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.
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Question: Early innate and cell-intrinsic responses are essential to protect host cells against pathogens. In turn, viruses have developed sophisticated mechanisms to establish productive infections, counteracting the host innate immune responses. Increasing evidence indicates that these antiviral factors may have a dual role by directly inhibiting viral replication, as well as by sensing and transmitting signals to induce antiviral cytokines. Recent studies have pointed at new, unappreciated mechanisms of viral evasion of host innate protective responses including manipulating the host ubiquitin system. Viral inhibition of antiviral factors by ubiquitin-dependent degradation is emerging as critical evasion mechanism of the antiviral response. In addition, recent studies have uncovered new mechanisms by which viral encoded proteins inhibit ubiquitin and ubiquitin-like modification of host proteins involved innate immune signaling pathways. Here we discuss recent findings and novel strategies that viruses have developed to counteract these early innate antiviral defenses. Early events in viral infection include attachment to the host cell membrane and entry, release of the viral RNA, DNA, and protein complexes into the cytoplasm of the cell and early recognition by the host innate immune system. At each of these steps, host cells have developed mechanisms to limit virus infection. In turn, viruses have rapidly evolved to counteract host defenses by different mechanisms. Many recent studies have pointed at the importance of cell type and host specific expression of antiviral factors as critical for

Answer: Viral evasion mechanisms of early antiviral responses involving regulation of ubiquitin pathways NIH Public Access


Question: 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.

Answer: A missense polymorphism in porcine interferon-␥ cDNA affects antiviral activity of the protein variant


Question: Background: The outcome of virus infection depends from the precise coordination of viral gene expression and genome replication. The ability to control and regulate these processes is therefore important for analysis of infection process. Viruses are also useful tools in bio-and gene technology; they can efficiently kill cancer cells and trigger immune responses to tumors. However, the methods for constructing tissue-or cell-type specific viruses typically suffer from low target-cell specificity and a high risk of reversion. Therefore novel and universal methods of regulation of viral infection are also important for therapeutic application of virus-based systems. Methods: Aberrantly spliced introns were introduced into crucial gene-expression units of adenovirus vector and alphavirus DNA/RNA layered vectors and their effects on the viral gene expression, replication and/or the release of infectious genomes were studied in cell culture. Transfection of the cells with splice-switching oligonucleotides was used to correct the introduced functional defect(s). Results: It was demonstrated that viral gene expression, replication and/or the release of infectious genomes can be blocked by the introduction of aberrantly spliced introns. The insertion of such an intron into an adenovirus vector reduced the expression of the targeted gene more than fifty-fold. A similar insertion into an alphavirus DNA/RNA layered vector had a less dramatic effect; here, only the release of the infectious transcript was suppressed but not the subsequent replication and spread of the virus. However the insertion of two aberrantly spliced introns resulted in an over one hundred-fold reduction in the infectivity of the DNA/RNA layered vector. Furthermore, in both systems the observed effects could be reverted by the delivery of splice-switching oligonucleotide(s), which corrected the splicing defects. Conclusions: Splice-switch technology, originally developed for genetic disease therapy, can also be used to control gene expression of viral vectors. This approach represents a novel, universal and powerful method for controlling gene expression, replication, viral spread and, by extension, virus-induced cytotoxic effects and can be used both for basic studies of virus infection and in virus-based gene-and anti-cancer therapy.

Answer:
Novel viral vectors utilizing intron splice- switching to activate genome rescue, expression and replication in targeted cells