In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

Q: We determined the interferon-␥ (IFN-␥) cDNA sequence from three porcine breeds, Duroc, Landrance/Duroc hybrid, and Landrance breeds. Five single nucleotide polymorphisms (SNPs) of porcine IFN-␥ (PoIFN-␥) were identified, respectively, at positions 269 (A/G), 376 (C/T), 426 (T/C), and 465 (T/C) of the coding sequence in Landrance/Duroc hybrid, and at position 251 (A/G) in Landrance breed. Among them, A269G and A251G polymorphisms resulted in Q67R and K61R replacements in the mature protein. PoIFN-␥ cDNAs of Duroc breed (PoIFN-␥-W) and Landrance/Duroc hybrid (PoIFN-␥-M), which, respectively, encoded Q67 and R67, were introduced into a prokaryotic expression vector pET32 to express recombinant PoIFN-␥-W (rPoIFN-␥-W) and rPoIFN-␥-M protein variants in Escherichia coli. The identity of both protein variants was further confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We then compared bioactivities of these two recombinant proteins. Although both recombinant protein variants exhibited comparable activities in antiproliferation of PK-15 cells and in nitric oxide (NO) induction of porcine peripheral monocytes, antiviral activity of rPoIFN-␥-W protein was significantly higher (P < 0.001) than that of rPoIFN-␥-M protein in a plaque inhibition assay using pseudorabies virus (PRV). IC50 values of rPoIFN-␥-W and rPoIFN-␥-M protein in anti-PRV assay were determined as 5.3 ± 1.3 and 9.3 ± 4.3 nM, respectively. In conclusion, we have identified five novel SNPs in PoIFN-␥ cDNA, including two missense polymorphisms that result in Q67R and K61R replacements. Our results further demonstrate that Q67R can markedly reduce antiviral activity of the PoIFN-␥ protein. This is the first report that shows the functional SNP in the coding region of IFN-␥. In the future, it is imperative to determine whether Q67R replacement in IFN-␥ may have disease association.

A: A missense polymorphism in porcine interferon-␥ cDNA affects antiviral activity of the protein variant
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Q: Influenza infection is a major cause of morbidity and mortality worldwide, especially during pandemics outbreaks. Emerging data indicate that phase II antioxidant enzyme pathways could play a role in virusassociated inflammation and immune clearance. While Nrf2-dependent gene expression is known to modify inflammation, a mechanistic role in viral susceptibility and clearance has yet to be elucidated. Therefore, we utilized differentiated human nasal epithelial cells (NEC) and an enzymatic virus-like particle entry assay, to examine the role Nrf2-dependent gene expression has on viral entry and replication. Herein, lentiviral vectors that express Nrf2-specific short hairpin (sh)-RNA effectively decreased both Nrf2 mRNA and Nrf2 protein expression in transduced human NEC from healthy volunteers. Nrf2 knockdown correlated with a significant increase in influenza virus entry and replication. Conversely, supplementation with the potent Nrf2 activators sulforaphane (SFN) and epigallocatechin gallate (EGCG) significantly decreased viral entry and replication. The suppressive effects of EGCG on viral replication were abolished in cells with knocked-down Nrf2 expression, suggesting a causal relationship between the EGCG-induced activation of Nrf2 and the ability to protect against viral infection. Interestingly, the induction of Nrf2 via nutritional supplements SFN and EGCG increased antiviral mediators/responses: RIG-I, IFN-β, and MxA at baseline in the absence of infection. Our data indicate that there is an inverse relationship between the levels of Nrf2 expression and the viral entry/ replication. We also demonstrate that supplementation with Nrf2-activating antioxidants inhibits viral replication in human NEC, which may prove to be an attractive therapeutic intervention. Taken together, these data indicate potential mechanisms by which Nrf2-dependent gene expression regulates susceptibility to influenza in human epithelial cells.

A: Nrf2 expression modifies influenza A entry and replication in nasal epithelial cells ☆
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Q: The enzymatic activity of the SARS coronavirus main proteinase dimer was characterized by a sensitive, quantitative assay. The new, fluorogenic substrate, (Ala-Arg-Leu-Gln-NH) 2 -Rhodamine, contained a severe acute respiratory syndrome coronavirus (SARS CoV) main proteinase consensus cleavage sequence and Rhodamine 110, one of the most detectable compounds known, as the reporter group. The gene for the enzyme was cloned in the absence of purification tags, expressed in Escherichia coli and the enzyme purified. Enzyme activity from the SARS CoV main proteinase dimer could readily be detected at low pM concentrations. The enzyme exhibited a high K m , and is unusually sensitive to ionic strength and reducing agents.

A:
Enzymatic activity of the SARS coronavirus main proteinase dimer
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