RESUMO
Targeted activation of the NAIP-NLRC4 inflammasome has proven very useful in the study of pyroptosis. FlaTox and derivative LFn-NAIP-ligand cytosolic delivery systems offer a unique opportunity to interrogate both ligand recognition and downstream effects of the NAIP-NLRC4 inflammasome pathway. Here we describe how to stimulate the NAIP-NLRC4 inflammasome in vitro and in vivo. We describe experimental setup and specific considerations for treatment of macrophages in vitro and in vivo injections using a murine model of systemic inflammasome activation. The in vitro readouts of inflammasome activation propidium iodide uptake and lactate dehydrogenase (LDH) release as well as the in vivo readouts of hematocrit and body temperature measurement are described.
Assuntos
Proteínas Reguladoras de Apoptose , Inflamassomos , Animais , Camundongos , Inflamassomos/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Piroptose , Ligantes , Macrófagos/metabolismo , Proteínas de Ligação ao Cálcio/metabolismoRESUMO
The Nod-like Receptor (NLR) apoptosis inhibitory proteins (NAIPs) are cytosolic receptors that sense cytosolic bacterial proteins. NAIP ligation induces its association with NLRC4, leading to the assembly of the NAIP/NLRC4 inflammasome, which induces the activation of the caspase-1 protease. Caspase-1 then cleaves pro-interleukin (IL)-1ß, pro-IL-18, and gasdermin D and induces a form of pro-inflammatory cell death, pyroptosis. These processes culminate in host defense against bacterial infection. Here we describe methods for activating NAIP/NLRC4 inflammasome signalling in human and murine macrophages and quantifying inflammasome-induced cell death.