Experimentally engineered mutations in a ubiquitin hydrolase, UBP-1, modulate<i>in vivo</i>resistance to artemisinin and chloroquine in<i>Plasmodium berghei</i>

Simwela, Nelson V.; Hughes, Katie R.; Roberts, A.; Rennie, Michael T; Barrett, Michael P.; Waters, Andrew P.

doi:10.1101/2019.12.12.874990

Cited by 3 publications

(8 citation statements)

References 33 publications

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“…A deletion in PfUBP1, which encodes a putative deubiquitinating enzyme, was associated with increased ring survival. Two mutations in the P. chabaudi homolog of this protein were associated with artemisinin resistance in a murine genetic cross 49 , mutations were linked to artemisinin resistance in P. falciparum in vitro 50 and P. berghei in mice 51 , but not to clinical resistance 52 , and the protein was shown by a nity labelling to associate with PfK13 53 . Our results support these limited data identifying PfUBP1 mutations as potential secondary mediators of artemisinin resistance.…”

Section: Discussionmentioning

confidence: 97%

Decreased susceptibility of Plasmodium falciparum to both dihydroartemisinin and lumefantrine in northern Uganda

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Okitwi

et al. 2022

Preprint

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Artemisinin resistance may facilitate selection of Plasmodium falciparum resistant to combination therapy partner drugs. We evaluated 99 P. falciparum isolates collected in 2021 from northern Uganda, where resistance-associated PfK13 C469Y and A675V mutations have emerged, and eastern Uganda, where these mutations are uncommon. With the ex vivo ring survival assay, isolates with the 469Y mutation (median survival 7.3% for mutant, 2.5% mixed, and 1.4% wild type) and/or mutations in Pfcoronin or falcipain-2a, had significantly greater survival; all isolates with survival > 5% had mutations in at least one of these proteins. With ex vivo growth inhibition assays, susceptibility to lumefantrine (IC50 14.6 vs. 6.9 nM, p < 0.0001) and dihydroartemisinin (2.3 vs. 1.5 nM, p = 0.003) was decreased in northern vs. eastern Uganda; 14/49 northern vs. 0/38 eastern isolates had lumefantrine IC50 > 20 nM (p = 0.0002). Targeted sequencing of 819 isolates from 2015-21 identified multiple polymorphisms associated with altered drug susceptibility, notably decreased susceptibility to lumefantrine with PfK13 469Y (p = 6x10− 8) and chloroquine with PfCRT mutations (p = 1x10− 20). Our results raise concern regarding activity of artemether-lumefantrine, the first-line antimalarial in Uganda.

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Section: Discussionmentioning

confidence: 97%

Decreased susceptibility of Plasmodium falciparum to both dihydroartemisinin and lumefantrine in northern Uganda

Tumwebaze

Conrad

Okitwi

et al. 2022

Preprint

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“…For instance, pyridones, compounds targeting the cytochrome bc1 complex, have been evaluated in P. yoelii because of the close genetic similarity of this target protein between P. yoelii and P. falciparum as opposed to the slightly divergent P. berghei (Yeates et al ., 2008 ). Moreover, P. berghei is inherently less susceptible to some classes of endoperoxides (Lee et al ., 2018 ; Simwela et al ., 2020 a , 2020 b ) while P. yoelii is naturally resistant to quinolines (Warhurst and Killick-Kendrick, 1967 ). Some of the differences in drug susceptibility between RMPs ( P. berghei , P. yoelii ) and P. falciparum could be due to reticulocyte preferences for the former which provide rich metabolic energy sources with the potential to cushion the killing effect of antimalarial agents (Srivastava et al ., 2015 ).…”

Section: Applications Of Animal Models In Malariamentioning

confidence: 99%

“…However, with the development of recent highly precise genome editing technologies such as CRISPR-Cas9, instead of introducing P. falciparum antimalarial drug-resistant candidate alleles in RMPs as transgenes, orthologous polymorphisms can be introduced with precision in attempts to characterize phenotypes based on assumed gene function conservation. Such CRISPR approaches have recently been used in P. berghei in vivo to validate UBP-1 and Kelch13 ART resistance mutations which were first identified in P. chabaudi and P. falciparum , respectively (Simwela et al ., 2020 a , 2020 b ). Even though evolutionary divergence between RMPs and P. falciparum means overall protein sequence identities cannot be always highly conserved (e.g.…”

Section: Applications Of Animal Models In Malariamentioning

confidence: 99%

“…Even though evolutionary divergence between RMPs and P. falciparum means overall protein sequence identities cannot be always highly conserved (e.g. P. berghei and P. falciparum UBP-1 share 41% sequence identity), there appears to be a reasonable degree of similarity in the functional domains (Simwela et al ., 2020 a ). Meanwhile, certain drug resistance genes are highly conserved, for instance P. berghei and P. falciparum Kelch13 share over 80% sequence identity (Simwela et al ., 2020 b ).…”

