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LitCovid-PD-FMA-UBERON

LitCovid-PD-UBERON

{"project":"LitCovid-PD-UBERON","denotations":[{"id":"T1","span":{"begin":7672,"end":7685},"obj":"Body_part"}],"attributes":[{"id":"A1","pred":"uberon_id","subj":"T1","obj":"http://purl.obolibrary.org/obo/UBERON_0002405"}],"text":"1. Introduction\nPorcine epidemic diarrhea virus (PEDV) is the etiological agent of porcine epidemic diarrhea (PED) that causes an acute and highly contagious enteric disease of swine characterized by vomiting, diarrhea, dehydration, and anorexia in pigs of all ages, especially resulting in severe diarrhea and high mortality rate in piglets. In serious cases, outbreak of PED even leads to a mortality rate of 100% in pigs [1,2,3]. The causative agent of PED was first described in the 1970s in England [4]. In 1976, an unrecognized enteric disease was reported in several European countries [5]. The viral diarrhea was collectively designated “PED” in 1982 [6]. Endemic PED had been described in both developed and developing countries, but with a low impact on the swine industry until 2010. In 2010, outbreaks of PED caused by highly pathogenic variant PEDV strains occurred in China, and this was immediately reported in other Asian counties, causing up to 100% mortality in suckling piglets [1,7,8,9]. In April 2013, PEDV entered the United States (US) for the first time and the virulent strains spread rapidly across the US [10]. Apart from almost 100% mortality rate in suckling piglets, PEDV infection also damaged the growth performance of finishing pigs [11]. The highly pathogenic strains of PEDV spread worldwide, resulting in serious problems to the swine industry and substantial economic losses [7,10,12,13]. Vaccination used to be the main strategy to prevent and control the rate of PEDV infection [14], however, the current available PEDV vaccines cannot provide complete protection for the pigs affected by the highly pathogenic strains. The optimal vaccines should induce efficient maternal antibodies in sows that could be transmitted to the offspring and protect neonatal suckling piglets from PEDV. The vaccination method is critically associated with the antibodies’ induction by PEDV vaccines. Oral vaccination with attenuated PEDV seems to be more efficacious than injectable vaccine. Oral immunization of PEDV-seronegative pregnant sows with attenuated PEDV leads to lower mortality rate of piglets and higher amounts of IgA transferred from the sows to the offspring than that in the intramuscularly injected group. However, the duration of virus shedding after challenge was not reduced compared to the control group [15]. The immunization dose of the virus for sows and the challenge dose of the virus for piglets significantly affected the protection against virus challenge [16]. Moreover, epidemiological studies have demonstrated that the prevalent strains causing previous PED outbreaks in China in 2010 and the recent outbreaks in North America and Asia all belong to the genogroup II (GII) PEDV and the S gene of GIIb PEDV contains typical insertion and deletion mutations [2]. Therefore, new PEDV vaccines should be developed based on these variant strains. The biological characteristics, pathogenicity and immune protective effects of GIIb PEDV strains should be studied as soon as possible. An inactivated vaccine based on genotype IIb strain AJ1102 developed by Wuhan Keqian company was approved for clinical trial in 2014. In addition, the lactic acid bacteria (LAB) that have the ability to interact with the intestinal cells can be used as a potential vector for improving delivery of oral vaccines [17]. Developing the transgenic plants expressing antigenic proteins as edible vaccines to induce efficient mucosal immune responses might be a prominent strategy to prevent PEDV infection [18]. Choosing appropriate and effective adjuvants for PEDV vaccines to enhance adaptive immune response is also important. In addition, the construction of recombinant PEDV with deletion or mutation of the immune antagonistic regions or sites is a potential strategy to develop PEDV