A novel function of phosphorothioate oligodeoxynucleotides as chemoattractants for primary macrophages.
Phosphorothioate cytosine-guanine oligodeoxynucleotides (CpG PS-ODNs) has been reported to induce Th1 immune responses against coadministered Ags more efficiently than phosphodiester CpG ODNs (CpG PO-ODNs). Here, we demonstrated that PS-ODNs, but not PO-ODNs, have a chemotactic effect on primary macrophages, which is independent of the CpG motif. In addition, the conjugation of a hexameric dG run (dG(6) run) at the 3' terminus reduced the concentration required for the optimal chemotactic activity of PS-ODNs by approximately 10-fold. Endosomal maturation blockers, such as monensin and chloroquine, inhibited the chemotactic effect of PS-ODNs. The inhibition of the activities of p38 mitogen-activated protein (MAP) kinase, and extracellular signal-related kinases (ERKs) as well as phosphoinositide 3-kinase with their specific inhibitors also resulted in suppressing the chemotaxis of primary macrophages induced by PS-ODNs. These results indicate that the PS-ODN-mediated chemotaxis requires the activation of ERKs, p38 MAP kinase, and phosphoinositide 3-kinase as well as endosomal maturation. In addition, the phosphorylations of the p38 MAP kinase, ERKs, and protein kinase B, Akt, were induced by PS-ODN, which were further enhanced by the presence of both a dG(6) run and CpG motifs. Our findings suggest that the chemotactic activity of PS-ODNs may be one of the mechanisms by which PS-ODNs exhibit stronger immunomodulatory activities than PO-ODNs in vivo.
Baek
K H
KH
National Research Laboratory of DNA Medicine, Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Korea.
Ha
S J
SJ
Sung
Y C
YC
D000818:Animals; D001483:Base Sequence; D002630:Chemotactic Factors / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D018899:CpG Islands; D005260:Female; D066298:In Vitro Techniques; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000201:enzymology / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction; D013873:Thionucleotides / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology
D002630:Chemotactic Factors; D020928:Mitogen-Activated Protein Kinases; D009838:Oligodeoxyribonucleotides; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D013873:Thionucleotides