Immunostimulatory Properties of Phosphorothioate CpG DNA Containing Both 3'-5'- and 2'-5'-internucleotide Linkages
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Synthetic oligodeoxyribonucleotides containing CpG-dinucleotides (CpG DNA) in specific sequence contexts activate the vertebrate immune system. We have examined the effect of 3'-deoxy-2'-5'-ribonucleoside (3'-deoxynucleoside) incorporation into CpG DNA on the immunostimulatory activity. Incorporation of 3'-deoxynucleosides results in the formation of 2'-5'-internucleotide linkages in an otherwise 3'-5'-linked CpG DNA. In studies, both in vitro and in vivo, CpG DNA containing unnatural 3'-deoxynucleoside either within the CpG-dinucleotide or adjacent to the CpG-dinucleotide failed to induce immunostimulatory activity, suggesting that the modification was not recognized by the receptors. Incorporation of the same modification distal to the CpG-dinucleotide in the 5'-flanking sequence potentiated the immunostimulatory activity of the CpG DNA. The same modification when incorporated in the 3'-flanking sequence had an insignificant effect on immunostimulatory activity of CpG DNA. Interestingly, substitution of a 3'-deoxynucleoside in the 5'-flanking sequence distal to the CpG-dinucleotide resulted in increased IL-6 and IL-10 secretion with similar levels of IL-12 compared with parent CpG DNA. The incorporation of the same modification in the 3'-flanking sequence resulted in lower IL-6 and IL-10 secretion with similar levels of IL-12 compared with parent CpG DNA. These results suggest that site-specific incorporation of 3'-deoxynucleotides in CpG DNA modulates immunostimulatory properties.
The Evolution of Antisense Oligonucleotide Chemistry-A Personal Journey.
Agrawal S Biomedicines. 2021; 9(5).
PMID: 34063675 PMC: 8147625. DOI: 10.3390/biomedicines9050503.
Putta M, Bhagat L, Wang D, Zhu F, Kandimalla E, Agrawal S ACS Med Chem Lett. 2014; 4(2):302-5.
PMID: 24900663 PMC: 4027476. DOI: 10.1021/ml300482z.
Novel oligodeoxynucleotide agonists of TLR9 containing N3-Me-dC or N1-Me-dG modifications.
Putta M, Zhu F, Li Y, Bhagat L, Cong Y, Kandimalla E Nucleic Acids Res. 2006; 34(11):3231-8.
PMID: 16798912 PMC: 1904100. DOI: 10.1093/nar/gkl430.
Kandimalla E, Bhagat L, Li Y, Yu D, Wang D, Cong Y Proc Natl Acad Sci U S A. 2005; 102(19):6925-30.
PMID: 15860583 PMC: 1100782. DOI: 10.1073/pnas.0501729102.
Impact of site-specific nucleobase deletions on the arthritogenicity of DNA.
Bjersing J, Tarkowski A, Kandimalla E, Karlsson H, Agrawal S, Collins L Inflammation. 2004; 28(3):159-68.
PMID: 15527171 DOI: 10.1023/b:ifla.0000039562.30451.0a.