Identification of AXL as a co-receptor for human parvovirus B19 infection of human erythroid progenitors

Abstract

Parvovirus B19 (B19V) infects human erythroid progenitor cells (EPCs) and causes several hematological disorders and fetal hydrops. Amino acid (aa) 5–68 of minor capsid protein VP1 (VP1u 5–68aa ) is the minimal receptor binding domain for B19V to enter EPCs. Here, we carried out a genome-wide CRISPR-Cas9 guide RNA screen and identified tyrosine protein kinase receptor UFO (AXL) as a proteinaceous receptor for B19V infection of EPCs. AXL gene silencing in ex vivo expanded EPCs remarkably decreased B19V internalization and replication. Additions of the recombinant AXL extracellular domain or a polyclonal antibody against it upon infection efficiently inhibited B19V infection of ex vivo expanded EPCs. Moreover, B19V VP1u interacted with the recombinant AXL extracellular domain in vitro at a relatively high affinity ( K D = 103 nM). Collectively, we provide evidence that AXL is a co-receptor for B19V infection of EPCs.

Globoside and the mucosal pH mediate parvovirus B19 entry through the epithelial barrier

“…In line with this strategy, we found that the VP1u of B19V harbors an RBD, which interacts with an erythroid-specific surface molecule(s) required for virus internalization in the permissive EPCs [12,14,15]. Recently, the tyrosine protein kinase receptor UFO (AXL) was found to interact with the VP1u and to be required for virus uptake [45]. In the airway, AXL is expressed exclusively in the basal cells, which are progenitors of all cells in the respiratory epithelium.…”

Globoside and the mucosal pH mediate parvovirus B19 entry through the epithelial barrier

“…In line with this strategy, we found that the VP1u of B19V harbors an RBD, which interacts with an erythroid-specific surface molecule(s) required for virus internalization in the permissive EPCs [ 12 , 14 , 15 ]. Recently, the tyrosine protein kinase receptor UFO (AXL) was found to interact with the VP1u and to be required for virus uptake [ 16 ]. In the airway, AXL is expressed exclusively in the basal cells, which are progenitors of all cells in the respiratory epithelium.…”

“…The RBD structure adopts a spatial configuration of three alpha helices [ 13 ], and binds a receptor whose expression is restricted to erythroid cells [ 14 ], coinciding with the homing of BFU-E cells to the erythroblastic islands in the bone marrow and subsequent differentiation to CFU-E, proerythroblasts, and early basophilic erythroblasts [ 15 ]. The tyrosine protein kinase receptor UFO (AXL) was found to interact specifically with the RBD, and to contribute to virus uptake [ 16 ].…”

Identification of Host Restriction Factors Critical for Recombinant AAV Transduction of Polarized Human Airway Epithelium

“…The cultures/cells were then incubated in a humidified incubator with 5% CO 2 at 37°C for 2 hours before being washed with D-PBS three times. We carried out vector internalization assay using a previously published method (50). Cells were washed with Accutase (#AT104, Innovative Cell Technologies, Inc.) three times and then incubated with Accutase at 37°C for 1 hour.…”