FIG. 1.

Specificity of the E2-CD81 interaction. CD81 expression was monitored on parental (shaded graphs) and CD81-expressing (open graphs) KM3 (A) and RBL (B) cell lines with a pool of anti-CD81 MAbs (ID6, 4TM-1, and 1.3.3.22) and anti-mouse IgG-PE. Soluble E2₆₆₁ was allowed to bind to KM3 (C) and RBL (D) parental cell lines (shaded graphs) and those stably expressing human CD81 (open graphs), cell-bound antigen was visualized with MAb 11/4b specific for the C-terminal tag, anti-rat IgG-PE, and FACS analysis.