Isolation and identification of a novel human parechovirus

Abstract

A cytopathic agent (A308/99) was isolated using Vero cells from a stool specimen of a 1-year-old patient with transient paralysis. The agent was approximately 28 nm in diameter with a distinct ultrastructure resembling the virus particle of an enterovirus. It could not be neutralized by antisera against human picornaviruses such as human enterovirus, Aichi virus or human parechovirus. The virion contained three capsid proteins with molecular masses of 38, 30?3 and 30 kDa. Determination of the complete nucleotide sequence of A308/99 revealed that the nucleotide and deduced amino acid sequences were closely related to those of human parechoviruses. When 11 regions encoding the structural and non-structural proteins were compared, A308/99 had between 75 and 97 % and 73 and 97 % nucleotide identity with human parechovirus type 1 (HPeV-1) and type 2 (HPeV-2), respectively. The most distinctive divergence was seen in VP1, which had 74?5 % and 73?1 % nucleotide identity with HPeV-1 and HPeV-2, respectively. Viruses related to A308/99 were also isolated from three patients with gastroenteritis, exanthema or respiratory illnesses. A308/99 and these other three isolates had no arginine-glycine-aspartic acid (RGD) motif, which is located near the C terminus of VP1 in HPeV-1 and HPeV-2. A seroepidemiological study revealed that the prevalence of A308/99 antibodies was low (15 %) among infants but became higher with age, reaching more than 80 % by 30 years of age. These observations indicate that A308/99 is genetically close to, but serologically and genetically distinct from, HPeV-1 and HPeV-2 and accordingly can be classified as third serotype of human parechovirus.

Recombinant VP1 protein of duck hepatitis virus 1 expressed in Pichia pastoris and its immunogenicity in ducks

“…In addition, we identified a novel feature in the VP1 of the VJ09 isolate: that it lacks an RGD motif. The RGD motif is a consensus sequence in picornaviruses that mediates many cell-cell and microbe-host interactions (Joki-Korpela et al, 2000;Boonyakiat et al, 2001;Ito et al, 2004). The RGD motif is involved in viral attachment through binding to the cellular integrin receptors.…”

Human Parechovirus Infections in Monkeys with Diarrhea, China

“…The polyprotein encoded capsid proteins VP0 (312 aa), VP3 (229 aa), and VP1 (234 aa) and nonstructural proteins 2A (150 aa), 2B (122 aa), 2C (329 aa), 3A (117 aa), 3B (20 aa), 3C (200 aa), and 3D (469 aa). The integrin binding motif arginine–glycine–aspartic acid was identified close to the C terminus of VP1 ( 8 , 14 ). …”

Human picornaviruses associated with neurological diseases and their neutralization by antibodies

“…A study of sera from different populations in Finland and the Netherlands only revealed neutralizing responses to HPeV-3 in about 10 % of the samples and very low titres of neutralizing antibodies post-infection [175]. By contrast, researchers in Japan detected neutralizing responses to HPeV-3 in 67 % of individuals between 7 months and 40 years old [94], and reported high titres of neutralizing antibodies after 3 months post-infection in all studied individuals [176]. The virus strains used in the European and Japanese studies were different, suggesting that there is antigenic variation in HPeV-3.…”

“…HPeV-3 was first isolated in 1999 from an infant with severe CNS disease [94], and since then different studies have recognized it as the most or second most prevalent virus causing CNS infections in infants under three months old [7,[95][96][97][98]. Outbreaks of HPeV-3 usually occur in the summer/autumn seasons and have a distinct biennial pattern [96,98].…”