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.

Ex Input:
Ebola virus (EBOV) disease can result in a range of symptoms anywhere from virtually asymptomatic to severe hemorrhagic fever during acute infection. Additionally, spans of asymptomatic persistence in recovering survivors is possible, during which transmission of the virus may occur. In acute infection, substantial cytokine storm and bystander lymphocyte apoptosis take place, resulting in uncontrolled, systemic inflammation in affected individuals. Recently, studies have demonstrated the presence of EBOV proteins VP40, glycoprotein (GP), and nucleoprotein (NP) packaged into extracellular vesicles (EVs) during infection. EVs containing EBOV proteins have been shown to induce apoptosis in recipient immune cells, as well as contain pro-inflammatory cytokines. In this manuscript, we review the current field of knowledge on EBOV EVs including the mechanisms of their biogenesis, their cargo and their effects in recipient cells. Furthermore, we discuss some of the effects that may be induced by EBOV EVs that have not yet been characterized and highlight the remaining questions and future directions. It is estimated that only approximately 20%-25% of GP products are the membrane-anchored GP 1,2 form, while the remaining 75%-80% are of the secreted type, with~70% sGP and~5% ssGP [7] [8] [9] [10] . During early infection, EBOV targets mainly monocytes/macrophages and dendritic cells (DCs). It is thought that these migrating cells aid in systemic dissemination of the virus throughout the host, especially into secondary lymphoid organs and the liver. Intense replication of the virus then takes place in other host cell types, including endothelial cells, epithelial cells, fibroblasts and hepatocytes [11] [12] [13] [14] . Fatal filovirus infections often involve severely dysregulated innate and adaptive immune responses, defective coagulation, and are typified by systemic cytokine storm and multi-organ failure. Immune system damage includes type-I and type-II interferon (IFN) antagonism by VP35 and VP24, respectively, NK and T-cell depletion known as bystander lymphocyte apoptosis, and impaired DC maturation [15] . Severe presentations of disease are accompanied by viral replication within and necrosis of the spleen, liver, kidneys, gonads, gastrointestinal tract and endocardium [13, 16] . In those who are fortunate enough to survive acute Ebola virus disease (EVD), the virus becomes undetectable in the blood, depicting a typical phenotype of viral clearance. However, either entire virus or viral components may remain detectable in patients relatively long after recovery, particularly in immune-privileged sites [17] [18] [19] [20] [21] [22] [23] [24] . Notably, recent studies have shown that over 1 in 4 male survivors from the 2016 outbreak contained virus within their semen up to 7-9 months past the disappearance of EVD symptoms. Furthermore, virus has still been detectable up to 16-18 months later [17] . This type of "clinical latency" or persistent infection has significance for public health in the following ways: (1) viral reservoirs within immune privileged sites have implications for reemergence and persistence of the virus within the infected individual, potentially allowing for resurgence of infection, morbidity, and mortality [25]; (2) these reservoirs may allow for the transmission of the virus to additional individuals long after initial infection, hindering efforts to control the spread of outbreaks by public health infrastructures [25]; and (3) significant political, socio-economic, and social stigma considerations must be taken into account for policies to support the normal life and travel of EVD survivors [26] [27] [28] [29] . Spread of the virus by this route is of particular concern, as several cases of sexual transmission from male to female have already been documented. One of the first such cases involved transmission from a man 6 months past his recovery to a woman in Liberia [30, 31] . To date, three additional "flare-ups" of EBOV by sexual contact have been determined, together accounting for approximately half of the eight mini-outbreaks caused by persistently infected survivors documented since 2016 [32] [33] [34] [35] . The most concerning of these cases occurred over 480 days (nearly 17 months) past the initial recovery of the patient [35] . To further complicate the matter, there have been multiple reports addressing potential asymptomatic or undiagnosed portions of the population. Previous studies have put the number of seropositive but undiagnosed/asymptomatic individuals anywhere between 0%-47% [36] [37] [38] [39] [40] [41] [42] [43] [44] . This of course implies that such individuals may represent an invisible source of viral transmission and future outbreaks. Exemplifying this is a case involving an asymptomatic mother who likely transmitted EBOV to her 9-month-old infant (as determined by sequencing and phylogenetic analysis) through breast milk, ultimately resulting in the fatality of the child [19] . Interestingly, the asymptomatic father's semen was also EBOV-positive, but was distantly related to the strains found in the mother and child. Currently, the mechanism of this viral persistence is not well characterized, although new studies have hinted as several possibilities, which will be discussed later. Extracellular vesicles (EVs) are small, membrane-bound vesicles that are released from numerous cell types and are involved in cell-to-cell communication. The intercellular communication is mediated by EV cargo, consisting of nucleic acids and proteins, which can be transferred between cells to elicit a phenotypic change in the recipient cell [45] [46] [47] . EVs are heterogeneous; as such, the current literature separates EVs into several different categories based mainly on differences in size and cellular origin, including subtypes such as exosomes and microvesicles [48] . Microvesicles bud directly from the plasma membrane and are generally larger than exosomes with diameters ranging from Viruses 2019, 11, 410 3 of 25