vaccines as well. The produced modified antigens will induce an increased and earlier immune response in pigs, compared with the antigens from wildtype viruses. Therefore, the modification of viral antigens, the optimization of immunization methods, screening effective adjuvants, and exploiting a new generation of vaccines are promising directions for the control of PED.PEDV is classified as a coronavirus (CoV), due to its similar electron microscopic appearance and polypeptide structure to other CoVs [19,20,21]. CoVs (subfamily Coronavirinae, family Coronaviridae, order Nidovirales) are a large family of viruses that have broad host ranges and have caused global public health issues [22]. The currently known CoVs are divided into four genera, which include Alphacoronavirus (α-CoV), Betacoronavirus (β-CoV), Gammacoronavirus (γ-CoV) and Deltacoronavirus (δ-CoV), according to the genome phylogeny and serotypes. CoVs give rise to a wide spectrum of diseases in humans and animals, but generally fall into two classes, with respiratory or enteric tropisms. Moreover, the β-CoV genus consists of a lot of important CoVs that result in serious respiratory illnesses in humans, such as severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and the latest 2019 novel coronavirus (SARS-CoV2). SARS-CoV resulted in an outbreak of severe respiratory disease through China in 2002–2003 [23,24]. MERS-CoV was first identified in Saudi Arabia in 2012 and is associated with severe pneumonia and acute respiratory distress syndrome (ARDS) that results in a high mortality (~35%) [25,26]. SARS-CoV2 was identified in Wuhan, China in December 2019, which leads to similar symptoms in humans as SARS-CoV, but it is more infectious to humans than SARS-CoV [27,28]. Furthermore, α-CoV genus includes porcine respiratory coronavirus (PRCV) and various enteric CoVs that lead to viral diarrhea in pigs, such as PEDV, transmissible gastroenteritis virus (TGEV), and HKU2-like porcine enteric alphacoronavirus (PEAV) [29,30]. PRCV infects the upper respiratory epithelial cells and alveolar macrophages, but the clinical manifestations caused by PRCV are not significant [31]. The swine enteric CoVs cause severe diarrhea, vomiting, and mortality in piglets, having contributed to enormous economic losses to the global swine industry [6].\nPEDV is the main causative pathogen of viral diarrhea in piglets. Over the years, significant work has been done to investigate PEDV pathogenesis and prevention. Aminopeptidase N protein (APN, also known as CD13) is identified as a functional receptor of PEDV and TGEV [32,33,34]. APN, a 150 KD type II transmembrane glycoprotein, is mainly expressed on the apical membrane of mature enterocytes [35]. APN binds to the 477-629 amino-acid region in the C-terminal region of PEDV spike 1 (S1) protein [34]. Apart from APN, PEDV is able to bind to sialic acids [36]. It remains unknown whether PEDV uses sugar coreceptors during viral infection [34,36]. PEDV infects multiple cell lines from different species including bat and primate (human and non-human) in vitro. The ability of PEDV to infect the cells of different species indicates that the virus utilizes the evolutionarily conserved cell components as receptors, thereby enhancing the potential for cross-species and potentially, zoonotic transmission [37,38]. The highly pathogenic variant strains of PEDV were identified in 2010 and caused a high morbidity of up to 100% in piglets, and since then, these strains become dominant, leading to most of the acute outbreaks of PED worldwide [1,7,8]. The high virulence of these strains is critically associated with the immune evasion mechanisms employed by the virus. PEDV has evolved different strategies to delicately manipulate and damage the host innate immune system for their multiplication. Clarification of these mechanisms is critical for understanding the host range, tropisms, pathogenesis, and for developing effective vaccines and antiviral drugs to curb the spread of PEDV in pigs. In this review, we provide an overview of different mechanisms used by PEDV to evade host innate immune responses."}

