title: Human T-cell lymphotropic virus type 1 (HTLV-1)-induced syncytium formation mediated by vascular cell adhesion molecule-1: evidence for involvement of cell adhesion molecules in HTLV-1 biology.
abstract: While studying the potential role of vascular cell adhesion molecule-1 (VCAM-1) in infection of endothelial cells by human immunodeficiency virus (HIV), we found that VCAM-1 can mediate human T-cell lymphotropic virus type 1 (HTLV-1)-induced syncytium formation. Both expression-vector-encoded and endogenously expressed VCAM-1 supported fusion of uninfected cells with HTLV-1-infected cells. Fusion was obtained with cell lines carrying the HTLV-1 genome and expressing viral proteins but not with an HTLV-1-transformed cell line that does not express viral proteins. In clones of VCAM-1-transfected cells, the degree of syncytium formation observed directly reflected the level of VCAM-1 expression. Syncytium formation between HTLV-1-expressing cells and VCAM-1+ cells could be blocked with antiserum against HTLV-1 gp46 and with a monoclonal antibody (MAb) against VCAM-1. Fusion was not blocked by antiserum against HIV or a MAb against VLA-4, the physiological counter-receptor for VCAM-1. The results indicate that VCAM-1 can serve as an accessory molecule or potential coreceptor for HTLV-1-induced cell fusion and provide direct evidence of a role for cell adhesion molecules in the biology of HTLV-1.
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. jhildret@welchlink.welch.jhu.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Hildreth
authors.forename: A
authors.initials: A
authors.lastname: Subramanium
authors.forename: R A
authors.initials: RA
authors.lastname: Hampton
mesh_terms: D002460:Cell Line; D004727:Endothelium / Q000821:virology*; D015490:HTLV-I Infections / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000502:physiology*; D006801:Humans; D019010:Vascular Cell Adhesion Molecule-1 / Q000502:physiology*; D014779:Virus Replication
chemical_list: D019010:Vascular Cell Adhesion Molecule-1