Novel immunostimulatory phosphodiester oligodeoxynucleotides with CpT sequences instead of CpG motifs

► Identification of immunostimulatory phosphodiester bond CT-ODN from Staphylococcus aureus DNA. ► The PO-CT-ODN induces cytokine production in a TLR9-dependent manner. ► The PO-CT-ODN can act as an adjuvant for the induction of Ag-driven IgG production.