A replication competent Plasmodium falciparum parasite completely attenuated by dual gene deletion.
EMBO Mol Med
; 16(4): 723-754, 2024 Apr.
Article
in En
| MEDLINE
| ID: mdl-38514791
ABSTRACT
Vaccination with infectious Plasmodium falciparum (Pf) sporozoites (SPZ) administered with antimalarial drugs (PfSPZ-CVac), confers superior sterilizing protection against infection when compared to vaccination with replication-deficient, radiation-attenuated PfSPZ. However, the requirement for drug administration constitutes a major limitation for PfSPZ-CVac. To obviate this limitation, we generated late liver stage-arresting replication competent (LARC) parasites by deletion of the Mei2 and LINUP genes (mei2-/linup- or LARC2). We show that Plasmodium yoelii (Py) LARC2 sporozoites did not cause breakthrough blood stage infections and engendered durable sterilizing immunity against various infectious sporozoite challenges in diverse strains of mice. We next genetically engineered a PfLARC2 parasite strain that was devoid of extraneous DNA and produced cryopreserved PfSPZ-LARC2. PfSPZ-LARC2 liver stages replicated robustly in liver-humanized mice but displayed severe defects in late liver stage differentiation and did not form liver stage merozoites. This resulted in complete abrogation of parasite transition to viable blood stage infection. Therefore, PfSPZ-LARC2 is the next-generation vaccine strain expected to unite the safety profile of radiation-attenuated PfSPZ with the superior protective efficacy of PfSPZ-CVac.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Parasites
/
Malaria, Falciparum
/
Malaria Vaccines
Limits:
Animals
Language:
En
Journal:
EMBO Mol Med
Journal subject:
BIOLOGIA MOLECULAR
Year:
2024
Document type:
Article
Affiliation country:
Country of publication: