this end, herpesviruses evolved the regulatory nuclear egress complex (NEC), composed of a heterodimer unit of two conserved viral NEC proteins (core NEC) and a large-size extension of this complex including various viral and cellular NEC-associated proteins (multicomponent NEC). Notably, the NEC harbors the pronounced ability to oligomerize (core NEC hexamers and lattices), to multimerize into higher-order complexes, and, ultimately, to closely interact with the migrating nuclear capsids. Moreover, most, if not all, of these NEC proteins comprise regulatory modifications by phosphorylation, so that the responsible kinases, and additional enzymatic activities, are part of the multicomponent NEC. This sophisticated basis of NEC-specific structural and functional interactions offers a variety of different modes of antiviral interference by pharmacological or nonconventional inhibitors. Since the multifaceted combination of NEC activities represents a highly conserved key regulatory stage of herpesviral replication, it may provide a unique opportunity towards a broad, pan-antiherpesviral mechanism of drug targeting. This review presents an update on chances, challenges, and current achievements in the development of NEC-directed antiherpesviral strategies.
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Affiliation(s)
- Julia Tillmanns
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Jintawee Kicuntod
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Josephine Lösing
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Manfred Marschall
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
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Yu D, Wagner S, Schütz M, Jeon Y, Seo M, Kim J, Brückner N, Kicuntod J, Tillmanns J, Wangen C, Hahn F, Kaufer BB, Neipel F, Eickhoff J, Klebl B, Nam K, Marschall M. An Antiherpesviral Host-Directed Strategy Based on CDK7 Covalently Binding Drugs: Target-Selective, Picomolar-Dose, Cross-Virus Reactivity. Pharmaceutics 2024; 16:158. [PMID: 38399219 PMCID: PMC10892818 DOI: 10.3390/pharmaceutics16020158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/12/2024] [Accepted: 01/18/2024] [Indexed: 02/25/2024] Open
Abstract
The repertoire of currently available antiviral drugs spans therapeutic applications against a number of important human pathogens distributed worldwide. These include cases of the pandemic severe acute respiratory coronavirus type 2 (SARS-CoV-2 or COVID-19), human immunodeficiency virus type 1 (HIV-1 or AIDS), and the pregnancy- and posttransplant-relevant human cytomegalovirus (HCMV). In almost all cases, approved therapies are based on direct-acting antivirals (DAAs), but their benefit, particularly in long-term applications, is often limited by the induction of viral drug resistance or side effects. These issues might be addressed by the additional use of host-directed antivirals (HDAs). As a strong input from long-term experiences with cancer therapies, host protein kinases may serve as HDA targets of mechanistically new antiviral drugs. The study demonstrates such a novel antiviral strategy by targeting the major virus-supportive host kinase CDK7. Importantly, this strategy focuses on highly selective, 3D structure-derived CDK7 inhibitors carrying a warhead moiety that mediates covalent target binding. In summary, the main experimental findings of this study are as follows: (1) the in vitro verification of CDK7 inhibition and selectivity that confirms the warhead covalent-binding principle (by CDK-specific kinase assays), (2) the highly pronounced antiviral efficacies of the hit compounds (in cultured cell-based infection models) with half-maximal effective concentrations that reach down to picomolar levels, (3) a particularly strong potency of compounds against strains and reporter-expressing recombinants of HCMV (using infection assays in primary human fibroblasts), (4) additional activity against further herpesviruses such as animal CMVs and VZV, (5) unique mechanistic properties that include an immediate block of HCMV replication directed early (determined by Western blot detection of viral marker proteins), (6) a substantial drug synergism in combination with MBV (measured by a Loewe additivity fixed-dose assay), and (7) a strong sensitivity of clinically relevant HCMV mutants carrying MBV or ganciclovir resistance markers. Combined, the data highlight the huge developmental potential of this host-directed antiviral targeting concept utilizing covalently binding CDK7 inhibitors.
