CL307

TLR7 Agonist - Base analog

CL307 is a potent and specific Toll-like receptor 7 (TLR7) agonist. It was generated by covalently linking a spermine to the adenine analog CL264, a TLR7 agonist developed by InvivoGen. Coupling with spermine enhances cellular uptake by endocytosis [1, 2] and the subsequent delivery to TLR7.

TLR7 is an innate immune sensor expressed on the surface of endosomes. It recognizes viral single-stranded ribonucleic acid (ssRNA) as its natural ligand and also small synthetic molecules such as imidazoquinolines and nucleoside analogs [3]. Activation of TLR7 leads to NF-κB/AP1- and interferon (IFN) regulatory factor-mediated production of type I IFNs and pro-inflammatory cytokines [3].

Notably, titration experiments with InvivoGen’s HEK-Blue™ hTLR7 cells, which stably express an NF-κB-inducible SEAP reporter gene and human TLR7, demonstrated that CL307 induces robust NF-κB activation at concentrations as low as 20 nM (10 ng/ml). Furthermore, it has been reported in the literature that CL307 induces the production of the pro‑inflammatory cytokine, interleukin-6, by peripheral blood mononuclear cells [1]. Importantly, CL307 is a TLR7-specific ligand that does not activate TLR8 even at high concentrations (>10 µg/ml).

Key Features of CL307:

• Potent and specific activator of human & murine TLR7
• Does not activate TLR8
• Each lot of CL307 is highly pure (≥95%) and functionally tested

Read our review on TLR7 and TLR8

References:

1. Järver P. et al., 2018. Single-stranded nucleic acids regulate TLR3/4/7 activation through interference with Clathrin-mediated endocytosis. Sci Rep. 8(1):15841.
2. Soulet D. et al., 2002. Role of endocytosis in the internalization of spermidine-C(2)-BODIPY, a highly fluorescent probe of polyamine transport. Biochem. J. 367:347-57.
3. Georg P. & Sander L.E., 2019. . Innate sensors that regulate vaccine responses. Curr. Op. Immunol. 59:31.

Specifications

Specificity: human/mouse TLR7 agonist

Synonym: N1-glycinyl [4-((6-amino-2- (butylamino)-8- hydroxy-9H- purin- 9-yl)methyl) benzoyl] spermine

Working concentration: 5 ng- 1 µg/ml (~10nM - 2 µM)

Formula: C₂₉H₄₇N₁₁O₃

Molecular weight: 597 g/mol

Solubility: 2 mg/ml in water

Quality control:

• Purity: ≥95% (UHPLC)
• Activation of TLR7 by CL307 has been validated using cellular assays.
• The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ hTLR2 and HEK-Blue™ hTLR4 cells.

Contents

• 500 µg CL307
• 1.5 ml sterile endotoxin-free water

Products are shipped at room temperature

Stored at -20°C.

Description

CL307 chemical structure

Details

HEK-Blue™ hTLR7 cells, which stably express an NF-κB-inducible SEAP reporter gene and human TLR7 were incubated in HEK-Blue™ Detection (a SEAP detection growth medium) and stimulated with increasing concentrations of the agonists indicated in the graph.
After 24h incubation, the levels of NF-κB-induced SEAP were determined by reading the OD at 655 nm.

RAW-Blue™ cells, which stably express an NF-κB-inducible SEAP reporter gene, were stimulated with 0.6 µg/ml of InvivoGen’s multi-PRR ligands complexed with 0.1 µg/ml HSV-60 (synthetic dsDNA).
After 24h incubation, the levels of NF-κB-induced SEAP were determined using QUANTI-Blue™, a SEAP detection reagent.