Document Report Card

ID: ALA2384907

Journal: J Med Chem

Title: Identification of substituted pyrimido[5,4-b]indoles as selective Toll-like receptor 4 ligands.

Authors: Chan M, Hayashi T, Mathewson RD, Nour A, Hayashi Y, Yao S, Tawatao RI, Crain B, Tsigelny IF, Kouznetsova VL, Messer K, Pu M, Corr M, Carson DA, Cottam HB.

Abstract: A cell-based high-throughput screen to identify small molecular weight stimulators of the innate immune system revealed substituted pyrimido[5,4-b]indoles as potent NFκB activators. The most potent hit compound selectively stimulated Toll-like receptor 4 (TLR4) in human and mouse cells. Synthetic modifications of the pyrimido[5,4-b]indole scaffold at the carboxamide, N-3, and N-5 positions revealed differential TLR4 dependent production of NFκB and type I interferon associated cytokines, IL-6 and interferon γ-induced protein 10 (IP-10) respectively. Specifically, a subset of compounds bearing phenyl and substituted phenyl carboxamides induced lower IL-6 release while maintaining higher IP-10 production, skewing toward the type I interferon pathway. Substitution at N-5 with short alkyl substituents reduced the cytotoxicity of the leading hit compound. Computational studies supported that active compounds appeared to bind primarily to MD-2 in the TLR4/MD-2 complex. These small molecules, which stimulate innate immune cells with minimal toxicity, could potentially be used as adjuvants or immune modulators.

CiteXplore: 23656327

DOI: 10.1021/jm301694x