“…As the mode of immunomodulatory action is likely to be independent of interactions with cell membranes, the issues of hemolytic activity and cytotoxicity toward mammalian cells are minimized, as supported by the minimal toxicity of peptide IDR-1 compared with natural cathelicidins like LL-37 (16,19). Furthermore, the many positive feedback systems that operate in the regulation of immune responses allow an immunomodulatory treatment to have wider effects on the outcome of infection than those of a microbicidal drug (20,21), and, indeed, IDR-1 has shown broad-spectrum protective activity in many models of infection (16) (R. E. W. Hancock, unpublished observations). Importantly, many host defense peptides combine both anti-infective and anti-inflammatory activities, and thus, IDR-1 therapy is not associated with risks of inflammatory tissue damage, as is often the case with other immunostimulatory treatments.…”