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Mishra V, Deshmukh A, Rathore I, Chakraborty S, Patankar S, Gustchina A, Wlodawer A, Yada RY, Bhaumik P. Inhibition of Plasmodium falciparum plasmepsins by drugs targeting HIV-1 protease: A way forward for antimalarial drug discovery. Curr Res Struct Biol 2024; 7:100128. [PMID: 38304146 PMCID: PMC10830516 DOI: 10.1016/j.crstbi.2024.100128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/09/2024] [Accepted: 01/11/2024] [Indexed: 02/03/2024] Open
Abstract
Plasmodium species are causative agents of malaria, a disease that is a serious global health concern. FDA-approved HIV-1 protease inhibitors (HIV-1 PIs) have been reported to be effective in reducing the infection by Plasmodium parasites in the population co-infected with both HIV-1 and malaria. However, the mechanism of HIV-1 PIs in mitigating Plasmodium pathogenesis during malaria/HIV-1 co-infection is not fully understood. In this study we demonstrate that HIV-1 drugs ritonavir (RTV) and lopinavir (LPV) exhibit the highest inhibition activity against plasmepsin II (PMII) and plasmepsin X (PMX) of P. falciparum. Crystal structures of the complexes of PMII with both drugs have been determined. The inhibitors interact with PMII via multiple hydrogen bonding and hydrophobic interactions. The P4 moiety of RTV forms additional interactions compared to LPV and exhibits conformational flexibility in a large S4 pocket of PMII. Our study is also the first to report inhibition of P. falciparum PMX by RTV and the mode of binding of the drug to the PMX active site. Analysis of the crystal structures implies that PMs can accommodate bulkier groups of these inhibitors in their S4 binding pockets. Structurally similar active sites of different vacuolar and non-vacuolar PMs suggest the potential of HIV-1 PIs in targeting these enzymes with differential affinities. Our structural investigations and biochemical data emphasize PMs as crucial targets for repurposing HIV-1 PIs as antimalarial drugs.
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Affiliation(s)
- Vandana Mishra
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Anuradha Deshmukh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Ishan Rathore
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
- Protein Structure Section, Center for Structural Biology, National Cancer Institute, Frederick, MD, 21702, USA
| | - Satadru Chakraborty
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Swati Patankar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Alla Gustchina
- Protein Structure Section, Center for Structural Biology, National Cancer Institute, Frederick, MD, 21702, USA
| | - Alexander Wlodawer
- Protein Structure Section, Center for Structural Biology, National Cancer Institute, Frederick, MD, 21702, USA
| | - Rickey Y. Yada
- Faculty of Land and Food Systems, University of British Columbia, 248-2357 Main Mall, Vancouver, BC V6T 1Z4, Vancouver, Canada
| | - Prasenjit Bhaumik
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
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Tanneru N, Nivya MA, Adhikari N, Saxena K, Rizvi Z, Sudhakar R, Nagwani AK, Atul, Mohammed Abdul Al-Nihmi F, Kumar KA, Sijwali PS. Plasmodium DDI1 is a potential therapeutic target and important chromatin-associated protein. Int J Parasitol 2023; 53:157-175. [PMID: 36657610 DOI: 10.1016/j.ijpara.2022.11.007] [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: 07/26/2022] [Revised: 10/13/2022] [Accepted: 11/10/2022] [Indexed: 01/18/2023]
Abstract
DNA damage inducible 1 protein (DDI1) is involved in a variety of cellular processes including proteasomal degradation of specific proteins. All DDI1 proteins contain a ubiquitin-like (UBL) domain and a retroviral protease (RVP) domain. Some DDI1 proteins also contain a ubiquitin-associated (UBA) domain. The three domains confer distinct activities to DDI1 proteins. The presence of a RVP domain makes DDI1 a potential target of HIV protease inhibitors, which also block the development of malaria parasites. Hence, we investigated the DDI1 of malaria parasites to identify its roles during parasite development and potential as a therapeutic target. DDI1 proteins of Plasmodium and other apicomplexan parasites share the UBL-RVP domain architecture, and some also contain the UBA domain. Plasmodium DDI1 is expressed across all the major life cycle stages and is important for parasite survival, as conditional depletion of DDI1 protein in the mouse malaria parasite Plasmodium berghei and the human malaria parasite Plasmodium falciparum compromised parasite development. Infection of mice with DDI1 knock-down P. berghei was self-limiting and protected the recovered mice from subsequent infection with homologous as well as heterologous parasites, indicating the potential of DDI1 knock-down parasites as a whole organism vaccine. Plasmodium falciparum DDI1 (PfDDI1) is associated with chromatin and DNA-protein crosslinks. PfDDI1-depleted parasites accumulated DNA-protein crosslinks and showed enhanced susceptibility to DNA-damaging chemicals, indicating a role of PfDDI1 in removal of DNA-protein crosslinks. Knock-down of PfDDI1 increased susceptibility to the retroviral protease inhibitor lopinavir and antimalarial artemisinin, which suggests that simultaneous inhibition of DDI1 could potentiate antimalarial activity of these drugs. As DDI1 knock-down parasites confer protective immunity and it could be a target of HIV protease inhibitors, Plasmodium DDI1 is a potential therapeutic target for malaria control.
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Affiliation(s)
- Nandita Tanneru
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, TS, India
| | - M Angel Nivya
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, TS, India
| | - Navin Adhikari
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, TS, India
| | - Kanika Saxena
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, TS, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, UP, India
| | - Zeba Rizvi
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, TS, India
| | - Renu Sudhakar
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, TS, India
| | - Amit Kumar Nagwani
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, TS, India
| | - Atul
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, TS, India
| | | | - Kota Arun Kumar
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Puran Singh Sijwali
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, TS, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, UP, India.
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Schwake C, Hyon M, Chishti AH. Signal peptide peptidase: A potential therapeutic target for parasitic and viral infections. Expert Opin Ther Targets 2022; 26:261-273. [PMID: 35235480 DOI: 10.1080/14728222.2022.2047932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Signal peptide peptidase (SPP) is a GxGD-type intramembrane-cleaving aspartyl protease responsible for clearing accumulating signal peptides in the endoplasmic reticulum. SPP is conserved among all kingdoms and is essential for maintaining cell homeostasis. Inhibition of SPP with selective inhibitors and the structurally similar HIV protease inhibitors results in signal peptide accumulation and subsequent cell death. Identification of SPP homologues in major human parasitic infections has opened a new therapeutic opportunity. Moreover, the essentiality of mammalian SPP-mediated viral protein processing during infection is emerging. AREAS COVERED This review introduces the discovery and biological function of human SPP enzymes and identify parasitic homologues as pharmacological targets of both SPP and HIV protease inhibitors. Later, the role of mammalian SPP during viral infection and how disruption of host SPP can be employed as a novel antiviral therapy are examined and discussed. EXPERT OPINION Parasitic and viral infections cause severe health and economic burden, exacerbated by the lack of new therapeutics in the pipeline. SPP has been shown to be essential for malaria parasite growth and encouraging evidence in other parasites demonstrates broad essentiality of these proteases as therapeutic targets. As drug resistant parasite and viruses emerge, SPP inhibition will provide a new generation of compounds to counter the growing threat of antimicrobial resistance.
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Affiliation(s)
- Christopher Schwake
- Department of Developmental, Molecular, and Chemical Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Michael Hyon
- Department of Developmental, Molecular, and Chemical Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Athar H Chishti
- Department of Developmental, Molecular, and Chemical Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
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Shaffer D, Kumwenda J, Chen H, Akelo V, Angira F, Kosgei J, Tonui R, Ssali F, McKhann A, Hogg E, Stewart VA, Murphy SC, Coombs R, Schooley R. Brief Report: No Differences Between Lopinavir/Ritonavir and Nonnucleoside Reverse Transcriptase Inhibitor-Based Antiretroviral Therapy on Clearance of Plasmodium falciparum Subclinical Parasitemia in Adults Living With HIV Starting Treatment (A5297). J Acquir Immune Defic Syndr 2022; 89:178-182. [PMID: 34693933 PMCID: PMC9425486 DOI: 10.1097/qai.0000000000002839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 09/20/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND HIV protease inhibitors anti-Plasmodium falciparum activity in adults remains uncertain. METHODS Adults with HIV CD4+ counts >200 cells/mm3 starting antiretroviral therapy (ART) with P. falciparum subclinical parasitemia (Pf SCP) were randomized 1:1 to (step 1) protease inhibitor lopinavir/ritonavir (LPV/r)-based (arm A) or nonnucleoside reverse transcriptase inhibitor (nNRTI)-based ART (arm B) for 15 days. In step 2, participants received nNRTI-based ART and trimethoprim/sulfamethoxazole prophylaxis for 15 days. P. falciparum SCP clearance was measured by polymerase chain reaction. The Fisher exact test [95% exact confidence interval (CI)] was used to compare proportions of P. falciparum SCP clearance (<10 parasites/μL on 3 occasions within 24 hours) between LPV/r and nNRTI arms at day 15. The Kaplan-Meier method and log-rank test were used to compare time-to-clearance. RESULTS Fifty-two adults from Kenya, Malawi, and Uganda with a median age = 31 (Q1, Q3: 24-39) years, 33% women, with baseline median CD4+ counts of 324 (259-404) cells/mm3, median HIV-1 RNA viremia of 5.18 log10 copies/mL (4.60-5.71), and median estimated P. falciparum density of 454 parasites/μL (83-2219) enrolled in the study. Forty-nine (94%) participants completed the study. At day 15, there was no statistically significant difference in the proportions of P. falciparum SCP clearance between the LPV/r (23.1% clearance; 6 of the 26) and nNRTI (26.9% clearance; 7 of the 26) arms [between-arm difference 3.9% (95% CI, -21.1% to 28.4%; P = 1.00)]. No significant difference in time-to-clearance was observed between the arms (P = 0.80). CONCLUSIONS In a small randomized study of adults starting ART with P. falciparum SCP, no statistically significant differences were seen between LPV/r- and nNRTI-based ART in P. falciparum SCP clearance after 15 days of treatment.
