Small-molecule costimulatory blockade: Organic dye inhibitors of the CD40-CD154 interaction

Emilio Margolles-Clark, Oliver Umland, Norma S. Kenyon, Camillo Ricordi, Peter Buchwald

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


Costimulatory blockade is one of the most promising therapeutic targets in autoimmune diseases as well as in transplant recipients, and inhibition of the cluster of differentiation (CD)40-CD154 interaction, which is required for T cell activation and development of an effective immune response, is particularly promising in islet transplant recipients. Here, we report the ability of several small-molecule organic dyes to concentration dependently inhibit this interaction with IC50 values in the low-micromolar range. They were found to be considerably more active in inhibiting this interaction than the tumor necrosis factor (TNF)-R1-TNF-α or B cell-activating factor (BAFF)-R-BAFF interaction, which are members of the same family. They specifically inhibited CD154-induced cell responses in human B cells as well as in THP-1 myeloid cells, which can serve as surrogate dendritic cells, at concentrations well below their cytotoxic concentrations determined in the same cells. Flow cytometry experiments confirmed their ability to inhibit the CD154-induced, but not the Staphylococcus aureus Cowan I- or phorbol 12-myristate 13-acetate-induced increase in the surface expression of CD54, CD40, and major histocompatibility complex class II. Accordingly, these compounds can be useful not only for experimental investigations involving the inhibition of the CD40-CD154 costimulatory interaction but can also provide important structure-activity relationship information and can serve as the starting point of a targeted drug discovery program.

Original languageEnglish (US)
Pages (from-to)1133-1143
Number of pages11
JournalJournal of Molecular Medicine
Issue number11
StatePublished - Nov 2009


  • Azo dyes
  • CD40L
  • Direct red 80
  • Immune suppression
  • Protein-protein interaction
  • THP-1 cells

ASJC Scopus subject areas

  • Molecular Medicine
  • Drug Discovery
  • Genetics(clinical)


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