Identification of an 80-kilodalton membrane glycoprotein important for human T-cell leukemia virus type I and type II syncytium formation and infection.
Human T-cell leukemia virus type I and type II (HTLV-I and HTLV-II, respectively) infect certain sublines of the BJAB human B-cell line. We observed that the WH subline, but not the CC/84 subline, of BJAB cells were infectible by cell-free HTLV-I or HTLV-II and formed syncytia with cells infected by these retroviruses. This suggests that the BJAB-CC/84 cells possibly lack a membrane molecule(s) important for syncytium formation and infectibility. In order to identify this antigen, we generated polyclonal anti-BJAB-WH antisera which were adsorbed on BJAB-CC/84 cells. The adsorbed antisera bound only BJAB-WH and BJAB-CC/79 cells as demonstrated by complement-dependent cytotoxicity and flow cytometric assays. Furthermore, this adsorbed antisera bound several human T-cell clones, including SupT-1, as determined by flow cytometric assays. The adsorbed antiserum was monospecific as it immunoprecipitated only one 78- to 80-kDa protein from lysates of metabolically labeled BJAB-WH, BJAB-CC/79, and SupT-1, but not BJAB-CC/84, cells. The monospecific antisera detected a glycoprotein composed of a 64- to 66-kDa core protein containing tunicamycin-sensitive N-linked oligosaccharides. This membrane glycoprotein appears to be involved in HTLV-I- and HTLV-II-induced fusion and infection, as the monospecific antisera were capable of inhibiting both of these processes. The monospecific antisera diluted 1:50 and 1:90 inhibited 85 to 90% of syncytium formation induced in BJAB-WH, BJAB-CC/79, and SupT-1 cells cultured with HTLV-I- or HTLV-II-infected MT2, MoT, or FLW human T- or B-cell lines. At the same dilution, antisera inhibited 70 to 80% of infection of BJAB-WH cells by cell-free HTLV-I or HTLV-II. Thus, these studies indicate a role for a 78- to 80-kDa glycoprotein in HTLV-I or HTLV-II infection and syncytium formation.
Agadjanyan
M G
MG
Department of Medicine, University of Pennsylvania, Philadelphia 19104.
Ugen
K E
KE
Wang
B
B
Williams
W V
WV
Weiner
D B
DB
D000327:Adsorption; D000918:Antibody Specificity; D001402:B-Lymphocytes / Q000276:immunology / Q000382:microbiology*; D002459:Cell Fusion; D002460:Cell Line; D014644:Genetic Variation; D015726:Giant Cells / Q000502:physiology*; D015368:Human T-lymphotropic virus 1 / Q000254:growth & development*; D015367:Human T-lymphotropic virus 2 / Q000254:growth & development*; D006801:Humans; D008562:Membrane Glycoproteins / Q000302:isolation & purification* / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology
D008562:Membrane Glycoproteins