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Affiliation(s)
- Douglas Shaffer
- U.S. Centers for Disease Control and Prevention, Kigali, Rwanda (at time of research)
| | | | - Huichao Chen
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Victor Akelo
- Kenya Medical Research Institute, Center for Global Health (KEMRI/CGHR)/Emory-CDC CTU, Kisumu, Kenya
| | - Francis Angira
- Kenya Medical Research Institute, Center for Global Health (KEMRI/CGHR)/Emory-CDC CTU, Kisumu, Kenya
| | - Josphat Kosgei
- Kenya Medical Research Institute/United States Army Medical Research Directorate-Africa/Kenya, Kericho, Kenya
| | - Ronald Tonui
- Moi University School of Medicine, Eldoret, Kenya
| | | | - Ashley McKhann
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Evelyn Hogg
- Social & Scientific Systems, Inc., A DLH Holdings Company, Silver Spring, MD, USA
| | - V. Ann Stewart
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Sean C. Murphy
- Department of Laboratory Medicine and Pathology, University of Washington; Department of Microbiology, University of Washington; Center for Emerging and Re-emerging Infectious Diseases, University of Washington; Seattle, WA, USA
| | - Robert Coombs
- Department of Laboratory Medicine and Pathology; Department of Medicine, University of Washington, Seattle, WA, USA
| | - Robert Schooley
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
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Repurposing Drugs to Fight Hepatic Malaria Parasites. Molecules 2020; 25:molecules25153409. [PMID: 32731386 PMCID: PMC7435416 DOI: 10.3390/molecules25153409] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/16/2022] Open
Abstract
Malaria remains one of the most prevalent infectious diseases worldwide, primarily affecting some of the most vulnerable populations around the globe. Despite achievements in the treatment of this devastating disease, there is still an urgent need for the discovery of new drugs that tackle infection by Plasmodium parasites. However, de novo drug development is a costly and time-consuming process. An alternative strategy is to evaluate the anti-plasmodial activity of compounds that are already approved for other purposes, an approach known as drug repurposing. Here, we will review efforts to assess the anti-plasmodial activity of existing drugs, with an emphasis on the obligatory and clinically silent liver stage of infection. We will also review the current knowledge on the classes of compounds that might be therapeutically relevant against Plasmodium in the context of other communicable diseases that are prevalent in regions where malaria is endemic. Repositioning existing compounds may constitute a faster solution to the current gap of prophylactic and therapeutic drugs that act on Plasmodium parasites, overall contributing to the global effort of malaria eradication.
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Azevedo R, Mendes AM, Prudêncio M. The Impact of Antiretroviral Therapy on Malaria Parasite Transmission. Front Microbiol 2020; 10:3048. [PMID: 32038528 PMCID: PMC6993566 DOI: 10.3389/fmicb.2019.03048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 12/18/2019] [Indexed: 12/11/2022] Open
Abstract
Coendemicity between the human immunodeficiency virus (HIV) and Plasmodium parasites, the causative agents of acquired immunodeficiency syndrome (AIDS) and malaria, respectively, occurs in several regions around the world. Although the impact of the interaction between these two organisms is not well understood, it is thought that the outcome of either disease may be negatively influenced by coinfection. Therefore, it is important to understand how current first-line antiretroviral therapies (ART) might impact Plasmodium infection in these regions. Here, we describe the effect of 18 antiretroviral compounds and of first-line ART on the blood and sporogonic stages of Plasmodium berghei in vitro and in vivo. We show that the combination zidovudine + lamivudine + lopinavir/ritonavir (LPV/r), employed as first-line HIV treatment in the field, has a strong inhibitory activity on the sporogonic stages of P. berghei and that several non-nucleoside reverse transcriptase inhibitors (NNRTI) have a moderate effect on this stage of the parasite’s life cycle. Our results expose the effect of current first-line ART on Plasmodium infection and identify potential alternative therapies for HIV/AIDS that might impact malaria transmission.
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Affiliation(s)
- Raquel Azevedo
- Faculdade de Medicina, Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal
| | - António M Mendes
- Faculdade de Medicina, Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel Prudêncio
- Faculdade de Medicina, Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal
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Schwake C, Baldwin MR, Bachovchin W, Hegde S, Schiemer J, Okure C, Levin AE, Vannier E, Hanada T, Chishti AH. HIV protease inhibitors block parasite signal peptide peptidases and prevent growth of Babesia microti parasites in erythrocytes. Biochem Biophys Res Commun 2019; 517:125-131. [PMID: 31311649 PMCID: PMC6707064 DOI: 10.1016/j.bbrc.2019.07.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 07/09/2019] [Indexed: 12/11/2022]
Abstract
Malaria and babesiosis are bloodborne protozoan infections for which the emergence of drug-resistant strains poses a threat. Our previous phage display cDNA screens established the essentiality of Plasmodium falciparum signal peptide peptidase (SPP) in asexual development at the blood stage of malaria infection. Given the structural similarities between SPP inhibitors and HIV protease inhibitors, we screened ten HIV protease inhibitors and selected Lopinavir and Atazanavir for their ability to inhibit PfSPP activity. Using a transcription-based assay, we observed that Lopinavir inhibits both parasite-and host-derived SPP activities whereas Atazanavir inhibited only parasite derived SPP activity. Consistent with their inhibitory effect on Plasmodium growth, both Lopinavir and Atazanavir strongly inhibited intraerythrocytic Babesia microti growth ex vivo. Moreover, Lopinavir prevented the steep rise in Babesia microti parasitemia typically observed in rag1-deficient mice. Our data provide first evidence that inhibition of parasite-derived SPPs by HIV protease inhibitors offers a promising therapeutic avenue for the treatment of severe babesiosis and infections caused by other Apicomplexa parasites.
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Affiliation(s)
- Christopher Schwake
- Graduate Program in Cellular, Molecular, and Developmental Biology, USA; Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Michael R Baldwin
- Graduate Program in Cellular and, Molecular Physiology, USA; Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - William Bachovchin
- Graduate Program in Pharmacology and Experimental Therapeutics, USA; Department of Developmental, Molecular and Chemical Biology, USA; Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Shreeya Hegde
- Graduate Program in Pharmacology and Experimental Therapeutics, USA; Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - James Schiemer
- Graduate Program in Cellular and, Molecular Physiology, USA; Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Carolyn Okure
- Graduate Program in Pharmacology and Experimental Therapeutics, USA; Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | | | - Edouard Vannier
- Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, MA, 02111, USA
| | - Toshihiko Hanada
- Department of Developmental, Molecular and Chemical Biology, USA
| | - Athar H Chishti
- Graduate Program in Cellular, Molecular, and Developmental Biology, USA; Graduate Program in Cellular and, Molecular Physiology, USA; Graduate Program in Pharmacology and Experimental Therapeutics, USA; Department of Developmental, Molecular and Chemical Biology, USA; Graduate Program in Molecular Microbiology, USA; Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA.
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Onchieku NM, Mogire R, Ndung'u L, Mwitari P, Kimani F, Matoke-Muhia D, Kiboi D, Magoma G. Deciphering the targets of retroviral protease inhibitors in Plasmodium berghei. PLoS One 2018; 13:e0201556. [PMID: 30067811 PMCID: PMC6070271 DOI: 10.1371/journal.pone.0201556] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 07/17/2018] [Indexed: 11/19/2022] Open
Abstract
Retroviral protease inhibitors (RPIs) such as lopinavir (LP) and saquinavir (SQ) are active against Plasmodium parasites. However, the exact molecular target(s) for these RPIs in the Plasmodium parasites remains poorly understood. We hypothesised that LP and SQ suppress parasite growth through inhibition of aspartyl proteases. Using reverse genetics approach, we embarked on separately generating knockout (KO) parasite lines lacking Plasmepsin 4 (PM4), PM7, PM8, or DNA damage-inducible protein 1 (Ddi1) in the rodent malaria parasite Plasmodium berghei ANKA. We then tested the suppressive profiles of the LP/Ritonavir (LP/RT) and SQ/RT as well as antimalarials; Amodiaquine (AQ) and Piperaquine (PQ) against the KO parasites in the standard 4-day suppressive test. The Ddi1 gene proved refractory to deletion suggesting that the gene is essential for the growth of the asexual blood stage parasites. Our results revealed that deletion of PM4 significantly reduces normal parasite growth rate phenotype (P = 0.003). Unlike PM4_KO parasites which were less susceptible to LP and SQ (P = 0.036, P = 0.030), the suppressive profiles for PM7_KO and PM8_KO parasites were comparable to those for the WT parasites. This finding suggests a potential role of PM4 in the LP and SQ action. On further analysis, modelling and molecular docking studies revealed that both LP and SQ displayed high binding affinities (-6.3 kcal/mol to -10.3 kcal/mol) towards the Plasmodium aspartyl proteases. We concluded that PM4 plays a vital role in assuring asexual stage parasite fitness and might be mediating LP and SQ action. The essential nature of the Ddi1 gene warrants further studies to evaluate its role in the parasite asexual blood stage growth as well as a possible target for the RPIs.
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Affiliation(s)
- Noah Machuki Onchieku
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), Nairobi, Kenya
- Centre for Traditional Medicine and Drug Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Reagan Mogire
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), Nairobi, Kenya
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust, Collaborative Research Program, Kilifi, Kenya
| | - Loise Ndung'u
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), Nairobi, Kenya
| | - Peter Mwitari
- Centre for Traditional Medicine and Drug Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Francis Kimani
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Daniel Kiboi
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust, Collaborative Research Program, Kilifi, Kenya
- West Africa Centre for Cell Biology and Infectious Pathogens, University of Ghana, Accra, Ghana
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Gabriel Magoma
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
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Kwenti TE. Malaria and HIV coinfection in sub-Saharan Africa: prevalence, impact, and treatment strategies. Res Rep Trop Med 2018; 9:123-136. [PMID: 30100779 PMCID: PMC6067790 DOI: 10.2147/rrtm.s154501] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Malaria and HIV, two of the world's most deadly diseases, are widespread, but their distribution overlaps greatly in sub-Saharan Africa. Consequently, malaria and HIV coinfection (MHC) is common in the region. In this paper, pertinent publications on the prevalence, impact, and treatment strategies of MHC obtained by searching major electronic databases (PubMed, PubMed Central, Google Scholar, ScienceDirect, and Scopus) were reviewed, and it was found that the prevalence of MHC in SSA was 0.7%-47.5% overall. Prevalence was 0.7%-47.5% in nonpregnant adults, 1.2%-27.8% in children, and 0.94%-37% in pregnant women. MHC was associated with an increased frequency of clinical parasitemia and severe malaria, increased parasite and viral load, and impaired immunity to malaria in nonpregnant adults, children, and pregnant women, increased in placental malaria and related outcomes in pregnant women, and impaired antimalarial drug efficacy in nonpregnant adults and pregnant women. Although a few cases of adverse events have been reported in coinfected patients receiving antimalarial and antiretroviral drugs concurrently, available data are very limited and have not prompted major revision in treatment guidelines for both diseases. Artemisinin-based combination therapy and cotrimoxazole are currently the recommended drugs for treatment and prevention of malaria in HIV-infected children and adults. However, concurrent administration of cotrimoxazole and sulfadoxine-pyrimethamine in HIV-infected pregnant women is not recommended, because of high risk of sulfonamide toxicity. Further research is needed to enhance our understanding of the impact of malaria on HIV, drug-drug interactions in patients receiving antimalarials and antiretroviral drugs concomitantly, and the development of newer, safer, and more cost-effective drugs and vaccines to prevent malaria in HIV-infected pregnant women.