LitCovid-PD-MONDO

LitCovid-PD-CLO

LitCovid-PD-CHEBI

LitCovid-PD-HP

LitCovid-PD-GO-BP

{"project":"LitCovid-PD-GO-BP","denotations":[{"id":"T11","span":{"begin":1229,"end":1235},"obj":"http://purl.obolibrary.org/obo/GO_0040007"},{"id":"T12","span":{"begin":3454,"end":3478},"obj":"http://purl.obolibrary.org/obo/GO_0002385"},{"id":"T13","span":{"begin":3615,"end":3639},"obj":"http://purl.obolibrary.org/obo/GO_0002250"},{"id":"T14","span":{"begin":3624,"end":3639},"obj":"http://purl.obolibrary.org/obo/GO_0006955"},{"id":"T15","span":{"begin":3905,"end":3920},"obj":"http://purl.obolibrary.org/obo/GO_0006955"},{"id":"T16","span":{"begin":6343,"end":6355},"obj":"http://purl.obolibrary.org/obo/GO_0009405"},{"id":"T17","span":{"begin":6836,"end":6851},"obj":"http://purl.obolibrary.org/obo/GO_0016032"},{"id":"T18","span":{"begin":7472,"end":7481},"obj":"http://purl.obolibrary.org/obo/GO_0016032"},{"id":"T19","span":{"begin":7472,"end":7481},"obj":"http://purl.obolibrary.org/obo/GO_0009405"},{"id":"T20","span":{"begin":7533,"end":7547},"obj":"http://purl.obolibrary.org/obo/GO_0042783"},{"id":"T21","span":{"begin":7665,"end":7678},"obj":"http://purl.obolibrary.org/obo/GO_0045087"},{"id":"T22","span":{"begin":7802,"end":7814},"obj":"http://purl.obolibrary.org/obo/GO_0009405"},{"id":"T23","span":{"begin":8000,"end":8023},"obj":"http://purl.obolibrary.org/obo/GO_0045087"}],"text":"1. Introduction\nPorcine epidemic diarrhea virus (PEDV) is the etiological agent of porcine epidemic diarrhea (PED) that causes an acute and highly contagious enteric disease of swine characterized by vomiting, diarrhea, dehydration, and anorexia in pigs of all ages, especially resulting in severe diarrhea and high mortality rate in piglets. In serious cases, outbreak of PED even leads to a mortality rate of 100% in pigs [1,2,3]. The causative agent of PED was first described in the 1970s in England [4]. In 1976, an unrecognized enteric disease was reported in several European countries [5]. The viral diarrhea was collectively designated “PED” in 1982 [6]. Endemic PED had been described in both developed and developing countries, but with a low impact on the swine industry until 2010. In 2010, outbreaks of PED caused by highly pathogenic variant PEDV strains occurred in China, and this was immediately reported in other Asian counties, causing up to 100% mortality in suckling piglets [1,7,8,9]. In April 2013, PEDV entered the United States (US) for the first time and the virulent strains spread rapidly across the US [10]. Apart from almost 100% mortality rate in suckling piglets, PEDV infection also damaged the growth performance of finishing pigs [11]. The highly pathogenic strains of PEDV spread worldwide, resulting in serious problems to the swine industry and substantial economic losses [7,10,12,13]. Vaccination used to be the main strategy to prevent and control the rate of PEDV infection [14], however, the current available PEDV vaccines cannot provide complete protection for the pigs affected by the highly pathogenic strains. The optimal vaccines should induce efficient maternal antibodies in sows that could be transmitted to the offspring and protect neonatal suckling piglets from PEDV. The vaccination method is critically associated with the antibodies’ induction by PEDV vaccines. Oral vaccination with attenuated PEDV seems to be more efficacious than injectable vaccine. Oral immunization of PEDV-seronegative pregnant sows with attenuated PEDV leads to lower mortality rate of piglets and higher amounts of IgA transferred from the sows to the offspring than that in the intramuscularly injected group. However, the duration of virus shedding after challenge was not reduced compared to the control group [15]. The immunization dose of the virus for sows and the challenge dose of the virus for piglets significantly affected the protection against virus challenge [16]. Moreover, epidemiological studies have demonstrated that the prevalent strains causing previous PED outbreaks in China in 2010 and the recent outbreaks in North America and Asia all belong to the genogroup II (GII) PEDV and the S gene of GIIb PEDV contains typical insertion and deletion mutations [2]. Therefore, new PEDV vaccines should be developed based on these variant strains. The biological characteristics, pathogenicity and immune protective effects of GIIb PEDV strains should be studied as soon as possible. An inactivated vaccine based on genotype IIb strain AJ1102 developed by Wuhan Keqian company was approved for clinical trial in 2014. In addition, the lactic acid bacteria (LAB) that have the ability to interact with the intestinal cells can be used as a potential vector for improving delivery of oral vaccines [17]. Developing the