Immunomodulatory properties of DNA binding chicken cathelicidins on murine macrophage TLR9 activation.

Abstract

Cathelicidins have long been researched for protective capabilities against invading pathogens. Recently, they have been connected to the modulation of nucleic acid sensing by TLR receptors. However, little is known about their immunomodulatory influence on DNA-activated macrophages. In this study, we looked into the effects of DNA-binding cathelicidins on murine macrophages activated using physiological DNA or synthetic ODN. Our results show that chicken cathelicidin (CATH)-2 has a different effector function based on the type of DNA used. For ODN, it can enhance the activation of murine macrophages while with physiological DNA an anti-inflammatory function is observed. In addition, dextrorotary - CATH-2 was found to have a consistent anti-inflammatory effect on macrophages activated by all sources of DNA. Furthermore, truncated CATH-2 peptides, as well as CATH-1 were found to not affect DNA activated macrophages. These observations indicate that for DNA-binding cathelicidin research, the same cathelicidin might regulate immune responses differ depending on the cellular environment and DNA isotype.