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McLellan JL, Hanson KK. Differential effects of translation inhibitors on Plasmodium berghei liver stage parasites. Life Sci Alliance 2024; 7:e202302540. [PMID: 38575357 PMCID: PMC10994859 DOI: 10.26508/lsa.202302540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/19/2024] [Accepted: 03/19/2024] [Indexed: 04/06/2024] Open
Abstract
Increasing numbers of antimalarial compounds are being identified that converge mechanistically at inhibition of cytoplasmic translation, regardless of the molecular target or mechanism. A deeper understanding of how their effectiveness as liver stage translation inhibitors relates to their chemoprotective potential could prove useful. Here, we probed that relationship using the Plasmodium berghei-HepG2 liver stage infection model. After determining translation inhibition EC50s for five compounds, we tested them at equivalent effective concentrations to compare the parasite response to, and recovery from, a brief period of translation inhibition in early schizogony, followed by parasites to 120 h post-infection to assess antiplasmodial effects of the treatment. We show compound-specific heterogeneity in single parasite and population responses to translation inhibitor treatment, with no single metric strongly correlated to the release of hepatic merozoites for all compounds. We also demonstrate that DDD107498 is capable of exerting antiplasmodial effects on translationally arrested liver stage parasites and uncover unexpected growth dynamics during the liver stage. Our results demonstrate that translation inhibition efficacy does not determine antiplasmodial efficacy for these compounds.
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Affiliation(s)
- James L McLellan
- https://ror.org/01kd65564 Department of Molecular Microbiology and Immunology and STCEID, University of Texas at San Antonio, San Antonio, TX, USA
| | - Kirsten K Hanson
- https://ror.org/01kd65564 Department of Molecular Microbiology and Immunology and STCEID, University of Texas at San Antonio, San Antonio, TX, USA
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2
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McLellan JL, Garcia-Vilanova A, Hanson KK. An Optimized P. berghei Liver Stage-HepG2 Infection Model for Simultaneous Quantitative Bioimaging of Host and Parasite Nascent Proteomes. Bio Protoc 2024; 14:e4952. [PMID: 38464937 PMCID: PMC10917691 DOI: 10.21769/bioprotoc.4952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/10/2024] [Accepted: 02/05/2024] [Indexed: 03/12/2024] Open
Abstract
The Plasmodium parasites that cause malaria undergo an obligate, asymptomatic developmental stage in the host liver before initiating the symptomatic blood-stage infection. The parasite liver stage is a key intervention point for antimalarial chemoprophylaxis: successful targeting of liver-stage parasites prevents disease development in individuals and can help to reduce parasite transmission in populations, as the gametocyte forms that transmit infection to mosquitos are exclusively found in the blood stage. Antimalarial drugs that can target multiple parasite stages are thus highly desirable, and one emerging cellular target for such multistage active compounds is the process of protein synthesis or translation. Quantitative study of liver stage translation, and thus mechanistic evaluation of translation inhibitors against liver stage parasites, is not amenable to the methods allowing quantification of asexual blood stage translation, such as radiolabeled amino acid incorporation or lysate-based translation of reporter transcripts. Here, we present a method using o-propargyl puromycin (OPP) labeling of host and parasite nascent proteomes in the P. berghei-HepG2 infection model, followed by automated confocal image acquisition and computational separation of P. berghei vs. H. sapiens nascent proteome signals to allow simultaneous readout of the effects of translation inhibitors on both host and parasite. This protocol details our HepG2 cell culture and infected monolayer handling optimized for microscopy, our OPP labeling workflow, and our approach to automated confocal imaging, image processing, and data analysis. Key features • Uses the o-propargyl puromycin labeling technique developed by Liu et al. to quantitatively analyze protein synthesis in Plasmodium berghei liver-stage parasites in actively translating hepatoma cells. • This quantitative approach should be adaptable for other puromycin-sensitive intracellular pathogens residing in actively translating host cells. • The P. berghei-infected HepG2 recovery and reseeding protocol presented here is of use in applications beyond nascent proteome labeling and quantification.
