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]: Given the high mortality rate (>50%) and potential danger of intrapersonal transmission, highly pathogenic avian influenza (HPAI) H5N1 epidemics still pose a significant threat to humans. T cells, which participate on the front line of the host immune defense, demonstrate both innate, and adaptive characteristics in their immune response and have potent antiviral activity against various viruses. However, the roles of T cells in HPAI H5N1 viral infection remain unclear. In this study, we found that T cells provided a crucial protective function in the defense against HPAI H5N1 viral infection. HPAI H5N1 viruses could directly activate T cells, leading to enhanced CD69 expression and IFN- secretion. Importantly, we found that the trimer but not the monomer of HPAI H5N1 virus hemagglutinin (HA) proteins could directly activate T cells. HA-induced T cell activation was dependent on both sialic acid receptors and HA glycosylation, and this activation could be inhibited by the phosphatase calcineurin inhibitor cyclosporin A but not by the phosphatidylinositol 3-kinase (PI3-K) inhibitors wortmannin and LY294002. Our findings provide a further understanding the mechanism underlying T cell-mediated innate and adoptive immune responses against HPAI H5N1 viral infection, which helps to develop novel therapeutic strategies for the treatment of H5N1 infection in the future.
[A]: T Cells Provide Protective Function in Highly Pathogenic Avian H5N1 Influenza A Virus Infection

[Q]: 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
[A]: Viral evasion mechanisms of early antiviral responses involving regulation of ubiquitin pathways NIH Public Access

[Q]: The yeast Kre2p/Mntlp cxl,2-mannosyltransferase is a type II membrane protein with a short cytoplasmic amino terminus, a membrane-spanning region, and a large catalytic luminal domain containing one N-glycosylation site. Anti-Kre2p/Mntlp antibodies identify a 60-kD integral membrane protein that is progressively N-glycosylated in an MNNl-dependent manner. Kre2p/Mntlp is localized in a Golgi compartment that overlaps with that containing the medial-Golgi mannosyltransferase Mnnlp, and distinct from that including the late Golgi protein Kexlp. To determine which regions of Kre2p/Mntlp are required for Golgi localization, Kre2p/Mntlp mutant proteins were assem-bled by substitution of Kre2p domains with equivalent sequences from the vacuolar proteins DPAP B and Pho8p. Chimeric proteins were tested for correct topology, in vitro and in vivo activity, and were localized intracellularly by indirect immunofluorescence. The resuits demonstrate that the NH2-terminal cytoplasmic domain is necessary for correct Kre2p Golgi localization whereas, the membrane-spanning and stem domains are dispensable. However, in a test of targeting sufficiency, the presence of the entire Kre2p cytoplasmic tail, plus the transmembrane domain and a 36-amino acid residue luminal stem region was required to localize a Pho8p reporter protein to the yeast Golgi. T HE Golgi apparatus plays a fundamental role in glycan processing and sorting of newly synthesized proteins in the secretory pathway of eukaryotic cells. The Golgi apparatus of a typical mammalian cell is composed of a polarized stack of membranous saccules that are differentiated into functionally distinct subcompartments. After the addition of core N-linked sugar moieties in the endoplasmic reticulum, glycoproteins proceed through the cis-Golgi network, the cis-, medial-, and transcisternae, and the trans-Golgi network, where further modifications take place. These include the addition of O-linked sugars and the elaboration, in a protein-specific manner, of complex N-linked carbohydrate structures. The Golgi apparatus also constitutes a major organelle responsible for protein trafficking where particular proteins are directed to precise cellular locations. Two specific Golgi subcompartments have been found to be involved in protein sorting. The cis-Golgi network constitutes the site from which many resident ER proteins are retrieved, and the main function of the TGN is to direct glycoproteins exiting the Golgi complex to either the lysosome or the cell surface (
[A]:
Localization and Targeting of the Saccharomyces cerevisiae Kre2p/Mnt lp oL 1,2-Mannosyltransferase to a medial.Gol Compartment