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Affiliation(s)
- Tebit E Kwenti
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Buea,
- Regional Hospital Buea, Buea, Cameroon,
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10
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Machado M, Sanches-Vaz M, Cruz JP, Mendes AM, Prudêncio M. Inhibition of Plasmodium Hepatic Infection by Antiretroviral Compounds. Front Cell Infect Microbiol 2017; 7:329. [PMID: 28770176 PMCID: PMC5515864 DOI: 10.3389/fcimb.2017.00329] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/03/2017] [Indexed: 11/13/2022] Open
Abstract
Recent WHO guidelines on control of human immunodeficiency virus (HIV) call for the widespread use of antiretroviral (AR) therapy (ART) for people living with HIV. Given the considerable overlap between infections by HIV and Plasmodium, the causative agent of malaria, it is important to understand the impact of AR compounds and ART regimens on infections by malaria parasites. We undertook a systematic approach to identify AR drugs and ART drug combinations with inhibitory activity against the obligatory hepatic stage of Plasmodium infection. Our in vitro screen of a wide array of AR drugs identified the non-nucleoside reverse transcriptase inhibitors efavirenz and etravirine (ETV), and the protease inhibitor nelfinavir, as compounds that significantly impair the development of the rodent malaria parasite P. berghei in an hepatoma cell line. Furthermore, we show that WHO-recommended ART drug combinations currently employed in the field strongly inhibit Plasmodium liver infection in mice, an effect that may be significantly enhanced by the inclusion of ETV in the treatment. Our observations are the first report of ETV as an anti-Plasmodial drug, paving the way for further evaluation and potential use of ETV-containing ARTs in regions of geographical overlap between HIV and Plasmodium infections.
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Affiliation(s)
- Marta Machado
- Faculdade de Medicina, Instituto de Medicina Molecular, Universidade de LisboaLisboa, Portugal
| | - Margarida Sanches-Vaz
- Faculdade de Medicina, Instituto de Medicina Molecular, Universidade de LisboaLisboa, Portugal
| | - João P Cruz
- iMed.UL-Research Institute for Medicines and Pharmaceutical Sciences, Faculdade de Farmácia da Universidade de LisboaLisboa, Portugal
| | - António M Mendes
- Faculdade de Medicina, Instituto de Medicina Molecular, Universidade de LisboaLisboa, Portugal
| | - Miguel Prudêncio
- Faculdade de Medicina, Instituto de Medicina Molecular, Universidade de LisboaLisboa, Portugal
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Hobbs CV, Gabriel EE, Kamthunzi P, Tegha G, Tauzie J, Petzold E, Barlow-Mosha L, Chi BH, Li Y, Ilmet T, Kirmse B, Neal J, Parikh S, Deygoo N, Jean Philippe P, Mofenson L, Prescott W, Chen J, Musoke P, Palumbo P, Duffy PE, Borkowsky W. Malaria in HIV-Infected Children Receiving HIV Protease-Inhibitor- Compared with Non-Nucleoside Reverse Transcriptase Inhibitor-Based Antiretroviral Therapy, IMPAACT P1068s, Substudy to P1060. PLoS One 2016; 11:e0165140. [PMID: 27936233 PMCID: PMC5147802 DOI: 10.1371/journal.pone.0165140] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/05/2016] [Indexed: 11/21/2022] Open
Abstract
Background HIV and malaria geographically overlap. HIV protease inhibitors kill malaria parasites in vitro and in vivo, but further evaluation in clinical studies is needed. Methods Thirty-one children from Malawi aged 4–62 months were followed every 3 months and at intercurrent illness visits for ≤47 months (September 2009-December 2011). We compared malaria parasite carriage by blood smear microscopy (BS) and confirmed clinical malaria incidence (CCM, or positive BS with malaria symptoms) in children initiated on HIV antiretroviral therapy (ART) with zidovudine, lamivudine, and either nevirapine (NVP), a non-nucleoside reverse transcriptase inhibitor, or lopinavir-ritonavir (LPV-rtv), a protease inhibitor. Results We found an association between increased time to recurrent positive BS, but not CCM, when anti-malarial treatment and LPV-rtv based ART were used concurrently and when accounting for a LPV-rtv and antimalarial treatment interaction (adjusted HR 0.39; 95% CI (0.17,0.89); p = 0.03). Conclusions LPV-rtv in combination with malaria treatment was associated with lower risk of recurrent positive BS, but not CCM, in HIV-infected children. Larger, randomized studies are needed to confirm these findings which may permit ART optimization for malaria-endemic settings. Trial Registration ClinicalTrials.gov NCT00719602
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Affiliation(s)
- Charlotte V. Hobbs
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States of America
- Department of Pediatrics, Division of Infectious Disease and Immunology, New York University School of Medicine, NY, United States of America
- Batson Children’s Hospital, Department of Pediatrics (Division of Infectious Diseases) and Department of Microbiology, University of Mississippi Medical Center, Jackson, MS, United States of America
- * E-mail:
| | - Erin E. Gabriel
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Portia Kamthunzi
- Kamuzu Central Hospital, University of North Carolina at Chapel Hill Lilongwe Project, Lilongwe, Malawi
| | - Gerald Tegha
- Kamuzu Central Hospital, University of North Carolina at Chapel Hill Lilongwe Project, Lilongwe, Malawi
| | - Jean Tauzie
- Kamuzu Central Hospital, University of North Carolina at Chapel Hill Lilongwe Project, Lilongwe, Malawi
| | - Elizabeth Petzold
- Duke Clinical Research Institute, Durham, NC, United States of America
| | - Linda Barlow-Mosha
- Makerere University-Johns Hopkins University Research Collaboration, Kampala, Uganda
| | - Benjamin H. Chi
- Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Yonghua Li
- Department of Pediatrics, Division of Infectious Disease and Immunology, New York University School of Medicine, NY, United States of America
| | - Tiina Ilmet
- Department of Pediatrics, Division of Infectious Disease and Immunology, New York University School of Medicine, NY, United States of America
- Cornell Clinical Trials Unit, Weill Cornell Medicine, NY, United States of America
| | - Brian Kirmse
- Department of Pediatrics, Division of Medical Genetics, University of Mississippi Medical Center, Batson Children’s Hospital, Jackson, MS, United States of America
| | - Jillian Neal
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States of America
| | - Sunil Parikh
- Yale Schools of Public Health and Medicine, New Haven, Connecticut, United States of America
| | - Nagamah Deygoo
- Department of Pediatrics, Division of Infectious Disease and Immunology, New York University School of Medicine, NY, United States of America
| | - Patrick Jean Philippe
- HJF-DAIDS, a Division of the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Contractor to NIAID, NIH, DHHS, Bethesda, MD, United States of America
| | - Lynne Mofenson
- Elizabeth Glaser Pediatric AIDS Foundation, Washington, DC, United States of America
| | - William Prescott
- HYDAS World Health, Inc., Hummelstown, PA, United States of America
| | - Jingyang Chen
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States of America
- Ben Towne Center for Childhood Cancer Research, Seattle Children’s Research Institute, the University of Washington, and the Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
| | - Philippa Musoke
- Makerere University-Johns Hopkins University Research Collaboration, Kampala, Uganda
- Department of Pediatrics and Child Health, Makerere University, Kampala, Uganda
| | - Paul Palumbo
- Division of Infectious Diseases and International Health, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States of America
| | - William Borkowsky
- Department of Pediatrics, Division of Infectious Disease and Immunology, New York University School of Medicine, NY, United States of America
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13
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Hobbs CV, Anderson C, Neal J, Sahu T, Conteh S, Voza T, Langhorne J, Borkowsky W, Duffy PE. Trimethoprim-Sulfamethoxazole Prophylaxis During Live Malaria Sporozoite Immunization Induces Long-Lived, Homologous, and Heterologous Protective Immunity Against Sporozoite Challenge. J Infect Dis 2016; 215:122-130. [PMID: 28077589 DOI: 10.1093/infdis/jiw482] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/30/2016] [Indexed: 11/12/2022] Open
Abstract
Trimethoprim-sulfamethoxazole (TMP-SMX) is widely used in malaria-endemic areas in human immunodeficiency virus (HIV)-infected children and HIV-uninfected, HIV-exposed children as opportunistic infection prophylaxis. Despite the known effects that TMP-SMX has in reducing clinical malaria, its impact on development of malaria-specific immunity in these children remains poorly understood. Using rodent malaria models, we previously showed that TMP-SMX, at prophylactic doses, can arrest liver stage development of malaria parasites and speculated that TMP-SMX prophylaxis during repeated malaria exposures would induce protective long-lived sterile immunity targeting pre-erythrocytic stage parasites in mice. Using the same models, we now demonstrate that repeated exposures to malaria parasites during TMP-SMX administration induces stage-specific and long-lived pre-erythrocytic protective anti-malarial immunity, mediated primarily by CD8+ T-cells. Given the HIV infection and malaria coepidemic in sub-Saharan Africa, clinical studies aimed at determining the optimum duration of TMP-SMX prophylaxis in HIV-infected or HIV-exposed children must account for the potential anti-infection immunity effect of TMP-SMX prophylaxis.
