| Objective Systemic inflammatory response syndrome (SIRS) is a common complication in patients with extensive deep burns and severe traumas. If uncorrected, SIRS will lead to multiple organs dysfunction syndrome (MODS), which has a high mortality of 30% to 50%. Unfortunately, there are no effective anti-SIRS drugs have been developed in clinic. Because bacterial DNA (bDNA) acts as one of triggers of SIRS, anti-bDNA strategies should play an important role in preventing and curing SIRS. Serotypes 2 and 5 adenoviral DNA (Adv2, 5 DNA), which are nonstimulatory, can inhibit the activations induced by bDNA. The present study aims at getting potent neutralizing CpG oligonucleotides (CpG-N ODN) from the structures of Adv2, 5 DNA.Methods CD Sequences of Adv2, 5, 12 DNA and Escherichia coli DNA (EC DNA)were from Pub-Med. Performed. After sequences of Adv2, 5, 12 DNA and EC DNA were analyzed using three softwares such as BioEdit, initial putative CpG-N ODNs were designed. Ten putative CpG-N ODNs were selected and synthesized and investigated. Their abilities to inhibit TNF- release from hPBMC induced by CpG-S ODN was observed. Based on the above results, the putative CpG-N ODN were redesigned according to the relationships between the structure and free energy using RNAstructure software. Eleven putative CpG-N ODNs were synthesized and screened. (3) The most active CpG-N ODN208 was selected for detailed study. The time-effect relationship of ODN208 on TNF release from hPBMC induced by CpG-S ODN, and protection on mice challenged with CpG-S ODN were investigated.Results Nineteen specific CpG motifs and 12-nucleotide sequences with the specific CpG motif core in Adv2, 5 DNA were identified. But they didn't have the activity of CpG-N ODN after screened. (2) After redesign, six CpG-N ODNs were confirmed. Among these six CpG-N ODNs, CpG-N ODN208 was the strongest. It could inhibit TNF-a release from hPBMC induced by CpG-S ODN in a time-dependent manner. In vivo study, CpG-N ODN208 could markedly protect mice from lethal challenge by CpG-S ODNwithin seven days. The mortalities declined from ninety percent (9/10) to sixty percent (6/10).Conclusions We got six CpG-N ODNs with activity to inhibit TNF release from hPBMC induced by CpG-S ODN. CpG-N ODN208 could markedly protect mice from lethal challenge by CpG-S ODN. |
