A Small Molecule that Mimics the BB-Loop in the Toll/IL-1 Receptor Domain of MyD88 Attenuates Staphylococcal Enterotoxin B Induced Pro-Inflammatory Cytokine Production and Toxicity in Mice
Abstract
Toxic shock syndrome (TSS) is a clinical consequence of the profound amplification of host pro-inflammatory cytokine signaling that results from staphylococcal enterotoxin (SE) exposure. We recently reported that MyD88-/- mice were resistant to SEA or SEB toxic shock and displayed reduced levels of pro-inflammatory cytokines in their serum. Here we report that SEB stimulation of total mononuclear cells up-regulated MyD88 in monocytes and T cells. Further, MyD88 gene silencing in primary human cells using siRNA prevented SEB or SEB plus lipopolyaccharide (LPS) induction of interleukin-1 Beta (IL-1 Beta) transcriptional activation, suggesting that MyD88-mediated signaling is an essential component of SEB toxicity. We synthesized small molecules that mimic the conserved BBloop in the Toll/IL-1 receptor (TIR) domain of MyD88. In primary human cells, these mimetics attenuated SEB-induced proinflammatory cytokine production. SEB stimulation of primary cells with mimetic affected newly synthesized MyD88 and downstream signaling components. Furthermore, LPS-induced MyD88 signaling was likewise inhibited in a cell-based reporter assay. More importantly, administration of mimetic reduced cytokine responses and increased survivability in a murine SEB challenge model. Collectively, these results suggest that MyD88 BB-loop mimetics interfere with SEB-induced proinflammatory signaling and toxicity, thus offering a potential approach in the therapy of toxic shock.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2011
- Accession Number
- ADA546538
Entities
People
- Enrique Mann
- Gordon T. Ruthel
- Julius Rebek Jr.
- Kamal U. Saikh
- Lionel Moisan
- Mitra Rebek
- Robert G Ulrich
- Shahabuddin Alam
- Teri L. Kissner
Organizations
- United States Army Medical Research Institute of Infectious Diseases