transgenic plants expressing antigenic proteins as edible vaccines to induce efficient mucosal immune responses might be a prominent strategy to prevent PEDV infection [18]. Choosing appropriate and effective adjuvants for PEDV vaccines to enhance adaptive immune response is also important. In addition, the construction of recombinant PEDV with deletion or mutation of the immune antagonistic regions or sites is a potential strategy to develop PEDV vaccines as well. The produced modified antigens will induce an increased and earlier immune response in pigs, compared with the antigens from wildtype viruses. Therefore, the modification of viral antigens, the optimization of immunization methods, screening effective adjuvants, and exploiting a new generation of vaccines are promising directions for the control of PED.PEDV is classified as a coronavirus (CoV), due to its similar electron microscopic appearance and polypeptide structure to other CoVs [19,20,21]. CoVs (subfamily Coronavirinae, family Coronaviridae, order Nidovirales) are a large family of viruses that have broad host ranges and have caused global public health issues [22]. The currently known CoVs are divided into four genera, which include Alphacoronavirus (α-CoV), Betacoronavirus (β-CoV), Gammacoronavirus (γ-CoV) and Deltacoronavirus (δ-CoV), according to the genome phylogeny and serotypes. CoVs give rise to a wide spectrum of diseases in humans and animals, but generally fall into two classes, with respiratory or enteric tropisms. Moreover, the β-CoV genus consists of a lot of important CoVs that result in serious respiratory illnesses in humans, such as severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and the latest 2019 novel coronavirus (SARS-CoV2). SARS-CoV resulted in an outbreak of severe respiratory disease through China in 2002–2003 [23,24]. MERS-CoV was first identified in Saudi Arabia in 2012 and is associated with severe pneumonia and acute respiratory distress syndrome (ARDS) that results in a high mortality (~35%) [25,26]. SARS-CoV2 was identified in Wuhan, China in December 2019, which leads to similar symptoms in humans as SARS-CoV, but it is more infectious to humans than SARS-CoV [27,28]. Furthermore, α-CoV genus includes porcine respiratory coronavirus (PRCV) and various enteric CoVs that lead to viral diarrhea in pigs, such as PEDV, transmissible gastroenteritis virus (TGEV), and HKU2-like porcine enteric alphacoronavirus (PEAV) [29,30]. PRCV infects the upper respiratory epithelial cells and alveolar macrophages, but the clinical manifestations caused by PRCV are not significant [31]. The swine enteric CoVs cause severe diarrhea, vomiting, and mortality in piglets, having contributed to enormous economic losses to the global swine industry [6].\nPEDV is the main causative pathogen of viral diarrhea in piglets. Over the years, significant work has been done to investigate PEDV pathogenesis and prevention. Aminopeptidase N protein (APN, also known as CD13) is identified as a functional receptor of PEDV and TGEV [32,33,34]. APN, a 150 KD type II transmembrane glycoprotein, is mainly expressed on the apical membrane of mature enterocytes [35]. APN binds to the 477-629 amino-acid region in the C-terminal region of PEDV spike 1 (S1) protein [34]. Apart from APN, PEDV is able to bind to sialic acids [36]. It remains unknown whether PEDV uses sugar coreceptors during viral infection [34,36]. PEDV infects multiple cell lines from different species including bat and primate (human and non-human) in vitro. The ability of PEDV to infect the cells of different species indicates that the virus utilizes the evolutionarily conserved cell components as receptors, thereby enhancing the potential for cross-species and potentially, zoonotic transmission [37,38]. The highly pathogenic variant strains of PEDV were identified in 2010 and caused a high morbidity of up to 100% in piglets, and since then, these strains become dominant, leading to most of the acute outbreaks of PED worldwide [1,7,8]. The high virulence of these strains is critically associated with the immune evasion mechanisms employed by the virus. PEDV has evolved different strategies to delicately manipulate and damage the host innate immune system for their multiplication. Clarification of these mechanisms is critical for understanding the host range, tropisms, pathogenesis, and for developing effective vaccines and antiviral drugs to curb the spread of PEDV in pigs. In this review, we provide an overview of different mechanisms used by PEDV to evade host innate immune responses."}

LitCovid-sentences

2_test

LitCovid-PubTator

PMC:7281546 / 1190-9214 JSONTXT

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PMC:7281546 / 1190-9214 JSON TXT