Advances in Crosstalk between Porcine Circoviruses and Host

Abstract

Porcine circoviruses (PCVs), including PCV1 to PCV4, are non-enveloped DNA viruses with a diameter of about 20 nm, belonging to the genus Circovirus in the family Circoviridae. PCV2 is an important causative agent of porcine circovirus disease or porcine circovirus-associated disease (PCVD/PCVAD), which is highly prevalent in pigs and seriously affects the swine industry globally. Furthermore, PCV2 mainly causes subclinical symptoms and immunosuppression, and PCV3 and PCV4 were detected in healthy pigs, sick pigs, and other animals. Although the pathogenicity of PCV3 and PCV4 in the field is still controversial, the infection rates of PCV3 and PCV4 in pigs are increasing. Moreover, PCV3 and PCV4 rescued from infected clones were pathogenic in vivo. It is worth noting that the interaction between virus and host is crucial to the infection and pathogenicity of the virus. This review discusses the latest research progress on the molecular mechanism of PCVs–host interaction, which may provide a scientific basis for disease prevention and control.

Circular Single-Stranded DNA: Discovery, Biological Effects, and Applications

“…The crosstalk between PCVs and hosts has been extensively discussed and the role of CssDNAs has been summarized by Niu et al 52 A hairpin-forming sequence motif, also known as oligodeoxyribonucleotides, has been reported in the PCV2 DNA genome. 243 They have been confirmed to have the ability of IFN-α inhibitory activity and have also been found to suppress the mRNA expression for IL-6, IL-10, and IL-12p40.…”

“…Porcine circovirus (PCV), belonging to the family Circoviridae in the genus Circovirus , imposes significant economic losses on the global pig farming industry . PCV is a small, icosahedral, nonenveloped, circular single-stranded DNA virus with a diameter ranging from 13 and 25 nm , and is responsible for porcine circovirus virus-associated diseases (PCVAD), such as porcine dermatitis and nephropathy syndrome, postweaning multisystemic wasting syndrome (PMWS), reproductive failure, acute pulmonary edema, porcine respiratory disease complex and granulomatous enteritis. − There are currently four recognized types: PCV1 to PCV4 (Figure C), with PCV1 generally considered nonpathogenic . In contrast, PCV2 is an important causative agent of PCVAD.…”

Phylogenetic and Structural Analysis of Porcine Circovirus Type 2 from 2016 to 2021 in Jilin Province, China

“…Porcine circovirus disease (PCVD) is an infectious disease of pigs caused by porcine circoviruses (PCVs), which occur in pig farms worldwide [1,2]. PCVs are single-strand circular DNA viruses belonging to the Circovirus genus Circoviridae family, which contains four genotypes, namely PCV1, PCV2, PCV3, and PCV4 [1][2][3]. Among the PCVs, PCV2 is the most widely distributed and has caused severe disease and economic losses worldwide.…”

“…The genome of PCV2 contains 11 open reading frames (ORFs), of which the Rep and Cap proteins, encoded by the ORF1 and ORF2, are the main proteins [21]. Rep is a replicase, and Cap is the only structural protein that contains the majority of the antigenic epitopes and is responsible for immune stimulation [1,22]. This study analyzed the clinical samples collected in the Jilin Province of China from 2016 to 2021, followed by the genotyping and genetic diversity analysis of the PCV2 isolates.…”

Flavonoids as Potential Antiviral Agents for Porcine Viruses

“…Swine viruses, such as transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), Influenza A virus (IAV), African swine fever virus (ASFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus (PCV), and pseudorabies virus (PRV), cause severe diseases through single infection and/or coinfection [1][2][3][4][5]. Furthermore, viruses, such as PCV and PRRSV, are usually the primary pathogens that break through the host's defense, which generally leads to immunosuppression and causes secondary infection of other pig pathogens [6][7][8]. Therefore, prevention and treatment of virus diseases are regarded as the primary task of the pig industry.…”