The interaction of heparin sulfate and adeno-associated virus 2.
Recently heparan sulfate was proposed as the host cell receptor for the dependovirus, adeno-associated virus type 2 (AAV2). We show that although heparan sulfate on the cell surface may contribute to the binding of AAV2 to permissive cells, the amount of heparan sulfate on the cell surface as determined by flow cytometry using four different monoclonal antibodies does not correlate with AAV2 binding to cells or recombinant AAV2 transduction efficiency. Experiments with either mutant CHO cells or cells treated with chlorate to remove sulfate groups showed that sulfation was not absolutely required for infection or binding: in the absence of cell surface sulfation, recombinant AAV2 was still able to be transduced in previously permissive cells. Heparin is commonly used as a substitute in studies of the interaction between heparan sulfate and ligand, and we demonstrate that the binding affinity of AAV2/heparin is low, with a K(d) value of approximately 2.0 nM. A study of the direct interaction between AAV2 and artificial glycosaminoglycans showed that a high degree of sulfation on heparin was critical for the ability to bind AAV2 and compete rAAV2 transduction and that both O- and N-sulfate groups are required. Overall, our data suggest that, as has been shown for other viruses, the presence of a high-affinity AAV2 receptor mediates AAV2 infection in addition to the low-affinity heparan sulfate binding.
Qiu
J
J
Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA. QuiJ@nih.gov
Handa
A
A
Kirby
M
M
Brown
K E
KE
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D001665:Binding Sites / Q000187:drug effects; D016466:CHO Cells; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000821:virology; D002704:Chlorates / Q000378:metabolism; D006224:Cricetinae; D000229:Dependovirus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D005434:Flow Cytometry; D017930:Genes, Reporter / Q000235:genetics; D006025:Glycosaminoglycans / Q000378:metabolism; D006493:Heparin / Q000378:metabolism; D006497:Heparan Sulfate / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D009154:Mutation / Q000235:genetics; D011991:Receptors, Virus / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D013816:Thermodynamics; D014161:Transduction, Genetic / Q000187:drug effects
D000911:Antibodies, Monoclonal; D002704:Chlorates; D006025:Glycosaminoglycans; D006493:Heparin; D006497:Heparan Sulfate; D011991:Receptors, Virus; D013431:Sulfates; C022842:chloric acid