E6446 dihydrochloride (E-6446 dihydrochloride)

Cell experiment:

E6446 is assayed for the suppression of BALB/c mouse spleen interleukin-6 (IL-6) production in response to stimulation by oligonucleotide CpG1668. E6446 is added to dissociated splenocytes (5 × 105 per well in complete RPMI/10% fetal bovine serum in a 96-well plate) before addition of TLR agonists. Cells are stimulated for 72 hours, and supernatants are removed for ELISA analysis of IL-6. Mouse bone marrow-derived dendritic cells (BMDCs) are generated by culturing BALB/c marrow cells in RPMI containing 100 ng/mL Flt3 ligand for 7 days. Cells (1 × 105) in 50 μL are assayed for IL-6 production after overnight or 24-hour stimulation with various TLR ligands. For studies using human peripheral blood mononuclear cells, Ficoll-separated mononuclear cells are isolated from healthy volunteer donors, washed, and plated with stimulatory oligonucleotide CpG2216 in complete RPMI for 72 hours. Interferon in supernatant is quantified by ELISA[1].

Animal experiment:

Mice[1]MRL/lpr mice are dosed orally five times a week with 20 or 60 mg/kg E6446 or 60 mg/kg hydroxychloroquine beginning at 5 weeks of age. Cytoxan is administered at 50 mg/kg i.p. every 10 days. A serum sample is taken immediately before the beginning of treatment to monitor changes in autoreactive antibodies. Subsequently, serum samples are collected approximately monthly and analyzed for anti-dsDNA by ELISA after 1:500 dilution. Body weights and urine samples are taken at the same interval, and proteinuria is assessed by ChemStrips. Anti-nuclear antibodies (ANA) are assessed using commercially available HEp2 slide kits, with serum diluted to 1:100 in kit buffer. ANA scores are read blinded[1].

References:

[1]. Lamphier M, et al. Novel small molecule inhibitors of TLR7 and TLR9: mechanism of action and efficacy in vivo. Mol Pharmacol. 2014 Mar;85(3):429-40.
[2]. Franklin BS, et al. Therapeutical targeting of nucleic acid-sensing Toll-like receptors prevents experimental cerebral malaria. Proc Natl Acad Sci U S A. 2011 Mar 1;108(9):3689-94.