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postgraduate thesis: Mechanism study of a small molecule F18 as a novel anti-HIV-1 non-nucleoside reverse transcriptase inhibitor

TitleMechanism study of a small molecule F18 as a novel anti-HIV-1 non-nucleoside reverse transcriptase inhibitor
Authors
Advisors
Advisor(s):Chen, ZZheng, B
Issue Date2012
PublisherThe University of Hong Kong (Pokfulam, Hong Kong)
Abstract
Non-nucleoside reverse transcriptase inhibitor (NNRTI) is one of the key components of antiretroviral drug regimen against human immunodeficiency virus type-1 (HIV-1) replication. However, the low genetic barriers to drug-resistance or cross-resistance, side effects, as well as the unaffordable cost of NNRTIs compromise their clinical usage. Therefore, to develop novel NNRTIs with potent antiviral activity against HIV-1 becomes a major concern in the treatment and prevention of HIV/AIDS. (+)-Calanolide A, which is a natural product initially extracted from the tropical rainforest tree Calophyllum lanigerum, was identified as an attractive NNRTI against HIV-1 despite virus strains containing drug-resistant K103N/Y181C mutations. In this study, a chemical library was constructed based on the three chiral carbon centers of (+)-Calanolide A. After screening the activity against HIVNL4-3 wild-type and several NNRTI-resistant pseudoviruses, a small molecule 10-chloromethyl-11- demethyl-12-oxo-calanolide A (F18) was identified as novel NNRTI with promising anti-HIV efficacy. Further studies were performed to investigate the antiviral breadth, drug resistance profile and underlying mechanism of the action of F18. F18 consistently displayed a potent activity against primary HIV-1 isolates including various subtypes of M group, CRF01_AE, and laboratory-adapted drug-resistant viruses in PBMC based assay. Moreover, F18 displayed distinct profiles against 17 NNRTI-resistant pseudoviruses, with an excellent potency especially against one of the most prevalent strains with the Y181C mutation (EC50=1.0nM) in cell line based assay, which was in stark contrast from the extensively used NNRTIs nevirapine and efavirenz. F18-resistant viruses were induced by in vitro serial passages, and mutation L100I was appeared to be the dominant contributor to F18-resistance, further suggesting a binding motif different from nevirapine and efavirenz. The efficacy of F18 was non-antagonistic when used in combination with other antiretrovirals against both wild-type and drug-resistant viruses in infected PBMCs. Interestingly, F18 displayed a highly synergistic antiviral effect with nevirapine against nevirapine-resistant virus (Y181C). Furthermore, in silico docking analysis suggested that F18 may bind to the HIV-1 reverse transcriptase in a way different to other NNRTIs. For the potential as an anti-HIV-1 microbicide, F18 also showed the stable and rapid release, as well as the sustained antiviral activity against HIV-1 wild-type virus in a formulation temperature-sensitive acidic gel. In summary, this study presents F18 as a new potential drug for clinical use and also underlies new mechanism-based design for future NNRTI.
DegreeDoctor of Philosophy
SubjectAIDS (Disease) - Chemotherapy.
HIV infections - Chemotherapy.
Reverse transcriptase - Inhibitors - Therapeutic use.
Antiretroviral agents.
Dept/ProgramMicrobiology

 

DC FieldValueLanguage
dc.contributor.advisorChen, Z-
dc.contributor.advisorZheng, B-
dc.contributor.authorLu, Xiaofan.-
dc.contributor.author陆小凡.-
dc.date.issued2012-
dc.description.abstractNon-nucleoside reverse transcriptase inhibitor (NNRTI) is one of the key components of antiretroviral drug regimen against human immunodeficiency virus type-1 (HIV-1) replication. However, the low genetic barriers to drug-resistance or cross-resistance, side effects, as well as the unaffordable cost of NNRTIs compromise their clinical usage. Therefore, to develop novel NNRTIs with potent antiviral activity against HIV-1 becomes a major concern in the treatment and prevention of HIV/AIDS. (+)-Calanolide A, which is a natural product initially extracted from the tropical rainforest tree Calophyllum lanigerum, was identified as an attractive NNRTI against HIV-1 despite virus strains containing drug-resistant K103N/Y181C mutations. In this study, a chemical library was constructed based on the three chiral carbon centers of (+)-Calanolide A. After screening the activity against HIVNL4-3 wild-type and several NNRTI-resistant pseudoviruses, a small molecule 10-chloromethyl-11- demethyl-12-oxo-calanolide A (F18) was identified as novel NNRTI with promising anti-HIV efficacy. Further studies were performed to investigate the antiviral breadth, drug resistance profile and underlying mechanism of the action of F18. F18 consistently displayed a potent activity against primary HIV-1 isolates including various subtypes of M group, CRF01_AE, and laboratory-adapted drug-resistant viruses in PBMC based assay. Moreover, F18 displayed distinct profiles against 17 NNRTI-resistant pseudoviruses, with an excellent potency especially against one of the most prevalent strains with the Y181C mutation (EC50=1.0nM) in cell line based assay, which was in stark contrast from the extensively used NNRTIs nevirapine and efavirenz. F18-resistant viruses were induced by in vitro serial passages, and mutation L100I was appeared to be the dominant contributor to F18-resistance, further suggesting a binding motif different from nevirapine and efavirenz. The efficacy of F18 was non-antagonistic when used in combination with other antiretrovirals against both wild-type and drug-resistant viruses in infected PBMCs. Interestingly, F18 displayed a highly synergistic antiviral effect with nevirapine against nevirapine-resistant virus (Y181C). Furthermore, in silico docking analysis suggested that F18 may bind to the HIV-1 reverse transcriptase in a way different to other NNRTIs. For the potential as an anti-HIV-1 microbicide, F18 also showed the stable and rapid release, as well as the sustained antiviral activity against HIV-1 wild-type virus in a formulation temperature-sensitive acidic gel. In summary, this study presents F18 as a new potential drug for clinical use and also underlies new mechanism-based design for future NNRTI.-
dc.languageeng-
dc.publisherThe University of Hong Kong (Pokfulam, Hong Kong)-
dc.relation.ispartofHKU Theses Online (HKUTO)-
dc.rightsThe author retains all proprietary rights, (such as patent rights) and the right to use in future works.-
dc.rightsCreative Commons: Attribution 3.0 Hong Kong License-
dc.source.urihttp://hub.hku.hk/bib/B47246509-
dc.subject.lcshAIDS (Disease) - Chemotherapy.-
dc.subject.lcshHIV infections - Chemotherapy.-
dc.subject.lcshReverse transcriptase - Inhibitors - Therapeutic use.-
dc.subject.lcshAntiretroviral agents.-
dc.titleMechanism study of a small molecule F18 as a novel anti-HIV-1 non-nucleoside reverse transcriptase inhibitor-
dc.typePG_Thesis-
dc.identifier.hkulb4724650-
dc.description.thesisnameDoctor of Philosophy-
dc.description.thesisleveldoctoral-
dc.description.thesisdisciplineMicrobiology-
dc.description.naturepublished_or_final_version-
dc.identifier.doi10.5353/th_b4724650-
dc.date.hkucongregation2012-

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