Section: Applications Of Animal Models In Malariamentioning

confidence: 99%

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Current status of experimental models for the study of malaria

Simwela

Waters

2022

Parasitology

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Infection by malaria parasites (Plasmodium spp.) remains one of the leading causes of morbidity and mortality, especially in tropical regions of the world. Despite the availability of malaria control tools such as integrated vector management and effective therapeutics, these measures have been continuously undermined by the emergence of vector resistance to insecticides or parasite resistance to frontline antimalarial drugs. Whilst the recent pilot implementation of the RTS,S malaria vaccine is indeed a remarkable feat, highly effective vaccines against malaria remain elusive. The barriers to effective vaccines result from the complexity of both the malaria parasite lifecycle and the parasite as an organism itself with consequent major gaps in our understanding of their biology. Historically and due to the practical and ethical difficulties of working with human malaria infections, research into malaria parasite biology has been extensively facilitated by animal models. Animals have been used to study disease pathogenesis, host immune responses and their (dys)regulation and further disease processes such as transmission. Moreover, animal models remain at the forefront of pre-clinical evaluations of antimalarial drugs (drug efficacy, mode of action, mode of resistance) and vaccines. In this review, we discuss commonly used animal models of malaria, the parasite species used and their advantages and limitations which hinder their extrapolation to actual human disease. We also place into this context the most recent developments such as organoid technologies and humanized mice.

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“…Several other proteins, mostly from the K13-compartment, confer ART resistance in RSA either when downregulated or when mutated [7][8][9][10][11] . Their contribution to resistance in the field is largely unknown.…”

Section: Introductionmentioning

confidence: 99%

Impact of different mutations on Kelch13 protein levels, ART resistance and fitness cost inPlasmodium falciparumparasites

Behrens

Schmidt

Peigney

et al. 2022

Preprint

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Combination therapies containing Artemisinin derivatives (ART) are the first line treatment of malaria but their effectiveness is reduced by resistance due to a fraction of ring stage Plasmodium parasites surviving high ART levels. Resistance-causing kelch13 (k13) mutations are common in South East Asia but were only recently and sparsely detected in Africa, which experiences the highest malaria burden. Kelch13 shares a cellular compartment with other proteins (KICs) several of which cause resistance when inactivated or, in a few cases, when mutated. To see if the sparse detection of resistance mutations in Africa is due to unknown mutations, we tested 135 k13 and kic mutations detected mostly in African field isolates. No kic mutation caused resistance but two in k13, V520A and V589I, did. These mutations were geographically much more widespread in Africa but conferred lower levels of resistance than known ART resistance mutations. A dissection of the mechanism using isogenic parasites with different k13 mutations and parasites that we selected for even higher ART resistance, showed that resistance is a function of K13 protein levels in ring-stage parasites and correlates with the fitness cost. This indicated that hyper-resistance is unlikely to arise in the field. Double mutations in k13 had not even additive effects and combinations including a non-k13 mutation led to high fitness costs, suggesting that such combinations also pose no risk for higher resistance in the field. Overall, our results indicate that resistance is restricted by a proportional fitness cost but that incidence-lowering measures may favor high-resistance mutations.SignificanceOur findings indicate that hyper-resistant parasites are unlikely to occur in endemic settings due to the proportional fitness cost. Mutations within k13 were not additive and mutations outside k13 had a disproportionally high fitness cost. The strong influence of the fitness cost may have favored moderate frequencies of the resistance mutations with low fitness cost detected in many African settings that we characterized in this study. These mutations, so far gone unnoticed, may be optimal in high endemicity regions, where relative drug use is presumably low but frequent multiple infections increase competition. A given endemic setting may thus favor variants with K13 levels for an optimal resistance-fitness balance which is relevant for incidence-lowering interventions.

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Experimentally engineered mutations in a ubiquitin hydrolase, UBP-1, modulatein vivoresistance to artemisinin and chloroquine inPlasmodium berghei

Abstract: 1 resistance to artemisinin and chloroquine in Plasmodium berghei.

Cited by 3 publications

References 33 publications

Decreased susceptibility of Plasmodium falciparum to both dihydroartemisinin and lumefantrine in northern Uganda

Decreased susceptibility of Plasmodium falciparum to both dihydroartemisinin and lumefantrine in northern Uganda

Current status of experimental models for the study of malaria

Impact of different mutations on Kelch13 protein levels, ART resistance and fitness cost inPlasmodium falciparumparasites

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