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Affiliation(s)
- DongHoon Yu
- Qurient Co., Ltd., C-Dong, 242 Pangyo-ro, C801 Bundang-gu, Seongnam-si 13487, Republic of Korea
| | - Sabrina Wagner
- Institute for Clinical and Molecular Virolosgy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany
| | - Martin Schütz
- Institute for Clinical and Molecular Virolosgy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany
| | - Yeejin Jeon
- Qurient Co., Ltd., C-Dong, 242 Pangyo-ro, C801 Bundang-gu, Seongnam-si 13487, Republic of Korea
| | - Mooyoung Seo
- Qurient Co., Ltd., C-Dong, 242 Pangyo-ro, C801 Bundang-gu, Seongnam-si 13487, Republic of Korea
| | - Jaeseung Kim
- Qurient Co., Ltd., C-Dong, 242 Pangyo-ro, C801 Bundang-gu, Seongnam-si 13487, Republic of Korea
| | - Nadine Brückner
- Institute for Clinical and Molecular Virolosgy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany
| | - Jintawee Kicuntod
- Institute for Clinical and Molecular Virolosgy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany
| | - Julia Tillmanns
- Institute for Clinical and Molecular Virolosgy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany
| | - Christina Wangen
- Institute for Clinical and Molecular Virolosgy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany
| | - Friedrich Hahn
- Institute for Clinical and Molecular Virolosgy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany
| | - Benedikt B. Kaufer
- Institute of Virology, Freie Universität Berlin, Robert-von-Ostertag-Straße 7–13, 14163 Berlin, Germany
| | - Frank Neipel
- Institute for Clinical and Molecular Virolosgy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany
| | - Jan Eickhoff
- Lead Discovery Center GmbH, Otto-Hahn-Straße 15, 44227 Dortmund, Germany
| | - Bert Klebl
- Lead Discovery Center GmbH, Otto-Hahn-Straße 15, 44227 Dortmund, Germany
- The Norwegian College of Fishery Science UiT, Arctic University of Norway, 9037 Tromsø, Norway
| | - Kiyean Nam
- Qurient Co., Ltd., C-Dong, 242 Pangyo-ro, C801 Bundang-gu, Seongnam-si 13487, Republic of Korea
| | - Manfred Marschall
- Institute for Clinical and Molecular Virolosgy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany
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Wild M, Karner D, Eickhoff J, Wagner S, Kicuntod J, Chang W, Barry P, Jonjić S, Lenac Roviš T, Marschall M. Combined Treatment with Host-Directed and Anticytomegaloviral Kinase Inhibitors: Mechanisms, Synergisms and Drug Resistance Barriers. Pharmaceutics 2023; 15:2680. [PMID: 38140021 PMCID: PMC10748244 DOI: 10.3390/pharmaceutics15122680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/20/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023] Open
Abstract
Despite the availability of currently approved antiviral drugs, infections with human cytomegalovirus (HCMV) still cause clinically challenging, sometimes life-threatening situations. There is an urgent need for enhanced anti-HCMV drugs that offer improved efficacy, reduced dosages and options for long-term treatment without risk of the development of viral drug resistance. Recently, we reported the pronounced anti-HCMV efficacy of pharmacological inhibitors of cyclin-dependent kinases (CDKs), in particular, the potential of utilizing drug synergies upon combination treatment with inhibitors of host CDKs and the viral CDK-like kinase pUL97 (vCDK/pUL97). Here, we expand this finding by further assessing the in vitro synergistic antiviral interaction between vCDK and CDK inhibitors towards HCMV as well as non-human cytomegaloviruses. An extension of this synergy approach was achieved in vivo by using the recombinant MCMV-UL97/mouse model, confirming the high potential of combination treatment with the clinically approved vCDK inhibitor maribavir (MBV) and the developmental CDK7 inhibitor LDC4297. Moreover, mechanistic aspects of this synergistic drug combination were illustrated on the levels of intracellular viral protein transport and viral genome replication. The analysis of viral drug resistance did not reveal resistance formation in the case of MBV + LDC4297 combination treatment. Spanning various investigational levels, these new results strongly support our concept, employing the great potential of anti-HCMV synergistic drug treatment.
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Affiliation(s)
- Markus Wild
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany; (M.W.); (S.W.); (J.K.)
| | - Dubravka Karner
- Center for Proteomics, Faculty of Medicine, University of Rijeka, Brace Branchetta 20, 51000 Rijeka, Croatia; (D.K.); (S.J.); (T.L.R.)
| | - Jan Eickhoff
- Lead Discovery Center GmbH, Otto-Hahn-Str. 15, 44227 Dortmund, Germany;
| | - Sabrina Wagner
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany; (M.W.); (S.W.); (J.K.)
| | - Jintawee Kicuntod
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany; (M.W.); (S.W.); (J.K.)
| | - William Chang
- Department of Medical Microbiology and Immunology, California National Primate Research Center, University of California, 3146 Tupper Hall, 1 Shields Avenue, Davis, CA 95616, USA; (W.C.); (P.B.)
