Generation of a Genetically Modified Chimeric Plasmodium falciparum Parasite Expressing Plasmodium vivax Circumsporozoite Protein for Malaria Vaccine Development

Miyazaki et al., Front Cell Infect Micorbiol. 2020 Dec 17

ABSTRACT

Chimeric rodent malaria parasites with the endogenous circumsporozoite protein (csp) gene replaced with csp from the human parasites Plasmodium falciparum (Pf) and P. vivax (Pv) are used in preclinical evaluation of CSP vaccines. Chimeric rodent parasites expressing PfCSP have also been assessed as whole sporozoite (WSP) vaccines. Comparable chimeric P. falciparum parasites expressing CSP of P. vivax could be used both for clinical evaluation of vaccines targeting PvCSP in controlled human P. falciparum infections and in WSP vaccines targeting P. vivax and P. falciparum. We generated chimeric P. falciparum parasites expressing both PfCSP and PvCSP. These PfPvCSP parasites produced sporozoite comparable to wild type P. falciparum parasites and expressed PfCSP and PvCSP on the sporozoite surface. PfPvCSP sporozoites infected human hepatocytes and induced antibodies to the repeats of both PfCSP and PvCSP after immunization of mice. These results support the use of PfPvCSP sporozoites in studies optimizing vaccines targeting PvCSP.

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