ODN 2395 FITC

FITC labeled CpG oligonucleotide - Human / Mouse TLR9 ligand

CpG ODNs are synthetic oligonucleotides that contain unmethylated CpG dinucleotides in particular sequence contexts (CpG motifs). These CpG motifs are present at a 20-fold greater frequency in bacterial DNA  compared to mammalian DNA.

They have been shown to induce a coordinated   set of immune responses based on the activation of immune cells   primarily involved in the recognition of these molecules.

ODN 2395 FITC is a C-class CpG ODN specific for human / mouse TLR9. ODN 2395  FITC can  be used to evaluate CpG ODN cellular uptake and localization  by  confocal laser-scanning microscopy (excitation 495 nm, emission 520  nm)  or flow cytometry.

Specifications

Specificity: human/murine TLR9 agonist

Working concentration: 1-5 μM

ODN 2395 sequence
5’-tcgtcgttttcggcgc:gcgccg-3’ (22 mer)
Note: Bases are phosphorothioate (nuclease resistant), palindrome is underlined.

Spectral Properties of FITC
Excitation λ max: 495 nm
Emission λ max: 520 nm

Quality control:

• TLR9 activity has been tested using HEK-Blue™ TLR9 cells.
• The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK-Blue™ TLR4 cells.

Contents

• 50 μg (6.5 nmol) lyophilized ODN 2395 labeled with FITC at the 3’ terminus
• 2 ml sterile endotoxin-free water

ODN2395 FITC is shipped at room temperature.

Upon receipt, store ODN2395 FITC at -20 °C.

Description

CpG ODNs are synthetic oligonucleotides that contain unmethylated CpG dinucleotides in particular sequence contexts (CpG motifs) [1].
These CpG motifs are present at a 20-fold greater frequency in bacterial DNA compared to mammalian DNA. CpG ODNs are recognized by Toll-like receptor 9 (TLR9) leading to strong immunostimulatory effects [2].

Three types of stimulatory CpG ODNs have been identified, types A, B and C, which differ in their immune-stimulatory activities [3-4]. Type A CpG ODNs are characterized by a phosphodiester central CpG-containing palindromic motif and a phosphorothioate 3’ poly-G string. They induce high IFN-α production from plasmacytoid dendritic cells (pDC) but are weak stimulators of TLR9-dependent NF-kB signaling. Type B CpG ODNs contain a full phosphorothioate backbone with one or more CpG dinucleotides. They strongly activate B cells but stimulate weakly IFN-α secretion. Type C CpG ODNs combine features of both types A and B. They contain a complete phosphorothioate backbone and a CpG-containing palindromic motif. Type C CpG ODNs are potent inducers of IFN-α from pDC and strong B cell activators [5, 6].

ODN 2395 is a type C CpG ODN [7].

References:

1. Krieg AM. et al., 1995. CpG motifs in bacterial DNA trigger direct B-cell activation. Nature, 374(6522):546-9.
2. Bauer S. et al., 2001. Human TLR9 confers responsiveness to bacterial DNA via species-specific CpG motif recognition. PNAS, 98(16):9237-42.
3. Krug A. et al., 2001. Identification of CpG oligonucleotide sequences with high induction of IFNalpha/ beta in plasmacytoid dendritic cells. Eur J Immunol, 31(7): 2154-63.
4. Marshall JD. et al., 2005. Superior activity of the type C class of ISS in vitro and in vivo across multiple species. DNA Cell Biol. 24(2):63-72.
5. Jurk M. et al., 2004. C-Class CpG ODN: sequence requirements and characterization of immunostimulatory activities on mRNA level. Immunobiology. 209(1-2):141-54.
6. Abel K. et al., 2005. Deoxycytidyl-deoxyguanosine oligonucleotide classes A, B, and C induce distinct cytokine gene expression patterns in rhesus monkey peripheral blood mononuclear cells and distinct alpha interferon responses in TLR9-expressing rhesus monkey plasmacytoid dendritic cells. Clin Diagn Lab Immunol. 12(5):606-21.
7. Roda JM. et al., 2005. CpG-containing oligodeoxynucleotides act through TLR9 to enhance the NK cell cytokine response to antibody-coated tumor cells. J Immunol. 175(3):1619-27. 6. Schindler U. & Baichwal VR., 1994. Three NF-kB binding sites in the human E-selectin gene required for maximal tumor necrosis factor alpha-induced expression. Mol Cell Biol, 14(9):5820-5831.