LitCovid-sentences  

PMC:7019868 / 1647-6464 JSONTXT 11 Projects

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Id Subject Object Predicate Lexical cue
T11 0-2 Sentence denotes 1.
T12 3-15 Sentence denotes Introduction
T13 16-157 Sentence denotes Porcine epidemic diarrhea virus (PEDV) is an enveloped, positive-sense and single stranded RNA virus belonging to the genus Alphacoronavirus.
T14 158-367 Sentence denotes PEDV is the causative agent of porcine epidemic diarrhea (PED), a historic, highly contagious enteric swine disease characterized by diarrhea, dehydration and poor growth performance in pigs at all ages [1,2].
T15 368-564 Sentence denotes PED was first identified in 1971 in the United Kingdom, and subsequently became an endemic disease in the Europe and most Asian countries with a low mortality rate and limited economic losses [1].
T16 565-705 Sentence denotes For decades, the disease was controlled through the use of live attenuated vaccines (LAVs) derived from the PEDV prototypes, CV777- or DR13.
T17 706-839 Sentence denotes Unfortunately, in late 2010, a new highly virulent PEDV strain emerged in China and quickly spread worldwide, including Taiwan [3,4].
T18 840-1100 Sentence denotes Moreover, the conventional LAV failed to induce protection against this new virulent PEDV strain, consequently resulting in nearly 100% mortality amongst neonatal piglets and leading to substantial economic impacts on swine markets in the affected regions [5].
T19 1101-1164 Sentence denotes Phylogenetic analysis categorizes PEDV into two genogroups [2].
T20 1165-1362 Sentence denotes Genogroup I consists primarily of the historic, low-virulent PEDV strains that appeared around 1970, whereas genogroup II is composed of the highly virulent PEDV strains, which emerged after 2010s.
T21 1363-1570 Sentence denotes Both genogroups can be further divided into two subgroups each, namely G1a, G1b, G2a and G2b though a recent phylogenetic study identified a novel recombinant PEDV strain classified into a new G1c clade [6].
T22 1571-1682 Sentence denotes The complete genome of PEDV is approximately 28 kilobase pairs and consists of seven open reading frames (ORF).
T23 1683-1955 Sentence denotes Out of the seven, four ORFs are responsible for encoding structural proteins, namely the spike (S) glycoprotein as well as envelop (E), membrane (M), and nucleocapsid (N) proteins, which are crucial for viral morphogenesis and establishment of infection establishment [7].
T24 1956-2133 Sentence denotes Among all coronaviruses, S glycoprotein plays a particularly essential role in cell-virus interaction and acts as the vital determinants of viral virulence/attenuation [8,9,10].
T25 2134-2275 Sentence denotes S glycoprotein is a homotrimeric type I fusion protein, which can be cleaved into two parts—the S1 and S2 subunits—by cellular protease [11].
T26 2276-2482 Sentence denotes The S1 subunit contains the receptor binding domain (RBD) and several neutralizing epitopes that are essential for determining host and tissue tropism, and triggering protective host immunity, respectively.
T27 2483-2583 Sentence denotes Therefore, the S1 subunit has long been considered to be the primary target for vaccine development.
T28 2584-2725 Sentence denotes The S2 domain, on the other hand, mediates membrane fusion which facilitates release of viral RNA and infection to the neighboring cells [8].
T29 2726-2834 Sentence denotes LAVs have been shown to be the most effective way to elicit protective immunity against PEDV infection [12].
T30 2835-3011 Sentence denotes Therefore, to combat the emergence of PED as well as to immediately suppress any future outbreaks, studies have been carried out to develop safe and effective vaccines [13,14].
T31 3012-3267 Sentence denotes Aside from serial cell culture or animal passages, the reverse genetic system, which rescues genetically modified attenuated viruses, is now the common approach in generating LAV candidates for both human and animal viral diseases, including PEDV [15,16].
T32 3268-3441 Sentence denotes To this end, understanding the molecular biology and identification of virulent/attenuating determinant(s) are necessary for the rational design of potential LAV candidates.
T33 3442-3665 Sentence denotes Comparison of the genomic differences between the Vero cell-cultured attenuated G2b PEDV and their corresponding parental virulent strains has revealed a common pattern of mutation that particularly affects the S gene [12].
T34 3666-3971 Sentence denotes While the observation is reasonable considering the fundamental role of S protein in PEDV infection and induction of host immunity, a recent publication found that a singular S gene exchange had no influence on the virulence of the highly virulent G2b BJ2011C strain and avirulent G1a CHM2013 strain [17].
T35 3972-4208 Sentence denotes In the present study, we utilized reverse genetics to examine the role of the S gene in the attenuation process of PEDV using the highly virulent and attenuated G2b PEDV Pintung (PEDVPT) 52 strains, the PEDVPT-P5 and PEDVPT-P96 viruses.
T36 4209-4284 Sentence denotes Nonetheless, our findings were discordant with previous reported data [17].
T37 4285-4395 Sentence denotes We found that replacement of the S gene with the iPEDVPT-P5 virus enabled iPEDVPT-P96 to regain its virulence.
T38 4396-4520 Sentence denotes A reciprocal approach revealed that iPEDVPT-P5 virus became partly attenuated after the S gene was exchanged to iPEDVPT-P96.
T39 4521-4641 Sentence denotes Collectively, we concluded that the S gene is of critical importance to the attenuation process of the PEDVPT 52 strain.
T40 4642-4732 Sentence denotes However, mutation in the S gene alone could not completely attenuate the iPEDVPT-P5 virus.
T41 4733-4817 Sentence denotes Thus, gene(s) other than S gene could also play a role in determining the virulence.