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Affiliation(s)
- Charlotte V Hobbs
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland.,Division of Infectious Diseases, Department of Pediatrics.,Department of Microbiology, Batson Children's Hospital, University of Mississippi Medical Center, Jackson.,Division of Infectious Disease and Immunology, Department of Pediatrics, New York University School of Medicine
| | - Charles Anderson
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Jillian Neal
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Tejram Sahu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Solomon Conteh
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Tatiana Voza
- Biological Sciences Department, New York City College of Technology, City University of New York
| | - Jean Langhorne
- Mill Hill Laboratory, Francis Crick Institute, London, United Kingdom
| | - William Borkowsky
- Division of Infectious Disease and Immunology, Department of Pediatrics, New York University School of Medicine
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
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Parikh S, Kajubi R, Huang L, Ssebuliba J, Kiconco S, Gao Q, Li F, Were M, Kakuru A, Achan J, Mwebaza N, Aweeka FT. Antiretroviral Choice for HIV Impacts Antimalarial Exposure and Treatment Outcomes in Ugandan Children. Clin Infect Dis 2016; 63:414-22. [PMID: 27143666 PMCID: PMC4946019 DOI: 10.1093/cid/ciw291] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 04/03/2016] [Indexed: 02/06/2023] Open
Abstract
Pharmacokinetic/pharmacodynamic studies of artemether-lumefantrine and 3 antiretroviral regimens were conducted in malaria-infected Ugandan children. Efavirenz-based treatment was associated with significant reductions in antimalarial exposure and higher risks of recurrent malaria. Caution in their concurrent use is warranted. Background. The optimal treatment of malaria in human immunodeficiency virus (HIV)–infected children requires consideration of critical drug–drug interactions in coinfected children, as these may significantly impact drug exposure and clinical outcomes. Methods. We conducted an intensive and sparse pharmacokinetic/pharmacodynamic study in Uganda of the most widely adopted artemisinin-based combination therapy, artemether-lumefantrine. HIV-infected children on 3 different first-line antiretroviral therapy (ART) regimens were compared to HIV-uninfected children not on ART, all of whom required treatment for Plasmodium falciparum malaria. Pharmacokinetic sampling for artemether, dihydroartemisinin, and lumefantrine exposure was conducted through day 21, and associations between drug exposure and outcomes through day 42 were investigated. Results. One hundred forty-five and 225 children were included in the intensive and sparse pharmacokinetic analyses, respectively. Compared with no ART, efavirenz (EFV) reduced exposure to all antimalarial components by 2.1- to 3.4-fold; lopinavir/ritonavir (LPV/r) increased lumefantrine exposure by 2.1-fold; and nevirapine reduced artemether exposure only. Day 7 concentrations of lumefantrine were 10-fold lower in children on EFV vs LPV/r-based ART, changes that were associated with an approximate 4-fold higher odds of recurrent malaria by day 28 in those on EFV vs LPV/r-based ART. Conclusions. The choice of ART in children living in a malaria-endemic region has highly significant impacts on the pharmacokinetics and pharmacodynamics of artemether-lumefantrine treatment. EFV-based ART reduces all antimalarial components and is associated with the highest risk of recurrent malaria following treatment. For those on EFV, close clinical follow-up for recurrent malaria following artemether-lumefantrine treatment, along with the study of modified dosing regimens that provide higher exposure, is warranted.
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Affiliation(s)
- Sunil Parikh
- Yale School of Public Health, New Haven, Connecticut
| | - Richard Kajubi
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Liusheng Huang
- University of California, San Francisco, and San Francisco General Hospital
| | | | - Sylvia Kiconco
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Qin Gao
- University of California, San Francisco, and San Francisco General Hospital
| | - Fangyong Li
- University of California, San Francisco, and San Francisco General Hospital
| | - Moses Were
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Abel Kakuru
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Jane Achan
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Norah Mwebaza
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Francesca T Aweeka
- University of California, San Francisco, and San Francisco General Hospital
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15
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Liu P, Robbins AH, Marzahn MR, McClung SH, Yowell CA, Stevens SM, Dame JB, Dunn BM. Enzymatic Characterization of Recombinant Food Vacuole Plasmepsin 4 from the Rodent Malaria Parasite Plasmodium berghei. PLoS One 2015; 10:e0141758. [PMID: 26510189 PMCID: PMC4624963 DOI: 10.1371/journal.pone.0141758] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 10/12/2015] [Indexed: 01/17/2023] Open
Abstract
The rodent malaria parasite Plasmodium berghei is a practical model organism for experimental studies of human malaria. Plasmepsins are a class of aspartic proteinase isoforms that exert multiple pathological effects in malaria parasites. Plasmepsins residing in the food vacuole (FV) of the parasite hydrolyze hemoglobin in red blood cells. In this study, we cloned PbPM4, the FV plasmepsin gene of P. berghei that encoded an N-terminally truncated pro-segment and the mature enzyme from genomic DNA. We over-expressed this PbPM4 zymogen as inclusion bodies (IB) in Escherichia coli, and purified the protein following in vitro IB refolding. Auto-maturation of the PbPM4 zymogen to mature enzyme was carried out at pH 4.5, 5.0, and 5.5. Interestingly, we found that the PbPM4 zymogen exhibited catalytic activity regardless of the presence of the pro-segment. We determined the optimal catalytic conditions for PbPM4 and studied enzyme kinetics on substrates and inhibitors of aspartic proteinases. Using combinatorial chemistry-based peptide libraries, we studied the active site preferences of PbPM4 at subsites S1, S2, S3, S1’, S2’ and S3’. Based on these results, we designed and synthesized a selective peptidomimetic compound and tested its inhibition of PbPM4, seven FV plasmepsins from human malaria parasites, and human cathepsin D (hcatD). We showed that this compound exhibited a >10-fold selectivity to PbPM4 and human malaria parasite plasmepsin 4 orthologs versus hcatD. Data from this study furthesr our understanding of enzymatic characteristics of the plasmepsin family and provides leads for anti-malarial drug design.
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Affiliation(s)
- Peng Liu
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, Florida, United States of America
- * E-mail: (PL); (BMD)
| | - Arthur H. Robbins
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, Florida, United States of America
| | - Melissa R. Marzahn
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, Florida, United States of America
| | - Scott H. McClung
- Protein Core, Interdisciplinary Center for Biotechnology Research, University of Florida, College of Medicine, Gainesville, Florida, United States of America
| | - Charles A. Yowell
- Department of Infectious Diseases and Pathology, University of Florida, College of Veterinary Medicine, Gainesville, Florida, United States of America
| | - Stanley M. Stevens
- Protein Core, Interdisciplinary Center for Biotechnology Research, University of Florida, College of Medicine, Gainesville, Florida, United States of America
| | - John B. Dame
- Department of Infectious Diseases and Pathology, University of Florida, College of Veterinary Medicine, Gainesville, Florida, United States of America
| | - Ben M. Dunn
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, Florida, United States of America
- * E-mail: (PL); (BMD)
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The Glucose Transporter PfHT1 Is an Antimalarial Target of the HIV Protease Inhibitor Lopinavir. Antimicrob Agents Chemother 2015; 59:6203-9. [PMID: 26248369 DOI: 10.1128/aac.00899-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 07/17/2015] [Indexed: 01/08/2023] Open
Abstract
Malaria and HIV infection are coendemic in a large portion of the world and remain a major cause of morbidity and mortality. Growing resistance of Plasmodium species to existing therapies has increased the need for new therapeutic approaches. The Plasmodium glucose transporter PfHT is known to be essential for parasite growth and survival. We have previously shown that HIV protease inhibitors (PIs) act as antagonists of mammalian glucose transporters. While the PI lopinavir is known to have antimalarial activity, the mechanism of action is unknown. We report here that lopinavir blocks glucose uptake into isolated malaria parasites at therapeutically relevant drug levels. Malaria parasites depend on a constant supply of glucose as their primary source of energy, and decreasing the available concentration of glucose leads to parasite death. We identified the malarial glucose transporter PfHT as a target for inhibition by lopinavir that leads to parasite death. This discovery provides a mechanistic basis for the antimalarial effect of lopinavir and provides a direct target for novel drug design with utility beyond the HIV-infected population.
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17
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Qin L, Qin L, Xu W, Zhao S, Chen X. Ritonavir-boosted indinavir but not lopinavir inhibits erythrocytic stage Plasmodium knowlesi malaria in rhesus macaques. Bioorg Med Chem Lett 2015; 25:1538-40. [PMID: 25704890 DOI: 10.1016/j.bmcl.2015.02.014] [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: 01/07/2015] [Revised: 02/02/2015] [Accepted: 02/07/2015] [Indexed: 11/28/2022]
Abstract
The inhibitive activities of the human immunodeficiency virus protease inhibitors ritonavir (RTV) boosted indinavir (IDV) and RTV boosted lopinavir (LPV) for erythrocytic stage malaria were evaluated in rhesus macaques. The IDV/RTV regimen effectively inhibits the replication of Plasmodium knowlesi with clinically relevant doses, whereas the LPV/RTV regimen did not show activity against plasmodium infection.
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Affiliation(s)
- Li Qin
- Laboratory of Pathogen Biology, State Key Laboratory of Respiratory Disease, Center for Infection and Immunity, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, No. 190, Kaiyuan Avenue, Guangzhou Science Park, Guangzhou 510530, China
| | - Limei Qin
- Laboratory of Pathogen Biology, State Key Laboratory of Respiratory Disease, Center for Infection and Immunity, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, No. 190, Kaiyuan Avenue, Guangzhou Science Park, Guangzhou 510530, China
| | - Wanwan Xu
- Laboratory of Pathogen Biology, State Key Laboratory of Respiratory Disease, Center for Infection and Immunity, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, No. 190, Kaiyuan Avenue, Guangzhou Science Park, Guangzhou 510530, China
| | - Siting Zhao
- Laboratory of Pathogen Biology, State Key Laboratory of Respiratory Disease, Center for Infection and Immunity, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, No. 190, Kaiyuan Avenue, Guangzhou Science Park, Guangzhou 510530, China
| | - Xiaoping Chen
- Laboratory of Pathogen Biology, State Key Laboratory of Respiratory Disease, Center for Infection and Immunity, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, No. 190, Kaiyuan Avenue, Guangzhou Science Park, Guangzhou 510530, China.
