Cross-Species Genome-Wide Analysis Reveals Molecular and Functional Diversity of the Unconventional Interferon-? Subtype

Shields, Lauren E.; Jennings, Jordan; Liu, Qinfang; Lee, Jinhwa; Ma, Wenjun; Blecha, Frank; Miller, Laura C.; Sang, Yongming

Based on fragmentary information, previous studies on IFN molecular evolution posited a general linear increase of IFNcoding genes during vertebrate evolution and a dramatic acceleration after the emergence of intronless IFN genes, presumably in reptiles (12, 40) . We have examined IFN genes (13, 24) . Data are means ± SE; n = 3; *p < 0.05 relative to the control. . IFN peptides were collected and partially purified using two Centricon ® centrifugal filters (10 and 50 k NMWL, Millipore, Billerica, MA). Concentrated IFN-peptides were subjected to gel electrophoresis and stained with a bio-safe Coomassie Blue G-250 solution. Shown are peptide bands of most IFN-α/β subtypes, IFN-ω1, and IFN-ω5. Note that the bands of IFN-α6, IFN-α9, and IFN-β are smeared and have apparent molecular weights higher than expected values (∼20 kDa), which might reflect posttranslational modification such as N-glycosylation (13, 23) . (B) Porcine IFN-ω peptides exert broad and high antiviral activity against PRRSV and influenza A virus in cells from pigs, monkeys, humans, and mice. The antiviral activity of IFN peptides was titrated as described (7), except viruses were quantified using fluorescence-labeling (PRRSV-DsRed and FITC-immunostaining for influenza A nucleoprotein) in the susceptible cells of monkey MARC-145, porcine macrophages (MΦs) and PK-15, human A549, and mouse Mode-K and NIH3T3 (13, 24) . A PRRSV-P129 strain, and three influenza strains, pH1N1, WSN, and KS07 were used. a,b; p < 0.001, 0.01 to IFN-α1, respectively. Data are means ± SE; n = 5.