Plasmodium falciparum gene expression signatures and antibody profiling implicate the fikk, phist, and surf multigene families in severe malaria syndromes

Abstract

Plasmodium falciparum is the most virulent Plasmodium species, responsible for the life-threatening severe malaria syndromes of cerebral malaria and severe malarial anemia. In a Mali case-control study, we determined parasite gene expression in cerebral malaria, severe malarial anemia, and concurrent disease featuring both syndromes by comparing RNA-seq data from severe malaria cases to matched uncomplicated malaria controls with or without a history of cerebral malaria. While severe malarial anemia comparisons produced comparatively low levels of differential expression, the comparisons of cerebral malaria and concurrent disease yielded significant differential expression of multigene families (fikk, phist, and surf) implicated in processes that escalate disease severity, such as cytoadherence and erythrocytic remodeling. We probed custom microarrays featuring these antigens with acute and convalescent sera. Children with severe malaria developed antibody responses to subsets of these proteins following severe malaria infection, suggesting exposure to these antigens during illness and their potential as targets in the development of natural protective immunity against severe malaria. Our findings address knowledge gaps surrounding parasite gene expression in severe malarial anemia. Further, these results broaden the scope of multigene families implicated in severe malaria pathogenesis and underscore the utility of transcriptome-wide approaches for a comprehensive understanding of severe disease, particularly when developing therapeutics or vaccines.

Keywords: Cerebral malaria; Children; Differential expression; Gene ontology; Mali; Plasmodium falciparum; Protein microarray; RNA sequencing; Severe malarial anemia; Vaccine candidates.