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18
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Comparative genomic analysis of aspartic proteases in eight parasitic platyhelminths: Insights into functions and evolution. Gene 2015; 559:52-61. [DOI: 10.1016/j.gene.2015.01.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/08/2015] [Accepted: 01/09/2015] [Indexed: 01/05/2023]
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Hobbs CV, Dixit S, Penzak SR, Sahu T, Orr-Gonzalez S, Lambert L, Zeleski K, Chen J, Neal J, Borkowsky W, Wu Y, Duffy PE. Neither the HIV protease inhibitor lopinavir-ritonavir nor the antimicrobial trimethoprim-sulfamethoxazole prevent malaria relapse in plasmodium cynomolgi-infected non-human primates. PLoS One 2014; 9:e115506. [PMID: 25541998 PMCID: PMC4277318 DOI: 10.1371/journal.pone.0115506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 11/24/2014] [Indexed: 12/20/2022] Open
Abstract
Plasmodium vivax malaria causes significant morbidity and mortality worldwide, and only one drug is in clinical use that can kill the hypnozoites that cause P. vivax relapses. HIV and P. vivax malaria geographically overlap in many areas of the world, including South America and Asia. Despite the increasing body of knowledge regarding HIV protease inhibitors (HIV PIs) on P. falciparum malaria, there are no data regarding the effects of these treatments on P. vivax's hypnozoite form and clinical relapses of malaria. We have previously shown that the HIV protease inhibitor lopinavir-ritonavir (LPV-RTV) and the antibiotic trimethoprim sulfamethoxazole (TMP-SMX) inhibit Plasmodium actively dividing liver stages in rodent malarias and in vitro in P. falciparum, but effect against Plasmodium dormant hypnozoite forms remains untested. Separately, although other antifolates have been tested against hypnozoites, the antibiotic trimethoprim sulfamethoxazole, commonly used in HIV infection and exposure management, has not been evaluated for hypnozoite-killing activity. Since Plasmodium cynomolgi is an established animal model for the study of liver stages of malaria as a surrogate for P. vivax infection, we investigated the antimalarial activity of these drugs on Plasmodium cynomolgi relapsing malaria in rhesus macaques. Herein, we demonstrate that neither TMP-SMX nor LPV-RTV kills hypnozoite parasite liver stage forms at the doses tested. Because HIV and malaria geographically overlap, and more patients are being managed for HIV infection and exposure, understanding HIV drug impact on malaria infection is important.
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Affiliation(s)
- Charlotte V. Hobbs
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail:
| | - Saurabh Dixit
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Scott R. Penzak
- Department of Pharmacotherapy, University of North Texas System College of Pharmacy, Fort Worth, Texas, 76107, United States of America
| | - Tejram Sahu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Sachy Orr-Gonzalez
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Lynn Lambert
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Katie Zeleski
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Jingyang Chen
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Jillian Neal
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - William Borkowsky
- Department of Pediatrics, Division of Infectious Disease and Immunology, New York University School of Medicine, New York, New York, United States of America
| | - Yimin Wu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
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Lerdsirisuk P, Maicheen C, Ungwitayatorn J. Antimalarial activity of HIV-1 protease inhibitor in chromone series. Bioorg Chem 2014; 57:142-147. [PMID: 25462990 DOI: 10.1016/j.bioorg.2014.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/24/2014] [Accepted: 10/28/2014] [Indexed: 10/24/2022]
Abstract
Increasing parasite resistance to nearly all available antimalarial drugs becomes a serious problem to human health and necessitates the need to continue the search for new effective drugs. Recent studies have shown that clinically utilized HIV-1 protease (HIV-1 PR) inhibitors can inhibit the in vitro and in vivo growth of Plasmodium falciparum. In this study, a series of chromone derivatives possessing HIV-1 PR inhibitory activity has been tested for antimalarial activity against P. falciparum (K1 multi-drug resistant strain). Chromone 15, the potent HIV-1 PR inhibitor (IC50=0.65μM), was found to be the most potent antimalarial compound with IC50=0.95μM while primaquine and tafenoquine showed IC50=2.41 and 1.95μM, respectively. Molecular docking study of chromone compounds against plasmepsin II, an aspartic protease enzyme important in hemoglobin degradation, revealed that chromone 15 exhibited the higher binding affinity (binding energy=-13.24kcal/mol) than the known PM II inhibitors. Thus, HIV-1 PR inhibitor in chromone series has the potential to be a new class of antimalarial agent.
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Affiliation(s)
| | - Chirattikan Maicheen
- Center of Excellence for Innovation in Drug Design and Discovery, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudhya Road, Bangkok 10400, Thailand
| | - Jiraporn Ungwitayatorn
- Center of Excellence for Innovation in Drug Design and Discovery, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudhya Road, Bangkok 10400, Thailand.
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21
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Hobbs CV, Neal J, Conteh S, Donnelly L, Chen J, Marsh K, Lambert L, Orr-Gonzalez S, Hinderer J, Healy S, Borkowsky W, Penzak SR, Chakravarty S, Hoffman SL, Duffy PE. HIV treatments reduce malaria liver stage burden in a non-human primate model of malaria infection at clinically relevant concentrations in vivo. PLoS One 2014; 9:e100138. [PMID: 24988386 PMCID: PMC4079689 DOI: 10.1371/journal.pone.0100138] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 05/21/2014] [Indexed: 11/18/2022] Open
Abstract
We have previously shown that the HIV protease inhibitor lopinavir-ritonavir (LPV-RTV) and the antibiotic trimethoprim sulfamethoxazole (TMP-SMX) inhibit Plasmodium liver stages in rodent malarias and in vitro in P. falciparum. Since clinically relevant levels are better achieved in the non-human-primate model, and since Plasmodium knowlesi is an accepted animal model for the study of liver stages of malaria as a surrogate for P. falciparum infection, we investigated the antimalarial activity of these drugs on Plasmodium knowlesi liver stages in rhesus macaques. We demonstrate that TMP-SMX and TMP-SMX+LPV-RTV (in combination), but not LPV-RTV alone, inhibit liver stage parasite development. Because drugs that inhibit the clinically silent liver stages target parasites when they are present in lower numbers, these results may have implications for eradication efforts.
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Affiliation(s)
- Charlotte V. Hobbs
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
- * E-mail:
| | - Jillian Neal
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | - Solomon Conteh
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | - Liam Donnelly
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | - Jingyang Chen
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | - Kennan Marsh
- AbbVie Inc., North Chicago, Illinois, United States of America
| | - Lynn Lambert
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | - Sachy Orr-Gonzalez
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | - Jessica Hinderer
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | - Sara Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | - William Borkowsky
- Division of Infectious Disease and Immunology, Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
| | - Scott R. Penzak
- Clinical Center Pharmacy Department, Clinical Pharmacokinetics Research Laboratory, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | | | | | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health/National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
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Spottiswoode N, Duffy PE, Drakesmith H. Iron, anemia and hepcidin in malaria. Front Pharmacol 2014; 5:125. [PMID: 24910614 PMCID: PMC4039013 DOI: 10.3389/fphar.2014.00125] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 05/11/2014] [Indexed: 12/21/2022] Open
Abstract
Malaria and iron have a complex but important relationship. Plasmodium proliferation requires iron, both during the clinically silent liver stage of growth and in the disease-associated phase of erythrocyte infection. Precisely how the protozoan acquires its iron from its mammalian host remains unclear, but iron chelators can inhibit pathogen growth in vitro and in animal models. In humans, iron deficiency appears to protect against severe malaria, while iron supplementation increases risks of infection and disease. Malaria itself causes profound disturbances in physiological iron distribution and utilization, through mechanisms that include hemolysis, release of heme, dyserythropoiesis, anemia, deposition of iron in macrophages, and inhibition of dietary iron absorption. These effects have significant consequences. Malarial anemia is a major global health problem, especially in children, that remains incompletely understood and is not straightforward to treat. Furthermore, the changes in iron metabolism during a malaria infection may modulate susceptibility to co-infections. The release of heme and accumulation of iron in granulocytes may explain increased vulnerability to non-typhoidal Salmonella during malaria. The redistribution of iron away from hepatocytes and into macrophages may confer host resistance to superinfection, whereby blood-stage parasitemia prevents the development of a second liver-stage Plasmodium infection in the same organism. Key to understanding the pathophysiology of iron metabolism in malaria is the activity of the iron regulatory hormone hepcidin. Hepcidin is upregulated during blood-stage parasitemia and likely mediates much of the iron redistribution that accompanies disease. Understanding the regulation and role of hepcidin may offer new opportunities to combat malaria and formulate better approaches to treat anemia in the developing world.
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Affiliation(s)
- Natasha Spottiswoode
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesda, MD, USA
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of OxfordOxford, UK
| | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesda, MD, USA
| | - Hal Drakesmith
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of OxfordOxford, UK
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Abstract
Drugs that kill or inhibit the sexual stages of Plasmodium in order to prevent transmission are important components of malaria control programmes. Reducing gametocyte carriage is central to the control of Plasmodium falciparum transmission as infection can result in extended periods of gametocytaemia. Unfortunately the number of drugs with activity against gametocytes is limited. Primaquine is currently the only licensed drug with activity against the sexual stages of malaria parasites and its use is hampered by safety concerns. This shortcoming is likely the result of the technical challenges associated with gametocyte studies together with the focus of previous drug discovery campaigns on asexual parasite stages. However recent emphasis on malaria eradication has resulted in an upsurge of interest in identifying compounds with activity against gametocytes. This review examines the gametocytocidal properties of currently available drugs as well as those in the development pipeline and examines the prospects for discovery of new anti-gametocyte compounds.
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Torins are potent antimalarials that block replenishment of Plasmodium liver stage parasitophorous vacuole membrane proteins. Proc Natl Acad Sci U S A 2013; 110:E2838-47. [PMID: 23836641 DOI: 10.1073/pnas.1306097110] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Residence within a customized vacuole is a highly successful strategy used by diverse intracellular microorganisms. The parasitophorous vacuole membrane (PVM) is the critical interface between Plasmodium parasites and their possibly hostile, yet ultimately sustaining, host cell environment. We show that torins, developed as ATP-competitive mammalian target of rapamycin (mTOR) kinase inhibitors, are fast-acting antiplasmodial compounds that unexpectedly target the parasite directly, blocking the dynamic trafficking of the Plasmodium proteins exported protein 1 (EXP1) and upregulated in sporozoites 4 (UIS4) to the liver stage PVM and leading to efficient parasite elimination by the hepatocyte. Torin2 has single-digit, or lower, nanomolar potency in both liver and blood stages of infection in vitro and is likewise effective against both stages in vivo, with a single oral dose sufficient to clear liver stage infection. Parasite elimination and perturbed trafficking of liver stage PVM-resident proteins are both specific aspects of torin-mediated Plasmodium liver stage inhibition, indicating that torins have a distinct mode of action compared with currently used antimalarials.
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Abstract
HIV and malaria overlap geographically, but the full impact of different antiretrovirals on malaria remains poorly understood. We examined the antimalarial activity of the HIV protease inhibitors lopinavir and saquinavir and the non-nucleoside reverse transcriptase inhibitor nevirapine on Plasmodium falciparum liver stages. Our results demonstrate that the HIV PI lopinavir inhibits liver stage parasites at clinically relevant concentrations, that is, at drug levels achieved in HIV-infected patients on standard dosing regimens. Because drugs that inhibit liver stages target parasites when they are present in lower numbers, these results might have implications for eradication efforts.
