Sialyl-T Antigen: A Novel Red Blood Cell Determinant for Plasmodium falciparum Invasion.

Malaria continues to pose significant health challenges globally despite advances in control measures. Plasmodium falciparum, the parasite responsible for most severe malaria cases, uses multiple redundant invasion pathways to enter the red blood cell (RBC) during the blood stage of infection. Through a combination of RNA interference screening in erythroid cells and validation by CRISPR/Cas9-mediated knockout in primary human hematopoietic stem cells, we identified the glycosyltransferase Core 1 Synthase Glycoprotein-N-Acetylgalactosamine 3-Beta-Galactosyltransferase 1 (C1GALT1) as a novel host determinant for P. falciparum invasion. Analyses of C1GALT1-deficient cultured reticulocytes and RBCs with the glycophorin A/B-null MkMk blood group phenotype demonstrated that the C1GALT1-dependent α(2-3) sialic acid structures within mucin-type O-glycans are crucial for efficient invasion of both sialic acid-dependent and sialic acid-independent P. falciparum strains, but not the primate malaria parasite Plasmodium knowlesi. However, different P. falciparum parasite strains exhibit variable dependencies on distinct sialic acid configurations on the RBC surface. Overall, our findings highlight a key role for RBC glycans in malaria infection.