SCREENING FOR IMMUNOSTIMULATORY DNA FUNCTIONAL MODIFYERS

摘要

Synthetic single-stranded oligodeoxynucleotides (ODN) containing unmethylated CpG dinucleotides in specific base contexts or T-rich motifs, including poly T, (immunostimulatory ODNs) are immunostimulatory for B lymphocytes and other lymphoid and nonlymphoid cells, while ODN without these CpG sequences or T-rich motifs (non-immunostimulatory ODNs) are not. Mechanisms by which cells discriminate between immunostimulatory and non-immunostimulatory ODNs are hitherto unknown. The invention is based upon the purification and identification of immunostimulatory DNA binding proteins, naturally occurring cellular proteins which bind specifically to immunostimulatory ODNs and mediate the observed immunostimulatory effects. These proteins are RNA binding proteins and include nucleolin, hnRNP A1, hnRNP D, AUF1, and lupus La protein. The invention provides methods for the use of RNA binding proteins as immunostimulatory DNA binding proteins. Provided are methods useful for screening and identifying immunostimulatory DNA inhibitors, competitors, agonists, mimics, and cellular targets. Methods are also provided for using immunostimulatory DNA binding proteins to optimize immunostimulatory ODN for immune stimulation. Also provided are an isolated immunostimulatory ODN-immunostimulatory DNA binding protein complex and a kit for identifying cellular targets of immunostimulatory DNA.