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Hobbs CV, Tanaka TQ, Muratova O, Van Vliet J, Borkowsky W, Williamson KC, Duffy PE. HIV treatments have malaria gametocyte killing and transmission blocking activity. J Infect Dis 2013; 208:139-48. [PMID: 23539746 DOI: 10.1093/infdis/jit132] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Millions of individuals being treated for human immunodeficiency virus (HIV) live in malaria-endemic areas, but the effects of these treatments on malaria transmission are unknown. While drugs like HIV protease inhibitors (PIs) and trimethoprim-sulfamethoxazole (TMP-SMX) have known activity against parasites during liver or asexual blood stages, their effects on transmission stages require further study. METHODS The HIV PIs lopinavir and saquinavir, the nonnucleoside reverse-transcriptase inhibitor nevirapine, and the antibiotic TMP-SMX were assessed for activity against Plasmodium falciparum transmission stages. The alamarBlue assay was used to determine the effects of drugs on gametocyte viability, and exflagellation was assessed to determine the effects of drugs on gametocyte maturation. The effects of drug on transmission were assessed by calculating the mosquito oocyst count as a marker for infectivity, using standard membrane feeding assays. RESULTS Lopinavir and saquinavir have gametocytocidal and transmission blocking activities at or approaching clinically relevant treatment levels, while nevirapine does not. TMP-SMX is not gametocytocidal, but at prophylactic levels it blocks transmission. CONCLUSIONS Specific HIV treatments have gametocyte killing and transmission-blocking effects. Clinical studies are warranted to evaluate these findings and their potential impact on eradication efforts.
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Affiliation(s)
- Charlotte V Hobbs
- Laboratory of Malaria Vaccinology and Immunology, NIH/NIAID, 12735 Twinbrook Pkwy, Rockville, MD 20852, USA.
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27
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Hobbs CV, Voza T, De La Vega P, Vanvliet J, Conteh S, Penzak SR, Fay MP, Anders N, Ilmet T, Li Y, Borkowsky W, Krzych U, Duffy PE, Sinnis P. HIV nonnucleoside reverse transcriptase inhibitors and trimethoprim-sulfamethoxazole inhibit plasmodium liver stages. J Infect Dis 2013; 206:1706-14. [PMID: 23125449 DOI: 10.1093/infdis/jis602] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Although nonnucleoside reverse transcriptase inhibitors (NNRTIs) are usually part of first-line treatment regimens for human immunodeficiency virus (HIV), their activity on Plasmodium liver stages remains unexplored. Additionally, trimethoprim-sulfamethoxazole (TMP-SMX), used for opportunistic infection prophylaxis in HIV-exposed infants and HIV-infected patients, reduces clinical episodes of malaria; however, TMP-SMX effect on Plasmodium liver stages requires further study. METHODS We characterized NNRTI and TMP-SMX effects on Plasmodium liver stages in vivo using Plasmodium yoelii. On the basis of these results, we conducted in vitro studies assessing TMP-SMX effects on the rodent parasites P. yoelii and Plasmodium berghei and on the human malaria parasite Plasmodium falciparum. RESULTS Our data showed NNRTI treatment modestly reduced P. yoelii liver stage parasite burden and minimally extended prepatent period. TMP-SMX administration significantly reduced liver stage parasite burden, preventing development of patent parasitemia in vivo. TMP-SMX inhibited development of rodent and P. falciparum liver stage parasites in vitro. CONCLUSIONS NNRTIs modestly affect liver stage Plasmodium parasites, whereas TMP-SMX prevents patent parasitemia. Because drugs that inhibit liver stages target parasites when they are present in lower numbers, these results may have implications for eradication efforts. Understanding HIV drug effects on Plasmodium liver stages will aid in optimizing treatment regimens for HIV-exposed and HIV-infected infected patients in malaria-endemic areas.
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Affiliation(s)
- Charlotte V Hobbs
- NIH/NIAID/Laboratory of Malaria Immunology and Vaccinology, Rockville, Maryland 20852, USA
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Saracino A, Nacarapa EA, da Costa Massinga ÉA, Martinelli D, Scacchetti M, de Oliveira C, Antonich A, Galloni D, Ferro JJ, Macome CA. Prevalence and clinical features of HIV and malaria co-infection in hospitalized adults in Beira, Mozambique. Malar J 2012; 11:241. [PMID: 22835018 PMCID: PMC3439710 DOI: 10.1186/1475-2875-11-241] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 07/12/2012] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Mozambique presents a very high prevalence of both malaria and HIV infection, but the impact of co-cancel infection on morbidity in this population has been rarely investigated. The aim of this study was to describe the prevalence and clinical characteristics of malaria in hospitalized adult HIV-positive patients, treated and untreated with combination anti-retroviral therapy (ART) and cotrimoxazole (CTX)-based chemoprophylaxis, compared to HIV negatives. METHODS From November to December 2010, all adult patients consecutively admitted to the Department of Internal Medicine of Beira Central Hospital, Sofala Province, Mozambique, were submitted to HIV testing, malaria blood smear (MBS) and, in a subgroup of patients, also to the rapid malaria test (RDT). Socio-demographical and clinical data were collected for all patients. The association of both a positive MBS and/or RDT and diagnosis of clinical malaria with concomitant HIV infection (and use of CTX and/or ART) was assessed statistically. Frequency of symptoms and hematological alterations in HIV patients with clinical malaria compared to HIV negatives was also analysed. Sensitivity and specificity for RDT versus MBS were calculated for both HIV-positive and negative patients. RESULTS A total of 330 patients with available HIV test and MBS were included in the analysis, 220 of whom (66.7%) were HIV-positive. In 93 patients, malaria infection was documented by MBS and/or RDT. RDT sensitivity and specificity were 94% and 96%, respectively. According to laboratory results, the initial malaria suspicion was discarded in about 10% of cases, with no differences between HIV-positive and negative patients. A lower malaria risk was significantly associated with CTX prophylaxis (p=0.02), but not with ART based on non nucleoside reverse-transcriptase inhibitors (NNRTIs). Overall, severe malaria seemed to be more common in HIV-positive patients (61.7%) compared to HIV-negatives (47.2%), while a significantly lower haemoglobin level was observed in the group of HIV-positive patients (9.9 ± 2.8 mg/dl) compared to those HIV-negative (12.1 ± 2.8 mg/dl) (p=0.003). CONCLUSIONS Malaria infection was rare in HIV-positive individuals treated with CTX for opportunistic infections, while no independent anti-malarial effect for NNRTIs was noted. When HIV and malaria co-infection occurred, a high risk of complications, particularly anaemia, should be expected.
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Affiliation(s)
- Annalisa Saracino
- Doctors with Africa CUAMM-Mozambique, Beira, Mozambique
- Clinic of Infectious Diseases, University of Foggia, v.le L. Pinto 1, Foggia, 71100, Italy
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29
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González R, Ataíde R, Naniche D, Menéndez C, Mayor A. HIV and malaria interactions: where do we stand? Expert Rev Anti Infect Ther 2012; 10:153-65. [PMID: 22339190 DOI: 10.1586/eri.11.167] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Reversing the spread of HIV infection and the incidence of malaria constitute two of the Millenium Development Goals. However, despite recent achievements, both diseases still entail global heath problems. Furthermore, their overlapping geographical distribution raises concerns and challenges for potential immunological, clinical and therapeutic interactions. It has been reported that HIV infection increases malaria susceptibility and reduces the efficacy of antimalarial drugs. On the other hand, the effect of malaria on HIV-infected individuals has also been explored, with the parasitic infection increasing the risk of HIV disease progression and mother-to-child transmission of HIV. The spread of malaria and parasite resistance to antimalarials could also be accelerated by HIV-associated immunosuppresion. Current knowledge of the epidemiological, clinical, immunological and therapeutic interactions of the two diseases is reviewed in this article. We focus on the latest available data, pointing out key future research areas and challenges of the field.
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Affiliation(s)
- Raquel González
- Barcelona Centre for International Heath Research (CRESIB), Hospital Clínic/IDIBAPS, Universitat de Barcelona, Spain
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30
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Unresolved antiretroviral treatment management issues in HIV-infected children. J Acquir Immune Defic Syndr 2012; 59:161-9. [PMID: 22138766 DOI: 10.1097/qai.0b013e3182427029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Antiretroviral therapy in children has expanded dramatically in low-income and middle-income countries. The World Health Organization revised its pediatric HIV guidelines to recommend initiation of antiretroviral therapy in all HIV-infected children younger than 2 years, regardless of CD4 count or clinical stage. The number of children starting life-long antiretroviral therapy should therefore expand dramatically over time. The early initiation of antiretroviral therapy has indisputable benefits for children, but there is a paucity of definitive information on the potential adverse effects. In this review, a comprehensive literature search was conducted to provide an overview of our knowledge about the complications of treating pediatric HIV. Antiretroviral therapy in children, as in adults, is associated with enhanced survival, reduction in opportunistic infections, improved growth and neurocognitive function, and better quality of life. Despite antiretroviral therapy, HIV-infected children may continue to lag behind their uninfected peers in growth and development. In addition, epidemic concurrent conditions, such as tuberculosis, malaria, and malnutrition, can combine with HIV to yield more rapid disease progression and poor treatment outcomes. Additional studies are required to evaluate the long-term effects of antiretroviral therapy in HIV-infected infants, children, and adolescents, particularly in resource-limited countries where concomitant infections and conditions may enhance the risk of adverse effects. There is an urgent need to evaluate drug-drug interactions in children to determine optimal treatment regimens for both HIV and coinfections.
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Abstract
The emergence and spread of drug resistance in the malaria parasite Plasmodium falciparum as well as multi- and extremely drug-resistant forms of Mycobacterium tuberculosis, the causative agent of TB, could hamper the control of these diseases. For instance, there are indications that the malaria parasite is becoming resistant to artemisinin derivatives, drugs that form the backbone of antimalarial combination therapy. Likewise, Mycobacterium tuberculosis strains that are multidrug-resistant or extremely drug-resistant to first- and second-line drugs have been associated with increased mortality. Thus, more than ever, new antimalarials and anti-TB drugs are needed. One of the strategies to discover new drugs is to reposition or repurpose existing drugs, thus reducing the cost and time of drug development. In this review, we discuss how this concept has been used in the past to discover antimalarial and anti-TB drugs, and summarize strategies that can lead to the discovery and development of new drugs.
