C-Class CpG ODN: sequence requirements and characterization of immunostimulatory activities on mRNA level.
Synthetic oligodeoxynucleotides (ODN) containing unmethylated deoxycytosine-deoxyguanosine (CpG) motifs are very potent inducers of the innate immune system, mimicking the effects of bacterial DNA. CpG ODN are recognized by Toll-like receptor 9 (TLR9). Three classes of TLR9 agonists have been described: B-Class CpG ODN that induce strong B- and NK-cell activation and A-Class ODN that induce very high levels of IFN-alpha by plasmacytoid dendritic cells. The recently described C-Class ODN combine most efficiently properties of A- and B-Class ODN in that they induce strong B-cell activation comparable to B-Class ODN together with IFN-alpha secretion comparable to A-Class ODN. Here, we investigate sequence requirements of C-Class ODN regarding optimal IFN-alpha secretion. Sequence as well as backbone modifications like 2'-O-methyl modifications especially in the 5' part of the ODN influence IFN-alpha-producing capacity. Kinetic studies on mRNA level for CD69, IFN-gamma, IP-10 and IL-18 by semi-quantitative PCR demonstrated differences in mRNA transcription for some cytokines suggesting different regulatory mechanisms for different ODN classes. High amounts of IP-10 mRNA and protein as well as up-regulation of IL-18 mRNA were observed especially for the A- and C-Classes. According to these data, C-Class ODN can be described as strong Th1 inducers with the stimulation of type I and II interferon as well as IP-10 production and strong NK activation. These characteristics can be availed to induce potent anti-tumor or anti-viral effects. Consequently, C-Class CpG ODN represent ideal drug candidates for anti-viral and/or anti-tumor therapy.
Jurk
Marion
M
Coley Pharmaceutical GmbH, Elisabeth-Selbert-Str. 9, D-40764 Langenfeld, Germany. mjurk@coleypharma.com
Schulte
Bettina
B
Kritzler
Andrea
A
Noll
Bernhard
B
Uhlmann
Eugen
E
Wader
Tanja
T
Schetter
Christian
C
Krieg
Arthur M
AM
Vollmer
Jörg
J
D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D054357:Chemokine CXCL10; D019743:Chemokines, CXC / Q000378:metabolism; D003470:Culture Media; D015536:Down-Regulation; D006801:Humans; D016898:Interferon-alpha / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D007700:Kinetics; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors; D015854:Up-Regulation; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D054357:Chemokine CXCL10; D019743:Chemokines, CXC; D003470:Culture Media; D016898:Interferon-alpha; D007371:Interferon-gamma; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors; D000099192:CD69 Antigens; C408982:CPG-oligonucleotide; C495371:TLR9 protein, human