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Affiliation(s)
- James L. McLellan
- Department of Molecular Microbiology and Immunology and STCEID,
University of Texas at San Antonio, San Antonio, TX, USA
| | - Andreu Garcia-Vilanova
- Department of Molecular Microbiology and Immunology and STCEID,
University of Texas at San Antonio, San Antonio, TX, USA
| | - Kirsten K. Hanson
- Department of Molecular Microbiology and Immunology and STCEID,
University of Texas at San Antonio, San Antonio, TX, USA
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Collins JE, Lee JW, Rocamora F, Saggu GS, Wendt KL, Pasaje CFA, Smick S, Santos NM, Paes R, Jiang T, Mittal N, Luth MR, Chin T, Chang H, McLellan JL, Morales-Hernandez B, Hanson KK, Niles JC, Desai SA, Winzeler EA, Cichewicz RH, Chakrabarti D. Antiplasmodial peptaibols act through membrane directed mechanisms. Cell Chem Biol 2024; 31:312-325.e9. [PMID: 37995692 PMCID: PMC10923054 DOI: 10.1016/j.chembiol.2023.10.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 08/29/2023] [Accepted: 10/27/2023] [Indexed: 11/25/2023]
Abstract
Our previous study identified 52 antiplasmodial peptaibols isolated from fungi. To understand their antiplasmodial mechanism of action, we conducted phenotypic assays, assessed the in vitro evolution of resistance, and performed a transcriptome analysis of the most potent peptaibol, HZ NPDG-I. HZ NPDG-I and 2 additional peptaibols were compared for their killing action and stage dependency, each showing a loss of digestive vacuole (DV) content via ultrastructural analysis. HZ NPDG-I demonstrated a stepwise increase in DV pH, impaired DV membrane permeability, and the ability to form ion channels upon reconstitution in planar membranes. This compound showed no signs of cross resistance to targets of current clinical candidates, and 3 independent lines evolved to resist HZ NPDG-I acquired nonsynonymous changes in the P. falciparum multidrug resistance transporter, pfmdr1. Conditional knockdown of PfMDR1 showed varying effects to other peptaibol analogs, suggesting differing sensitivity.
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Affiliation(s)
- Jennifer E Collins
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL 32826, USA
| | - Jin Woo Lee
- Department of Chemistry and Biochemistry, Institute for Natural Products Applications & Research Technologies, University of Oklahoma, Norman OK 73019, USA
| | - Frances Rocamora
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Gagandeep S Saggu
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| | - Karen L Wendt
- Department of Chemistry and Biochemistry, Institute for Natural Products Applications & Research Technologies, University of Oklahoma, Norman OK 73019, USA
| | - Charisse Flerida A Pasaje
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Sebastian Smick
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Natalia Mojica Santos
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL 32826, USA
| | - Raphaella Paes
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL 32826, USA
| | - Tiantian Jiang
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Nimisha Mittal
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Madeline R Luth
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Taylor Chin
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Howard Chang
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - James L McLellan
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas San Antonio, San Antonio, TX 78249, USA
| | - Beatriz Morales-Hernandez
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas San Antonio, San Antonio, TX 78249, USA
| | - Kirsten K Hanson
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas San Antonio, San Antonio, TX 78249, USA
| | - Jacquin C Niles
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Sanjay A Desai
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| | - Elizabeth A Winzeler
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA.
| | - Robert H Cichewicz
- Department of Chemistry and Biochemistry, Institute for Natural Products Applications & Research Technologies, University of Oklahoma, Norman OK 73019, USA.
| | - Debopam Chakrabarti
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL 32826, USA.
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McLellan JL, Sausman W, Reers AB, Bunnik EM, Hanson KK. Single-cell quantitative bioimaging of P. berghei liver stage translation. mSphere 2023; 8:e0054423. [PMID: 37909773 PMCID: PMC10732057 DOI: 10.1128/msphere.00544-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 09/25/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Plasmodium parasites cause malaria in humans. New multistage active antimalarial drugs are needed, and a promising class of drugs targets the core cellular process of translation, which has many potential molecular targets. During the obligate liver stage, Plasmodium parasites grow in metabolically active hepatocytes, making it challenging to study core cellular processes common to both host cells and parasites, as the signal from the host typically overwhelms that of the parasite. Here, we present and validate a flexible assay to quantify Plasmodium liver stage translation using a technique to fluorescently label the newly synthesized proteins of both host and parasite followed by computational separation of their respective nascent proteomes in confocal image sets. We use the assay to determine whether a test set of known compounds are direct or indirect liver stage translation inhibitors and show that the assay can also predict the mode of action for novel antimalarial compounds.
