摘要: Immunostimulatory sequence-specific RNA oligonucleotides corresponding to 3' terminal sequences of single-stranded minus-sense genomic RNAs are provided. Also provided compositions and methods relating an immunostimulatory 4-mer motif as 5'-C/U-U-G/U-U-3'. Incorporation this short is sufficient confer new altered properties in existing oligonucleotides, including CpG oligodeoxynucleotides. for use the DNA:RNA chimeric invention induce immune response vitro vivo, well treat allergy, asthma, infection, cancer a subject. Single-stranded oligoribonucleotides believed signal through Toll-like receptor (TLR) chosen from TLR9, TLR8, TLR7, TLR3. The can also be used method screen TLR antagonists.