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32
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Quantification of sporozoite invasion, migration, and development by microscopy and flow cytometry. Methods Mol Biol 2012; 923:385-400. [PMID: 22990793 DOI: 10.1007/978-1-62703-026-7_27] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
There is an important role for in vitro assays to better understand the initial steps of malaria infection. In this section, we describe both microscopy-based and flow cytometry-based sporozoite invasion, migration and development assays with the rodent malaria parasites, Plasmodium berghei and Plasmodium yoelii, and the human malaria parasite, Plasmodium falciparum.
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33
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Annoura T, Chevalley S, Janse CJ, Franke-Fayard B, Khan SM. Quantitative analysis of Plasmodium berghei liver stages by bioluminescence imaging. Methods Mol Biol 2012; 923:429-43. [PMID: 22990796 DOI: 10.1007/978-1-62703-026-7_30] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We describe simple and sensitive in vitro and in vivo assays to analyze Plasmodium liver stage development using transgenic P. berghei parasites (PbGFP-Luccon), which express the bioluminescent reporter protein, luciferase. In these assays, parasite development in hepatocytes is visualized and quantified by real-time bioluminescence imaging both in culture and in live mice. We also describe quantification of in vitro liver-stage development by measuring luminescence using a microplate reader. Reporter-parasite based quantification of liver-stage development is faster and correlates very well with established quantitative RT-PCR methods currently used to assess parasite development inside hepatocytes, both in live mice and in culture.
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Affiliation(s)
- Takeshi Annoura
- Center of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
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34
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Rodrigues T, Prudêncio M, Moreira R, Mota MM, Lopes F. Targeting the liver stage of malaria parasites: a yet unmet goal. J Med Chem 2011; 55:995-1012. [PMID: 22122518 DOI: 10.1021/jm201095h] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tiago Rodrigues
- Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-019 Lisbon, Portugal
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HIV-1 protease inhibitors and clinical malaria: a secondary analysis of the AIDS Clinical Trials Group A5208 study. Antimicrob Agents Chemother 2011; 56:995-1000. [PMID: 22123685 DOI: 10.1128/aac.05322-11] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 protease inhibitors (PIs) have antimalarial activity in vitro and in murine models. The potential beneficial effect of HIV-1 PIs on malaria has not been studied in clinical settings. We used data from Adult AIDS Clinical Trials Group A5208 sites where malaria is endemic to compare the incidence of clinically diagnosed malaria among HIV-infected adult women randomized to either lopinavir/ritonavir (LPV/r)-based antiretroviral therapy (ART) or to nevirapine (NVP)-based ART. We calculated hazard ratios and 95% confidence intervals. We conducted a recurrent events analysis that included both first and second clinical malarial episodes and also conducted analyses to assess the sensitivity of results to outcome misclassification. Among the 445 women in this analysis, 137 (31%) received a clinical diagnosis of malaria at least once during follow-up. Of these 137, 72 (53%) were randomized to LPV/r-based ART. Assignment to the LPV/r treatment group (n = 226) was not consistent with a large decrease in the hazard of first clinical malarial episode (hazard ratio = 1.11 [0.79 to 1.56]). The results were similar in the recurrent events analysis. Sensitivity analyses indicated the results were robust to reasonable levels of outcome misclassification. In this study, the treatment with LPV/r compared to NVP had no apparent beneficial effect on the incidence of clinical malaria among HIV-infected adult women. Additional research concerning the effects of PI-based therapy on the incidence of malaria diagnosed by more specific criteria and among groups at a higher risk for severe disease is warranted.
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Hobbs C, Duffy P. Drugs for malaria: something old, something new, something borrowed. F1000 BIOLOGY REPORTS 2011; 3:24. [PMID: 22076126 PMCID: PMC3206709 DOI: 10.3410/b3-24] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Malaria was estimated to cause 800,000 deaths and 225 million cases worldwide in 2010. Worryingly, the first-line treatment currently relies on a single drug class called artemisinins, and there are signs that the parasite is becoming resistant to these drugs. The good news is that new technology has given us new approaches to drug discovery. New drugs generated this way are probably 10-15 years away from the clinic. Other antimalarials that may offer hope include those rehabilitated after not being used for some time, those that act as inhibitors of resistance mechanisms, those that limit infection while allowing protective immunity to develop, and those which are drugs borrowed from other disease treatments. All of these offer new hope of turning the tables on malaria. In parallel with the effort to develop vaccines that interrupt malaria transmission, drugs that target the parasite during transmission to the mosquito or during its pre-erythrocytic development in the liver, may allow us to terminate the parasite's spread.
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Affiliation(s)
- Charlotte Hobbs
- NIH/NIAID, Laboratory of Malaria Immunology and Vaccinology12735 Twinbrook Parkway, 3W19E, Rockville, MD 20852USA
| | - Patrick Duffy
- NIH/NIAID, Laboratory of Malaria Immunology and Vaccinology, Division of Intramural Research5640 Fishers Lane, Rm. 1111 Rockville, MD 20892USA
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Flateau C, Le Loup G, Pialoux G. Consequences of HIV infection on malaria and therapeutic implications: a systematic review. THE LANCET. INFECTIOUS DISEASES 2011; 11:541-56. [PMID: 21700241 DOI: 10.1016/s1473-3099(11)70031-7] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Despite recent changes in the epidemiology of HIV infection and malaria and major improvements in their control, these diseases remain two of the most important infectious diseases and global health priorities. As they have overlapping distribution in tropical areas, particularly sub-Saharan Africa, any of their clinical, diagnostic, and therapeutic interactions might have important effects on patient care and public health policy. The biological basis of these interactions is well established. HIV infection induces cellular depletion and early abnormalities of CD4+ T cells, decreases CD8+ T-cell counts and function (cellular immunity), causes deterioration of specific antigen responses (humoral immunity), and leads to alteration of innate immunity through impairment of cytolytic activity and cytokine production by natural killer cells. Therefore, HIV infection affects the immune response to malaria, particularly premunition in adolescents and adults, and pregnancy-specific immunity, leading to different patterns of disease in HIV-infected patients compared with HIV-uninfected patients. In this systematic review, we collate data on the effects of HIV on malaria and discuss their therapeutic consequences. HIV infection is associated with increased prevalence and severity of clinical malaria and impaired response to antimalarial treatment, depending on age, immunodepression, and previous immunity to malaria. HIV also affects pregnancy-specific immunity to malaria and response to intermittent preventive treatment. Co-trimoxazole (trimethoprim-sulfamethoxazole) prophylaxis and antiretroviral treatment reduce occurrence of clinical malaria; however, these therapies interact with antimalarial drugs, and new therapeutic guidelines are needed for concomitant use.
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Affiliation(s)
- Clara Flateau
- Service des Maladies Infectieuses et Tropicales, Hôpital Tenon, AP-HP, University Pierre et Marie Curie, Paris, France
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38
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Antimalarial effects of human immunodeficiency virus protease inhibitors in rhesus macaques. Antimicrob Agents Chemother 2011; 55:3039-42. [PMID: 21486958 DOI: 10.1128/aac.00085-11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The antimalarial activity of the human immunodeficiency virus protease inhibitors indinavir and saquinavir was evaluated in rhesus macaques for the first time. Indinavir effectively suppressed the growth of Plasmodium cynomolgi and Plasmodium knowlesi in vivo after a 7- or 3-day treatment, respectively, with clinically relevant doses, whereas saquinavir showed only weak activity against P. cynomolgi.
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Moneriz C, Marín-García P, García-Granados A, Bautista JM, Diez A, Puyet A. Parasitostatic effect of maslinic acid. I. Growth arrest of Plasmodium falciparum intraerythrocytic stages. Malar J 2011; 10:82. [PMID: 21477369 PMCID: PMC3087696 DOI: 10.1186/1475-2875-10-82] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2011] [Accepted: 04/10/2011] [Indexed: 12/30/2022] Open
Abstract
Background Natural products have played an important role as leads for the development of new drugs against malaria. Recent studies have shown that maslinic acid (MA), a natural triterpene obtained from olive pomace, which displays multiple biological and antimicrobial activities, also exerts inhibitory effects on the development of some Apicomplexan, including Eimeria, Toxoplasma and Neospora. To ascertain if MA displays anti-malarial activity, the main objective of this study was to asses the effect of MA on Plasmodium falciparum-infected erythrocytes in vitro. Methods Synchronized P. falciparum-infected erythrocyte cultures were incubated under different conditions with MA, and compared to chloroquine and atovaquone treated cultures. The effects on parasite growth were determined by monitoring the parasitaemia and the accumulation of the different infective stages visualized in thin blood smears. Results MA inhibits the growth of P. falciparum Dd2 and 3D7 strains in infected erythrocytes in, dose-dependent manner, leading to the accumulation of immature forms at IC50 concentrations, while higher doses produced non-viable parasite cells. MA-treated infected-erythrocyte cultures were compared to those treated with chloroquine or atovaquone, showing significant differences in the pattern of accumulation of parasitic stages. Transient MA treatment at different parasite stages showed that the compound targeted intra-erythrocytic processes from early-ring to schizont stage. These results indicate that MA has a parasitostatic effect, which does not inactivate permanently P. falciparum, as the removal of the compound allowed the infection to continue Conclusions MA displays anti-malarial activity at multiple intraerythrocytic stages of the parasite and, depending on the dose and incubation time, behaves as a plasmodial parasitostatic compound. This novel parasitostatic effect appears to be unrelated to previous mechanisms proposed for current anti-malarial drugs, and may be relevant to uncover new prospective plasmodial targets and opens novel possibilities of therapies associated to host immune response.
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Affiliation(s)
- Carlos Moneriz
- Departamento de Bioquímica y Biología Molecular IV, Universidad Complutense de Madrid, Facultad de Veterinaria, E28040 Madrid, Spain
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40
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Alfonso Y, Monzote L. HIV Protease Inhibitors: Effect on the Opportunistic Protozoan Parasites. THE OPEN MEDICINAL CHEMISTRY JOURNAL 2011; 5:40-50. [PMID: 21629510 PMCID: PMC3103880 DOI: 10.2174/1874104501105010040] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Revised: 05/22/2010] [Accepted: 06/28/2010] [Indexed: 11/22/2022]
Abstract
The impact of highly active antiretroviral therapy (HAART) in the natural history of AIDS disease has been allowed to prolong the survival of people with HIV infection, particularly whose with increased HIV viral load. Additionally, the antiretroviral therapy could exert a certain degree of protection against parasitic diseases. A number of studies have been evidenced a decrease in the incidence of opportunistic parasitic infections in the era of HAART. Although these changes have been attributed to the restoration of cell-mediated immunity, induced by either non-nucleoside reverse transcriptase inhibitors or HIV protease inhibitors, in combination with at least two nucleoside reverse transcriptase inhibitors included in HAART, there are evidence that the control of these parasitic infections in HIV-positive persons under HAART, is also induced by the inhibition of the proteases of the parasites. This review focuses on the principal available data related with therapeutic HIV-protease inhibitors and their in vitro and in vivo effects on the opportunistic protozoan parasites.