| | - Peter Barry
- Department of Medical Microbiology and Immunology, California National Primate Research Center, University of California, 3146 Tupper Hall, 1 Shields Avenue, Davis, CA 95616, USA; (W.C.); (P.B.)
| | - Stipan Jonjić
- Center for Proteomics, Faculty of Medicine, University of Rijeka, Brace Branchetta 20, 51000 Rijeka, Croatia; (D.K.); (S.J.); (T.L.R.)
| | - Tihana Lenac Roviš
- Center for Proteomics, Faculty of Medicine, University of Rijeka, Brace Branchetta 20, 51000 Rijeka, Croatia; (D.K.); (S.J.); (T.L.R.)
| | - Manfred Marschall
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany; (M.W.); (S.W.); (J.K.)
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Tillmanns J, Häge S, Borst EM, Wardin J, Eickhoff J, Klebl B, Wagner S, Wangen C, Hahn F, Socher E, Marschall M. Assessment of Covalently Binding Warhead Compounds in the Validation of the Cytomegalovirus Nuclear Egress Complex as an Antiviral Target. Cells 2023; 12:cells12081162. [PMID: 37190072 DOI: 10.3390/cells12081162] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/06/2023] [Accepted: 04/06/2023] [Indexed: 05/17/2023] Open
Abstract
Herpesviral nuclear egress is a regulated process of viral capsid nucleocytoplasmic release. Due to the large capsid size, a regular transport via the nuclear pores is unfeasible, so that a multistage-regulated export pathway through the nuclear lamina and both leaflets of the nuclear membrane has evolved. This process involves regulatory proteins, which support the local distortion of the nuclear envelope. For human cytomegalovirus (HCMV), the nuclear egress complex (NEC) is determined by the pUL50-pUL53 core that initiates multicomponent assembly with NEC-associated proteins and capsids. The transmembrane NEC protein pUL50 serves as a multi-interacting determinant that recruits regulatory proteins by direct and indirect contacts. The nucleoplasmic core NEC component pUL53 is strictly associated with pUL50 in a structurally defined hook-into-groove complex and is considered as the potential capsid-binding factor. Recently, we validated the concept of blocking the pUL50-pUL53 interaction by small molecules as well as cell-penetrating peptides or an overexpression of hook-like constructs, which can lead to a pronounced degree of antiviral activity. In this study, we extended this strategy by utilizing covalently binding warhead compounds, originally designed as binders of distinct cysteine residues in target proteins, such as regulatory kinases. Here, we addressed the possibility that warheads may likewise target viral NEC proteins, building on our previous crystallization-based structural analyses that revealed distinct cysteine residues in positions exposed from the hook-into-groove binding surface. To this end, the antiviral and NEC-binding properties of a selection of 21 warhead compounds were investigated. The combined findings are as follows: (i) warhead compounds exhibited a pronounced anti-HCMV potential in cell-culture-based infection models; (ii) computational analysis of NEC primary sequences and 3D structures revealed cysteine residues exposed to the hook-into-groove interaction surface; (iii) several of the active hit compounds exhibited NEC-blocking activity, as shown at the single-cell level by confocal imaging; (iv) the clinically approved warhead drug ibrutinib exerted a strong inhibitory impact on the pUL50-pUL53 core NEC interaction, as demonstrated by the NanoBiT assay system; and (v) the generation of recombinant HCMV ∆UL50-ΣUL53, allowing the assessment of viral replication under conditional expression of the viral core NEC proteins, was used for characterizing viral replication and a mechanistic evaluation of ibrutinib antiviral efficacy. Combined, the results point to a rate-limiting importance of the HCMV core NEC for viral replication and to the option of exploiting this determinant by the targeting of covalently NEC-binding warhead compounds.
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Affiliation(s)
- Julia Tillmanns
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Sigrun Häge
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Eva Maria Borst
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany
| | - Julia Wardin
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Jan Eickhoff
- Lead Discovery Center GmbH (LDC), 44227 Dortmund, Germany
| | - Bert Klebl
- Lead Discovery Center GmbH (LDC), 44227 Dortmund, Germany
- The Norwegian College of Fishery Science UiT, The Arctic University of Norway, 9037 Tromsø, Norway
| | - Sabrina Wagner
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Christina Wangen
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Friedrich Hahn
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Eileen Socher
- Institute of Anatomy, Functional and Clinical Anatomy, FAU, 91054 Erlangen, Germany
| | - Manfred Marschall
- Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
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