RT Journal Article SR Electronic T1 Plasmodium falciparum exploits CD44 as a co-receptor for erythrocyte invasion JF bioRxiv FD Cold Spring Harbor Laboratory SP 2023.04.12.536503 DO 10.1101/2023.04.12.536503 A1 Barbara Baro-Sastre A1 Chi Yong Kim A1 Carrie Lin A1 Angel K. Kongsomboonvech A1 Marilou Tetard A1 Nichole D. Salinas A1 Niraj H. Tolia A1 Elizabeth S. Egan YR 2023 UL http://biorxiv.org/content/early/2023/04/12/2023.04.12.536503.abstract AB The malaria parasite Plasmodium falciparum invades and replicates asexually within human erythrocytes. CD44 expressed on erythrocytes was previously identified as an important host factor for P. falciparum infection through a forward genetic screen, but little is known about its regulation or function in these cells, nor how it may be utilized by the parasite. We found that CD44 can be efficiently deleted from primary human hematopoietic stem cells using CRISPR/Cas9 genome editing, and that the efficiency of ex-vivo erythropoiesis to enucleated cultured red blood cells (cRBCs) is not impacted by lack of CD44. However, the rate of P. falciparum invasion was substantially reduced in CD44-null cRBCs relative to isogenic wild-type (WT) control cells, validating CD44 as an important host factor for this parasite. We identified two P. falciparum invasion ligands as binding partners for CD44, Erythrocyte Binding Antigen-175 (EBA-175) and EBA-140, and demonstrated that their ability to bind to human erythrocytes relies primarily on their canonical receptors-glycophorin A and glycophorin C, respectively. We further show that EBA-175 induces phosphorylation of erythrocyte cytoskeletal proteins in a CD44-dependent manner. Our findings support a model where P. falciparum exploits CD44 as a co-receptor during invasion of human erythrocytes, stimulating CD44-dependent phosphorylation of host cytoskeletal proteins that alter host cell deformability and facilitate parasite entry.Competing Interest StatementThe authors have declared no competing interest.