PASylation of IL-1 receptor antagonist (IL-1Ra) retains IL-1 blockade and extends its duration in mouse urate crystal-induced peritonitis [Protein Structure and Folding]

Interleukin-1 (IL-1) is a key mediator of inflammation and immunity. Naturally-occurring IL-1 receptor antagonist (IL-1Ra) binds and blocks the IL-1 receptor-1 (IL-1R1), preventing signaling. Anakinra, a recombinant form of IL-1Ra, is used to treat a spectrum of inflammatory diseases. However, anakinra is rapidly cleared from the body and requires daily administration. To create a longer-lasting alternative, PASylated IL-1Ra (PAS–IL-1Ra) has been generated by in-frame fusion of a long, defined-length, N-terminal Pro/Ala/Ser (PAS) random-coil polypeptide with IL-1Ra. Here, we compared the efficacy of two PAS–IL-1Ra molecules, PAS600–IL-1Ra and PAS800–IL-1Ra (carrying 600 and 800 PAS residues, respectively), with that of anakinra in mice. PAS600–IL-1Ra displayed markedly extended blood plasma levels 3 days post-administration, whereas anakinra was undetectable after 24 h. We also studied PAS600–IL-1Ra and PAS800–IL-1Ra for efficacy in monosodium urate (MSU) crystal-induced peritonitis. 5 days post-administration, PAS800–IL-1Ra significantly reduced leukocyte influx and inflammatory markers in MSU-induced peritonitis, whereas equimolar anakinra administered 24 h before MSU challenge was ineffective. The 6-h pretreatment with equimolar anakinra or PAS800–IL-1Ra before MSU challenge similarly reduced inflammatory markers. In cultured A549 lung carcinoma cells, anakinra, PAS600–IL-1Ra, and PAS800-IL-Ra reduced IL-1α–induced IL-6 and IL-8 levels with comparabl...
Source: Journal of Biological Chemistry - Category: Chemistry Authors: Tags: Immunology Source Type: research