The present invention provides compounds and compositions that can modulate formation of Toll-like receptor 3 (TLR3) and double-stranded RNA (dsRNA) complex, and methods for using the same. In particular, some aspects of the invention provide compounds of the formula: compositions comprising and methods for using the same, where n, Ar1, Ar2, X1, X2, X3, Z1, and Z2 are those defined herein.