Enterovirus 70 Receptor Utilization Is Controlled by Capsid Residues That Also Regulate Host Range and Cytopathogenicity

Abstract

Three of these capsid amino acids are predicted to be located in the canyon encircling the fivefold axis of symmetry, one amino acid is found at the fivefold axis of symmetry, and one is located the interior of the capsid. The five EV70 residues define a region of the capsid that controls viral host range, DAF utilization, and cytopathogenicity.Acute hemorrhagic conjunctivitis (AHC) is a viral infection of the eye that was first reported in Ghana in 1969 (5). This highly contagious infection is transmitted through direct or indirect contact with eye secretions. An incubation period of 24 to 48 h is followed by rapid onset of ocular pain, swelling of the eyelids, excessive tearing, pain, and subconjunctival hemorrhage. The disease usually resolves in 3 to 7 days. Enterovirus type 70 (EV70), a member of the Picornaviridae, is one of the etiologic agents of AHC. This recently emerged virus (25) has caused two global AHC pandemics (4, 24), underscoring its highly transmissible nature.EV70 is an unusual enterovirus because AHC is not initiated through the alimentary tract but upon introduction of the virus directly into the eye. The pathogenesis of AHC has not been studied due to lack of a suitable animal model. EV70 has been shown to cause conjunctivitis in the rabbit (21), but little progress has been made with this animal model because there are few immunological reagents or defined mutants available. In humans, paralysis occurs in approximately 1 of 10,000 symptomatic EV70 infections (41). Unlike poliomyelitis, this complication is transient and involves both acute flaccid paralysis of the lower limbs and cranial nerve palsies. The mechanism by which EV70 enters the central nervous system (CNS) and the associated switch from eye to CNS pathogenesis has not been studied.Several mouse models for viral diseases have been established by producing transgenic mice expressing cell receptors for viruses. These animal models have proven valuable for studying the pathogenesis of poliomyelitis (15, 34), measles (3,9,16,28,33), and echovirus paralysis and myocarditis (17). At least one cell receptor for EV70 is decay accelerating factor (DAF), also known as CD55 (19). CD55 is a member of the family of regulators of complement activation and is an important modulator of the complement system (23). Treatment of cells with neuraminidase blocks binding of EV70 (1, 18, 39); however, this effect is not due to removal of sialic acid on CD55. Rather, a second sialylated cell surface protein may be required for EV70 binding. The finding that EV70 can infect human leukocyte cell lines that do not produce CD55 at detectable levels also suggests the presence of a second cell surface receptor for the virus (10).To facilitate genetic analysis of EV70 receptor utilization, the first infectious DNA copy of the EV70 genome was constructed and used to study two strains of the virus with a distinct host range. One virus isolate, EV70-Rmk, replicates in rhesus monkey kidney cells and poorly in HeLa cells and does not cause cytopathic effects. H...

Enterovirus strain and type-specific differences in growth kinetics and virus-induced cell destruction in human pancreatic duct epithelial HPDE cells

“…The identification of a single CV-B6 amino acid that is most likely responsible for the lytic phenotype, more efficient progeny production and DAF-usage is in line with previous reports that have shown strong effects for single or few amino acid substitutions on the receptor usage, cell and tissue tropism and pathogenesis (Al-Hello et al, 2005Caggana et al, 1993;Chua et al, 2008;Cifuente et al, 2011;Gullberg et al, 2010;Halim and Ramsingh, 2000;Kim and Racaniello, 2007;Knowlton et al, 1996;Novoselov et al, 2012;Paananen et al, 2013;Pan et al, 2011;Pelletier et al, 1998;Polacek et al, 2005;Ramsingh and Collins, 1995;Ramsingh et al, 1997;Schmidtke et al, 2000). A phenomenon similar to our CV-B6 model has been described previously using CV-B2-Ohio strain that induces persistent non-cytolytic infection in CAR-deficient RD-cells.…”

Proteinase 2AproIs Essential for Enterovirus Replication in Type I Interferon-Treated Cells

“…VSV was obtained from the American Type Culture Collection (Manassas, VA) and propagated in HeLa cells. EV70 was produced from an infectious clone (34) and propagated in HeLa cells. Virus titers were determined by plaque assay on HeLa cells.…”

The Crystal Structure of a Coxsackievirus B3-RD Variant and a Refined 9-Angstrom Cryo-Electron Microscopy Reconstruction of the Virus Complexed with Decay-Accelerating Factor (DAF) Provide a New Footprint of DAF on the Virus Surface

“…For many picornaviruses, a receptor binds into the canyon and dislodges this "pocket factor," initiating conformational changes that lead to the formation of "A particles" and the subsequent uncoating of the virion (1, 12, 33, 39, 66). The major CVB receptor, the coxsackievirus-adenovirus receptor (CAR), binds within the CVB3 canyon (37) and causes the formation of A particles (16,35).A number of CVB isolates bind a second receptor, decayaccelerating factor (DAF) (CD55), a molecule that also serves as a receptor for many other enteroviruses (2,3,18,23,24,43,45). DAF, which is expressed on virtually all cell surfaces, acts to protect cells from lysis by complement (34), by binding and degrading C3/C5 convertases, the central amplification enzymes of the complement cascade (5,27,28,34).…”

“…A number of CVB isolates bind a second receptor, decayaccelerating factor (DAF) (CD55), a molecule that also serves as a receptor for many other enteroviruses (2,3,18,23,24,43,45). DAF, which is expressed on virtually all cell surfaces, acts to protect cells from lysis by complement (34), by binding and degrading C3/C5 convertases, the central amplification enzymes of the complement cascade (5,27,28,34).…”