Description
Loxoribine is a guanosine derivative and an agonist of toll-like receptor 7 (TLR7). It is selective for TLR7 over other human TLRs in a cell-based reporter assay at 1 mM.. Loxoribine induces proliferation, increases the antibody response to sheep red blood cells, and activates natural killer cell activity against Yac-1 lymphoma cells in murine splenocyte cultures (EC
50s = 10-50, 3-20, and 13-22 μM, respectively). Loxoribine (250 μM) increases production of IL-12, IL-23, IL-27, and IL-10 by human monocyte-derived dendritic cells (MoDCs). Loxoribine-treated MoDCs induce higher levels of IL-17 and IFN-γ secretion by co-cultured allogeneic CD4
+ T cells compared to control MoDCs. Loxoribine (120 mg/kg) reduces the number of pulmonary metastases in the B16 mouse model of melanoma, an effect enhanced by co-administration of IL-2, and exhibits adjuvant activity in mice immunized with a B16 tumor vaccine.
Chemical Properties
White Solid
Uses
Small-molecule immunostimulants
Uses
Loxoribine is a selective toll-like receptor 7 (TLR7) agonist that activates immune cells and increases cytokine production.
Uses
7-Allyl-7,8-dihydro-8-oxoguanosine (Loxoribine) is a small-molecule immunostimulant. Loxoribine is a toll-like receptor 7 (TLR7) agonist; induces immune cell activation and increases cytokine product
ion. Loxoribine displays antitumor and antiviral activity in various animal models.
Biological Activity
Toll-like receptor 7 (TLR7) agonist; induces immune cell activation and increases cytokine production. Displays antitumor and antiviral activity in various animal models.
in vivo
Loxoribine (2 mg; s.c.or i.v.) activates murine natural killer (NK) cells in vivo[3].
| Animal Model: | 8-12 weeks male CBA/J mice[3] |
| Dosage: | 2 mg |
| Administration: | Subcutaneous or intravenous injection |
| Result: | activates murine natural killer (NK) cells in vivo. |
References
[1] FLORIAN HEIL. The Toll-like receptor 7 (TLR7)-specific stimulus loxoribine uncovers a strong relationship within the TLR7, 8 and 9 subfamily[J]. European Journal of Immunology, 2003, 33 11: 2987-2997. DOI:
10.1002/eji.200324238[2] GOODMAN M G. A new approach to vaccine adjuvants. Immunopotentiation by intracellular T-helper-like signals transmitted by loxoribine.[J]. Pharmaceutical biotechnology, 1995, 6: 581-609.
[3] MARÍA V GIRART. Engagement of TLR3, TLR7, and NKG2D regulate IFN-gamma secretion but not NKG2D-mediated cytotoxicity by human NK cells stimulated with suboptimal doses of IL-12.[J]. Journal of immunology, 2007, 179 6: 3472-3479. DOI:
10.4049/jimmunol.179.6.3472[4] CAMERON R STEWART. Toll-like receptor 7 ligands inhibit influenza A infection in chickens.[J]. Journal of Interferon and Cytokine Research, 2012, 32 1: 46-51. DOI:
10.1089/jir.2011.0036[5] CHENCHEN WANG. The TLR7 agonist induces tumor regression both by promoting CD4⁺T cells proliferation and by reversing T regulatory cell-mediated suppression via dendritic cells.[J]. Oncotarget, 2015: 1779-1789. DOI:
10.18632/oncotarget.2757