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Affiliation(s)
- Yenisey Alfonso
- Parasitology Department, Institute of Tropical Medicine “Pedro Kourí”, Cuba
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White RE, Powell DJ, Berry C. HIV proteinase inhibitors target the Ddi1-like protein of Leishmania parasites. FASEB J 2011; 25:1729-36. [PMID: 21266539 PMCID: PMC3739880 DOI: 10.1096/fj.10-178947] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
HIV proteinase inhibitors reduce the levels of Leishmania parasites in vivo and in vitro, but their biochemical target is unknown. We have identified an ortholog of the yeast Ddi1 protein as the only member of the aspartic proteinase family in Leishmania parasites, and in this study we investigate this protein as a potential target for the drugs. To date, no enzyme assay has been developed for the Ddi1 proteins, but Saccharomyces cerevisiae lacking the DDI1 gene secrete high levels of protein into the medium. We developed an assay in which these knockout yeast were functionally complemented to low secretion by introduction of genes encoding Ddi1 orthologs from Leishmania major or humans. Plasmid alone controls gave no complementation. Treatment of the Ddi1 transformants with HIV proteinase inhibitors showed differential effects dependent on the origin of the Ddi1. Dose responses allowed calculation of IC50 values; e.g., for nelfinavir, of 3.4 μM (human Ddi1) and 0.44 μM (Leishmania Ddi1). IC50 values with Leishmania constructs mirror the potency of inhibitors against parasites. Our results show that Ddi1 proteins are targets of HIV proteinase inhibitors and indicates the Leishmania Ddi1 as the likely target for these drugs and a potential target for antiparasitic therapy.—White, R. E., Powell, D. J., Berry, C. HIV proteinase inhibitors target the Ddi1-Like protein of Leishmania parasites.
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Affiliation(s)
- Rhian E White
- Cardiff School of Biosciences, Cardiff University, Cardiff, UK
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Burrows JN, Waterson D. Discovering New Medicines to Control and Eradicate Malaria. TOPICS IN MEDICINAL CHEMISTRY 2011. [DOI: 10.1007/7355_2011_14] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Barratt JLN, Harkness J, Marriott D, Ellis JT, Stark D. Importance of nonenteric protozoan infections in immunocompromised people. Clin Microbiol Rev 2010; 23:795-836. [PMID: 20930074 PMCID: PMC2952979 DOI: 10.1128/cmr.00001-10] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
There are many neglected nonenteric protozoa able to cause serious morbidity and mortality in humans, particularly in the developing world. Diseases caused by certain protozoa are often more severe in the presence of HIV. While information regarding neglected tropical diseases caused by trypanosomatids and Plasmodium is abundant, these protozoa are often not a first consideration in Western countries where they are not endemic. As such, diagnostics may not be available in these regions. Due to global travel and immigration, this has become an increasing problem. Inversely, in certain parts of the world (particularly sub-Saharan Africa), the HIV problem is so severe that diseases like microsporidiosis and toxoplasmosis are common. In Western countries, due to the availability of highly active antiretroviral therapy (HAART), these diseases are infrequently encountered. While free-living amoebae are rarely encountered in a clinical setting, when infections do occur, they are often fatal. Rapid diagnosis and treatment are essential to the survival of patients infected with these organisms. This paper reviews information on the diagnosis and treatment of nonenteric protozoal diseases in immunocompromised people, with a focus on patients infected with HIV. The nonenteric microsporidia, some trypanosomatids, Toxoplasma spp., Neospora spp., some free-living amoebae, Plasmodium spp., and Babesia spp. are discussed.
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Affiliation(s)
- J L N Barratt
- Department of Microbiology, St. Vincent's Hospital, Darlinghurst 2010, NSW, Australia.
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Gardiner DL, Skinner-Adams TS, Brown CL, Andrews KT, Stack CM, McCarthy JS, Dalton JP, Trenholme KR. Plasmodium falciparum: new molecular targets with potential for antimalarial drug development. Expert Rev Anti Infect Ther 2010; 7:1087-98. [PMID: 19883329 DOI: 10.1586/eri.09.93] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Malaria remains one of the world's most devastating infectious diseases. Drug resistance to all classes of antimalarial agents has now been observed, highlighting the need for new agents that act against novel parasite targets. The complete sequencing of the Plasmodium falciparum genome has allowed the identification of new molecular targets within the parasite that may be amenable to chemotherapeutic intervention. In this review, we investigate four possible targets for the future development of new classes of antimalarial agents. These targets include histone deacetylase, the aspartic proteases or plasmepsins, aminopeptidases and the purine salvage enzyme hypoxanthine-xanthine-guanine phosphoribosyltransferase.
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Affiliation(s)
- Donald L Gardiner
- Malaria Biology Laboratory, Queensland Institute of Medical Research, 300 Herston Road, Herston, QLD 4006, Australia.
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Ploemen IHJ, Prudêncio M, Douradinha BG, Ramesar J, Fonager J, van Gemert GJ, Luty AJF, Hermsen CC, Sauerwein RW, Baptista FG, Mota MM, Waters AP, Que I, Lowik CWGM, Khan SM, Janse CJ, Franke-Fayard BMD. Visualisation and quantitative analysis of the rodent malaria liver stage by real time imaging. PLoS One 2009; 4:e7881. [PMID: 19924309 PMCID: PMC2775639 DOI: 10.1371/journal.pone.0007881] [Citation(s) in RCA: 188] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 10/26/2009] [Indexed: 11/17/2022] Open
Abstract
The quantitative analysis of Plasmodium development in the liver in laboratory animals in cultured cells is hampered by low parasite infection rates and the complicated methods required to monitor intracellular development. As a consequence, this important phase of the parasite's life cycle has been poorly studied compared to blood stages, for example in screening anti-malarial drugs. Here we report the use of a transgenic P. berghei parasite, PbGFP-Luccon, expressing the bioluminescent reporter protein luciferase to visualize and quantify parasite development in liver cells both in culture and in live mice using real-time luminescence imaging. The reporter-parasite based quantification in cultured hepatocytes by real-time imaging or using a microplate reader correlates very well with established quantitative RT-PCR methods. For the first time the liver stage of Plasmodium is visualized in whole bodies of live mice and we were able to discriminate as few as 1–5 infected hepatocytes per liver in mice using 2D-imaging and to identify individual infected hepatocytes by 3D-imaging. The analysis of liver infections by whole body imaging shows a good correlation with quantitative RT-PCR analysis of extracted livers. The luminescence-based analysis of the effects of various drugs on in vitro hepatocyte infection shows that this method can effectively be used for in vitro screening of compounds targeting Plasmodium liver stages. Furthermore, by analysing the effect of primaquine and tafenoquine in vivo we demonstrate the applicability of real time imaging to assess parasite drug sensitivity in the liver. The simplicity and speed of quantitative analysis of liver-stage development by real-time imaging compared to the PCR methodologies, as well as the possibility to analyse liver development in live mice without surgery, opens up new possibilities for research on Plasmodium liver infections and for validating the effect of drugs and vaccines on the liver stage of Plasmodium.
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Affiliation(s)
- Ivo H J Ploemen
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre (RUNMC), Nijmegen, The Netherlands
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The Impact of HIV and Malaria Coinfection: What Is Known and Suggested Venues for Further Study. Interdiscip Perspect Infect Dis 2009; 2009:617954. [PMID: 19680452 PMCID: PMC2723755 DOI: 10.1155/2009/617954] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Accepted: 06/01/2009] [Indexed: 01/27/2023] Open
Abstract
HIV and malaria have similar global distributions. Annually, 500 million are infected and 1 million die because of malaria. 33 million have HIV and 2 million die from it each year. Minor effects of one infection on the disease course or outcome for the other would significantly impact public health because of the sheer number of people at risk for coinfection. While early population-based studies showed no difference in outcomes between HIV-positive and HIV-negative individuals with malaria, more recent work suggests that those with HIV have more frequent episodes of symptomatic malaria and that malaria increases HIV plasma viral load and decreases CD4+ T cells. HIV and malaria each interact with the host's immune system, resulting in a complex activation of immune cells, and subsequent dysregulated production of cytokines and antibodies. Further investigation of these interactions is needed to better define effects of coinfection.
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Parvanova I, Epiphanio S, Fauq A, Golde TE, Prudêncio M, Mota MM. A small molecule inhibitor of signal peptide peptidase inhibits Plasmodium development in the liver and decreases malaria severity. PLoS One 2009; 4:e5078. [PMID: 19337374 PMCID: PMC2659798 DOI: 10.1371/journal.pone.0005078] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 03/05/2009] [Indexed: 11/18/2022] Open
Abstract
The liver stage of Plasmodium's life cycle is the first, obligatory step in malaria infection. Decreasing the hepatic burden of Plasmodium infection decreases the severity of disease and constitutes a promising strategy for malaria prophylaxis. The efficacy of the gamma-secretase and signal peptide peptidase inhibitor LY411,575 in targeting Plasmodium liver stages was evaluated both in human hepatoma cell lines and in mouse primary hepatocytes. LY411,575 was found to prevent Plasmodium's normal development in the liver, with an IC50 of approximately 80 nM, without affecting hepatocyte invasion by the parasite. In vivo results with a rodent model of malaria showed that LY411,575 decreases the parasite load in the liver and increases by 55% the resistance of mice to cerebral malaria, one of the most severe malaria-associated syndromes. Our data show that LY411,575 does not exert its effect via the Notch signaling pathway suggesting that it may interfere with Plasmodium development through an inhibition of the parasite's signal peptide peptidase. We therefore propose that selective signal peptide peptidase inhibitors could be potentially used for preventive treatment of malaria in humans.
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Affiliation(s)
- Iana Parvanova
- Unidade de Malária, Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Sabrina Epiphanio
- Unidade de Malária, Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Abdul Fauq
- Department of Neuroscience, Mayo Clinic, College of Medicine, Jacksonville, Florida, United States of America
| | - Todd E. Golde
- Department of Neuroscience, Mayo Clinic, College of Medicine, Jacksonville, Florida, United States of America
| | - Miguel Prudêncio
- Unidade de Malária, Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Maria M. Mota
- Unidade de Malária, Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- * E-mail:
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