Ex Output:
viruses Extracellular Vesicles and Ebola Virus: A New Mechanism of Immune Evasion


Ex Input:
Basic and translational research on lung biology has discovered multiple progenitor cell types, specialized or facultative, responsible for turnover, renewal, and repair. Isolation of populations of resident lung progenitor cells (LPCs) has been described by multiple protocols, and some have been successfully applied to healthy human lung tissue. We aimed at understanding how different cell culture conditions may affect, in vitro, the phenotype of LPCs to create an ideal niche-like microenvironment. The influence of different substrates (i.e., fibronectin, gelatin, laminin) and the impact of a three-dimensional/two-dimensional (3D/2D) culture switch on the biology of LPCs isolated as lung spheroids (LSs) from normal adult human lung biopsy specimens were investigated. We applied a spheroid culture system as the selective/inductive step for progenitor cell culture, as described in many biological systems. The data showed a niche-like proepithelial microenvironment inside the LS, highly sensitive to the 3D culture system and significantly affecting the phenotype of adult LPCs more than culture substrate. LSs favor epithelial phenotypes and LPC maintenance and contain cells more responsive to specific commitment stimuli than 2D monolayer cultures, while secreting a distinctive set of paracrine factors. We have shown for the first time, to our knowledge, how culture as 3D LSs can affect LPC epithelial phenotype and produce strong paracrine signals with a distinctive secretomic profile compared with 2D monolayer conditions. These findings suggest novel approaches to maintain ex vivo LPCs for basic and translational studies. STEM CELLS TRANSLATIONAL MEDICINE 2016;5:1-11 SIGNIFICANCE A lung niche-like microenvironment was created ex vivo inside the pneumosphere. Pneumospheres have a distinctive secretomic profile compared with two-dimensional culture. Three-dimensional culture switch significantly affects lung progenitor phenotype. Lung progenitors in pneumospheres were more committed toward epithelial lineages.

Ex Output:
Tissue-Specific Progenitor and Stem Cells Human Lung Spheroids as In Vitro Niches of Lung Progenitor Cells With Distinctive Paracrine and Plasticity Properties


Ex Input:
Molecular technology has given us a greater insight into the aetiology of disease, the functioning of the immune system and the mode of action of veterinary pathogens. The knowledge gained has been used to develop new vaccines with specific, reactive antigens which elicit protective immune mediated responses (humoral and/or cell mediated) in the host. These vaccines should not burden the immune system by initiating responses against non-essential antigens. However, the efficacy of these vaccines is only as good as the delivery technology or route used to present them to the immune system. Some vaccines, traditionally given by the parenteral route, are now given by the natural route; either orally or intranasally. Two major advantages, often interrelated, are the rapid onset of immunity and stimulation of the local, mucosal immunity. These new technologies are now making an impact on current vaccine development. The balance has to be found between what is technologically feasible and what will provide at least as good a protective immunity as current, conventional vaccines. As new and emerging diseases appear globally, new opportunities arise for molecular and conventional technologies to be applied to both the development and delivery of novel vaccines, as well as the improvement of vaccines in current use. #

Ex Output:

Overview of new vaccines and technologies