The ESCRT-III machinery participates in the production of extracellular vesicles and protein export during Plasmodium falciparum infection.
PLoS Pathog 2021;
17:e1009455. [PMID:
33798247 PMCID:
PMC9159051 DOI:
10.1371/journal.ppat.1009455]
[Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 04/14/2021] [Accepted: 03/08/2021] [Indexed: 01/08/2023] Open
Abstract
Infection with Plasmodium falciparum enhances extracellular
vesicle (EV) production in parasitized red blood cells (pRBCs), an important
mechanism for parasite-to-parasite communication during the asexual
intraerythrocytic life cycle. The endosomal
sorting complex
required for transport
(ESCRT), and in particular the ESCRT-III sub-complex, participates in the
formation of EVs in higher eukaryotes. However, RBCs have lost the majority of
their organelles through the maturation process, including an important
reduction in their vesicular network. Therefore, the mechanism of EV production
in P. falciparum-infected RBCs remains to be
elucidated. Here we demonstrate that P.
falciparum possesses a functional ESCRT-III machinery
activated by an alternative recruitment pathway involving the action of PfBro1
and PfVps32/PfVps60 proteins. Additionally, multivesicular body formation and
membrane shedding, both reported mechanisms of EV production, were reconstituted
in the membrane model of giant unilamellar vesicles using the purified
recombinant proteins. Moreover, the presence of PfVps32, PfVps60 and PfBro1 in
EVs purified from a pRBC culture was confirmed by super-resolution microscopy
and dot blot assays. Finally, disruption of the PfVps60 gene
led to a reduction in the number of the produced EVs in the KO strain and
affected the distribution of other ESCRT-III components. Overall, our results
increase the knowledge on the underlying molecular mechanisms during malaria
pathogenesis and demonstrate that ESCRT-III P.
falciparum proteins participate in EV production.
Malaria is a disease caused by Plasmodium parasites that is
still a leading cause of death in many low-income countries, and for which
currently available therapeutic strategies are not succeeding in its control,
let alone eradication. An interesting feature observed after
Plasmodium invasion is the increase of extracellular
vesicles (EVs) generated by parasitized red blood cells (pRBCs), which lack a
vesicular trafficking that would explain EV production. Here, by combining
different approaches, we demonstrated the participation of the
endosomal sorting
complex required for
transport (ESCRT) machinery from Plasmodium
falciparum in the production of EVs in pRBCs. Moreover, we were
able to detect ESCRT-III proteins adjacent to the membrane of the host and in
EVs purified from a pRBC culture, which shows the export of these proteins and
their participation in EV production. Finally, the disruption of an ESCRT-III
associated gene, Pfvps60, led to a significant reduction in the
amount of EVs. Altogether, these results confirm ESCRT-III participation in EV
production and provide novel information on the P.
falciparum protein export mechanisms, which can be used for
the development of new therapeutic strategies against malaria, based on the
disruption of EV formation and trafficking.
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