FIG. 1.

The myxoma virus M013 fusion protein inhibits interleukin (IL)-1β secretion. (A) The native M013 protein from myxoma virus has been demonstrated to inhibit both nuclear factor (NF)-κB and NLRP3 inflammasome signaling pathways by interacting with key effector components. (B) Map of lentiviral vector delivering the TatM013 fusion gene. The M013 and TatM013 fusion genes were cloned in-frame with the 2A peptide and puromycin resistance (puroR) sequence. (C) Monocyte-derived THP-1 cells were transduced with a lentiviral vector delivering the M013-puroR fusion gene, the TatM013-puroR fusion, or the puroR gene alone as a control. Stably transduced cells were incubated with IFN-γ (4 hr) and lipopolysaccharide (LPS) (18 hr). Secreted IL-1β was quantified by ELISA. M013 protein was measured in cell extracts by Western blotting, and compared with tubulin control (inset) (n=3, average±SEM). (D) ARPE-19 cells were transduced with either the TatM013-puroR or puroR lentiviral vector. Stably transduced cells were incubated with 30 μM 4-hydroxynonenal (4-HNE, 18 hr). Secreted IL-1β was quantified by ELISA (n=3, average±SEM). ASC, apoptosis-associated speck-like protein containing a caspase recruitment domain; AmpR, ampicillin resistance gene; cPPT, central polypurine tract; EF1, elongation factor-1; HIV LTR, human immunodeficiency virus long terminal repeat; Iκ-B, inhibitor of NF-κB; IKKK, Iκ-B kinase kinase; n.s., not significant; ORI/Ori, origin of replication; RRE, Rev response element; RSV, Rous sarcoma virus; SV40, simian virus 40; TNF-α, tumor necrosis factor-α; WPRE, woodchuck hepatitis virus posttranscriptional regulatory element. *p≤0.05; ***p≤0.0001. Color images available online at www.liebertpub.com/hum