Fig. 1.

TLR3 binding to dsRNA is saturable, specific, and a function of dsRNA size. Capture (A) and competition (B–D) ELISAs were performed by using immobilized 540-bp dsRNA at pH 6.0. (A) TLR3ecd binds saturably to dsRNA. (B) Soluble polyI:C and dsRNA (139 bp) inhibit the binding of TLR3ecd (1 μg/ml) to immobilized dsRNA at comparable concentrations. (C) dsDNA (532 bp), ssDNA (90 bp), and ssRNA (633 bp) inhibit binding much less effectively than dsRNA (540 bp). (D) Inhibition of TLR3ecd binding to immobilized dsRNA depends upon dsRNA length. Experiments were performed in triplicate, and error bars indicate one standard deviation.