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Affiliation(s)
- James L. McLellan
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, Texas, USA
| | - William Sausman
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, Texas, USA
| | - Ashley B. Reers
- Department of Microbiology, Immunology, and Molecular Genetics, Long School of Medicine, University of Texas Health Science Center, San Antonio, Texas, USA
| | - Evelien M. Bunnik
- Department of Microbiology, Immunology, and Molecular Genetics, Long School of Medicine, University of Texas Health Science Center, San Antonio, Texas, USA
| | - Kirsten K. Hanson
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, Texas, USA
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McLellan JL, Hanson KK. Translation inhibition efficacy does not determine the Plasmodium berghei liver stage antiplasmodial efficacy of protein synthesis inhibitors. bioRxiv 2023:2023.12.07.570699. [PMID: 38106175 PMCID: PMC10723475 DOI: 10.1101/2023.12.07.570699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Protein synthesis is a core cellular process, necessary throughout the complex lifecycle of Plasmodium parasites, thus specific translation inhibitors would be a valuable class of antimalarial drugs, capable of both treating symptomatic infections in the blood and providing chemoprotection by targeting the initial parasite population in the liver, preventing both human disease and parasite transmission back to the mosquito host. As increasing numbers of antiplasmodial compounds are identified that converge mechanistically at inhibition of cytoplasmic translation, regardless of molecular target or mechanism, it would be useful to gain deeper understanding of how their effectiveness as liver stage translation inhibitors relates to their chemoprotective potential. Here, we probed that relationship using the P. berghei-HepG2 liver stage infection model. Using o-propargyl puromycin-based labeling of the nascent proteome in P. berghei-infected HepG2 monolayers coupled with automated confocal feedback microscopy to generate unbiased, single parasite image sets of P. berghei liver stage translation, we determined translation inhibition EC50s for five compounds, encompassing parasite-specific aminoacyl tRNA synthetase inhibitors, compounds targeting the ribosome in both host and parasite, as well as DDD107498, which targets Plasmodium eEF2, and is a leading antimalarial candidate compound being clinically developed as cabamiquine. Compounds were then tested at equivalent effective concentrations to compare the parasite response to, and recovery from, a brief period of translation inhibition in early schizogony, with parasites followed up to 120 hours post-infection to assess liver stage antiplasmodial effects of the treatment. Our data conclusively show that translation inhibition efficacy per se does not determine a translation inhibitor's antiplasmodial efficacy. DDD107498 was the least effective translation inhibitor, yet exerted the strongest antimalarial effects at both 5x- and 10x EC50 concentrations. We show compound-specific heterogeneity in single parasite and population responses to translation inhibitor treatment, with no single metric strongly correlated to release of hepatic merozoites for all compound, demonstrate that DDD107498 is capable of exerting antiplasmodial effects on translationally arrested liver stage parasites, and uncover unexpected growth dynamics during the liver stage. Our results demonstrate that translation inhibition efficacy cannot function as a proxy for antiplasmodial effectiveness, and highlight the importance of exploring the ultimate, as well as proximate, mechanisms of action of these compounds on liver stage parasites.
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Affiliation(s)
- James L. McLellan
- University of Texas at San Antonio, Department of Molecular Microbiology and Immunology and STCEID, San Antonio TX, USA
| | - Kirsten K. Hanson
- University of Texas at San Antonio, Department of Molecular Microbiology and Immunology and STCEID, San Antonio TX, USA
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Abstract
Plasmodium parasite resistance to existing antimalarial drugs poses a devastating threat to the lives of many who depend on their efficacy. New antimalarial drugs and novel drug targets are in critical need, along with novel assays to accelerate their identification. Given the essentiality of protein synthesis throughout the complex parasite lifecycle, translation inhibitors are a promising drug class, capable of targeting the disease-causing blood stage of infection, as well as the asymptomatic liver stage, a crucial target for prophylaxis. To identify compounds capable of inhibiting liver stage parasite translation, we developed an assay to visualize and quantify translation in the P. berghei-HepG2 infection model. After labeling infected monolayers with o-propargyl puromycin (OPP), a functionalized analog of puromycin permitting subsequent bioorthogonal addition of a fluorophore to each OPP-terminated nascent polypetide, we use automated confocal feedback microscopy followed by batch image segmentation and feature extraction to visualize and quantify the nascent proteome in individual P. berghei liver stage parasites and host cells simultaneously. After validation, we demonstrate specific, concentration-dependent liver stage translation inhibition by both parasite-selective and pan-eukaryotic active compounds, and further show that acute pre-treatment and competition modes of the OPP assay can distinguish between direct and indirect translation inhibitors. We identify a Malaria Box compound, MMV019266, as a direct translation inhibitor in P. berghei liver stages and confirm this potential mode of action in P. falciparum asexual blood stages.
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Affiliation(s)
- James L McLellan
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA
| | - William Sausman
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA
| | - Ashley B Reers
- Department of Microbiology, Immunology, and Molecular Genetics, Long School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA
| | - Evelien M Bunnik
- Department of Microbiology, Immunology, and Molecular Genetics, Long School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA
| | - Kirsten K Hanson
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA
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