Fig. 2

Enhancement of TNF synthesis is dependent on the degree of phosphorothioate linkages and independent of the sequence

Human mononuclear cells (2.5 Mio/ml) were stimulated with 10 ng/ml LPS for 20 hr in the presence of the oligonucleotides indicated (all at 5 µM). No difference of TNF synthesis was found between the control with LPS alone (■) and in the presence of the partially modified oligonucleotide ODN 7pm (two phosphorothioate nucleotides at the 5′ and the 3′ end) and the unmodified oligonucleotide ODN 7um. LPS-stimulated TNF synthesis was enhanced only for the completely modified oligonucleotides ODN 7cm and ODN 19cm. Without LPS stimulation (□) only small induction occured in the presence of the completely modified oligonucleotides ODN 7cm and ODN 19cm, whereas TNF synthesis was at the detection limit in the presence of the partially and unmodified ODN 7. Results are given as means of three independent experiments. *p < 0.05; error bars = SEM.