Novel cyclic peptides containing a γ-glutamyl residue induce IL-1 secretion from human peripheral blood mononuclear cells

Three synthetic cyclic tripeptides, each containing a γ-glutamyl residue were shown to induce the production of interleukin-1 (IL-1) from human peripheral blood mononuclear cells (PBMC). In addition, the cyclic peptide cyclo[Glu(Lys-β-Ala-)-OH] (cG-2) was capable of eliciting IL-1 production from PBMC dose-dependently.