MyD88 and not TRIF knockout is sufficient to abolish LPS-induced inflammatory responses in bone-derived macrophages

Macrophages play an important role in the response to infection and/or repair of injury in tissues. To examine the NF-kappa B pathway in response to an inflammatory stimulus, we used wild-type bone-marrow-derived macrophages (BMDMs) or BMDMs with knockout (KO) of myeloid differentiation primary response 88 (MyD88) and/or Toll/interleukin-1 receptor domain-containing adapter-inducing interferon-beta (TRIF) via CRISPR/Cas9. Following treatment of BMDMs with lipopolysaccharide (LPS) to induce an inflammatory response, translational signalling of NF-kappa B was quantified via immunoblot and cytokines were measured. Our findings reveal that MyD88 KO, but not TRIF KO, decreased LPS-induced NF-kappa B signalling, and 10% expression of basal MyD88 expression was sufficient to partially rescue the abolished inflammatory cytokine secretion observed upon MyD88 KO.

Automated summary

Macrophages are important for the response to infection and/or tissue repair. In this study, the NF-kappa B pathway in response to an inflammatory stimulus was examined using different types of macrophages. The results show that MyD88 knockout decreases the signaling of NF-kappa B, and partial restoration of cytokine secretion is observed with partial expression of MyD88.