Cellular entry of pathogenic hantaviruses had been shown to be mediated by beta 3 integrins. However, no direct evidence exists that hantavirus binds to beta 3 integrins, and integrin beta 3 subunit is not expressed on some cells permissive to hantavirus infection. In this report, utilizing beta 3-integrin-transfected CHO cells, we demonstrated that integrin beta 3 subunit renders CHO cells susceptible to Chinese Hantaan virus (HTN) strain A9 (isolated in China), and the viral infection was correspondingly inhibited by antibodies to alpha v beta 3, alpha IIb beta 3, beta 3, and ow integrins. Furthermore, virus overlay protein-binding assay and 'quarternary Western' analysis indicate that HTN A9 directly interacts with beta 3 integrins and an unidentified 70 kDa protein. These findings indicate that beta 3 integrins play a crucial role in cellular entry of HTN A9 via specific interactions with the virus. In addition, a novel 70 kDa protein may serves as a candidate receptor or alternative cellular component for interaction with HTN. (c) 2005 Elsevier Inc. All rights reserved.