Susceptibility of mouse primary cortical neuronal cells to coxsackievirus B

Many steps of viral replication are dependent on the interaction of viral proteins with host cell components. To identify rhinovirus proteins involved in such interactions, human rhinovirus 39 (HRV39), a virus unable to replicate in mouse cells, was adapted to efficient growth in mouse cells producing the viral receptor ICAM-1 (ICAM-L cells). Amino acid changes were identified in the 2B and 3A proteins of the adapted virus, RV39/L. Changes in 2B were sufficient to permit viral growth in mouse cells; however, changes in both 2B and 3A were required for maximal viral RNA synthesis in mouse cells. Examination of infected HeLa cells by electron microscopy demonstrated that human rhinoviruses induced the formation of cytoplasmic membranous vesicles, similar to those observed in cells infected with other picornaviruses. Vesicles were also observed in the cytoplasm of HRV39-infected mouse cells despite the absence of viral RNA replication. Synthesis of picornaviral nonstructural proteins 2C, 2BC, and 3A is known to be required for formation of membranous vesicles. We suggest that productive HRV39 infection is blocked in ICAM-L cells at a step posttranslation and prior to the formation of a functional replication complex. The observation that changes in HRV39 2B and 3A proteins lead to viral growth in mouse cells suggests that one or both of these proteins interact with host cell proteins to promote viral replication.Picornaviruses are small RNA viruses with a single-stranded, positive-sense genome of approximately 7 to 8 kb enclosed in a nonenveloped, icosahedral capsid. These viruses are responsible for a wide range of diseases including foot-and-mouth disease, hepatitis, poliomyelitis, and the common cold. Following cell entry, the viral genome is translated as a single polyprotein that is co-and posttranslationally cleaved by viral proteases, yielding both precursor proteins and end products. Many of the precursor proteins are essential for virus replication, with functions distinct from the end products (29,40,42). Four structural proteins produced from the P1 region of the genome form the viral capsid. Nonstructural proteins of the P2 and P3 region of the genome encode all of the viral proteins responsible for genomic RNA replication.Viral genome replication occurs on the surface of cytoplasmic vesicles induced by the synthesis of viral proteins 2C and 3A and the precursor 2BC (70). These vesicles are formed in conjunction with massive cell membrane proliferation (4, 7) and increased cellular synthesis of phospholipids (32). With the exception of the two viral proteases 2A pro and 3C pro , all of the nonstructural proteins have been found on the surface of these vesicles and are thought to interact in the replication complex (26,59,61,70). The vesicles assemble into a rosette, and the replication complex forms on the inner face of the rosette (13, 26). Salt-induced dissociation of the rosette demonstrated that the individual vesicles themselves can also support replication initiation and elongation (26). Neither t...

Section: Discussionmentioning

confidence: 99%

Amino Acid Changes in Proteins 2B and 3A Mediate Rhinovirus Type 39 Growth in Mouse Cells

Harris

Racaniello

2005

“…1A) (23). Previous studies by our group and others have implied that CVB3 infection causes productive virus replication, which results in cell death in both permissive and target cells (1,2,9), a process closely associated with CVB3-related human illness (6,27,28). Thus, directly blocking viral replication may be an effective strategy for treating the clinical symptoms of CVB3 infection.…”

mentioning

confidence: 99%

A Small Interfering RNA Targeting Coxsackievirus B3 Protects Permissive HeLa Cells from Viral Challenge

Ahn¹,

Jun

Lee³

et al. 2005

Self Cite

We examined the ability of small interfering RNAs (siRNAs) to disrupt infection by coxsackievirus B3 (CVB3). The incorporation of siRNAs dramatically decreased cell death in permissive HeLa cells in parallel with a reduction in viral replication. Three of four siRNAs had potent anti-CVB3 activity. The present study thus demonstrates that the antiviral effect is due to the downregulation of viral replication. In addition, an effective CVB3-specific siRNA had similar antiviral effects in other related enteroviruses possessing sequence homology in the targeted region. Because the CVB3-specific siRNA is effective against other enteroviruses, siRNAs have potential for a universal antienterovirus strategy.

“…If human neurotropic viruses persist, they could provide a chronic inflammatory stimulus, leading to regional cytokine induction and activation of autoreactive T cells through molecular mimicry and bystander activation (32,45). This may be especially true for viruses, such as coxsackievirus, which have the ability to infect stem cells (24) and neurons (1). Recently, we have shown that coxsackievirus B3 (CVB3) targets proliferating cells in regions of the neonatal CNS supporting neurogenesis (24).…”

mentioning

confidence: 99%

Viral Persistence and Chronic Immunopathology in the Adult Central Nervous System following Coxsackievirus Infection during the Neonatal Period

Feuer

Ruller

et al. 2009

Coxsackieviruses are significant human pathogens, and the neonatal central nervous system (CNS) is a major target for infection. Despite the extreme susceptibility of newborn infants to coxsackievirus infection and viral tropism for the CNS, few studies have been aimed at determining the long-term consequences of infection on the developing CNS. We previously described a neonatal mouse model of coxsackievirus B3 (CVB3) infection and determined that proliferating stem cells in the CNS were preferentially targeted. Here, we describe later stages of infection, the ensuing inflammatory response, and subsequent lesions which remain in the adult CNS of surviving animals. High levels of type I interferons and chemokines (in particular MCP-5, IP10, and RANTES) were upregulated following infection and remained at high levels up to day 10 postinfection (p.i). Chronic inflammation and lesions were observed in the hippocampus and cortex of surviving mice for up to 9 months p.i. CVB3 RNA was detected in the CNS up to 3 months p.i at high abundance (ϳ10 6 genomes/mouse brain), and viral genomic material remained detectable in culture after two rounds of in vitro passage. These data suggest that CVB3 may persist in the CNS as a low-level, noncytolytic infection, causing ongoing inflammatory lesions. Thus, the effects of a relatively common infection during the neonatal period may be long lasting, and the prognosis for newborn infants recovering from acute infection should be reexplored.