Biomedical subjects

Nélida A Candurra

Publications and source records attributed to Nélida A Candurra.

3 recordsLinked to original sources

PubMed2005

Polarized entry and release of Junin virus, a New World arenavirus.

Junin virus (JUNV), the causative agent of Argentine haemorrhagic fever, is a human pathogen that naturally enters the body through the epithelial cells of the respiratory and digestive tracts. The interaction of JUNV with two types of polarized epithelial cultures, Vero C1008 and A549, was investigated. Radioactive virus-binding assays showed that JUNV infects polarized lines preferentially through the apical surface. High-level expression of viral nucleoprotein was detected in polarized cell lines infected through the apical domain. Virus production from apical media was about 100-fold higher than that found into the basolateral medium. Confocal-immunofluorescence analysis revealed high-level expression of glycoprotein at the apical-membrane surface. Disruption of the microtubule network by colchicine impaired JUNV vectorial release. This is the first study to analyse the interaction between a member of the virus family Arenaviridae and polarized epithelial cells, showing preferential entry and release from the apical plasma membrane.

Animals↗

PubMed2003

Intermediate filament integrity is required for Junin virus replication.

The role of the cytoskeletal framework in Junin virus (JUNV) replication has already been demonstrated with compounds interfering with the microfilament (MF) and microtubule (MT) networks. In this work, we evaluated the role of intermediate filaments (IF) during JUNV infection. We tested the effect of acrylamide, a compound that selectively disrupts IF, in culture of three different cell types: Vero cells, murine astrocytes and human foreskin fibroblasts. Perturbation of intermediate filaments had an inhibitory effect on JUNV production within a range of acrylamide concentration of 0.5-3mM in a dose-dependent manner, without cell viability modification. Recovery experiments showed that viral production was partially increased when medium containing acrylamide was replaced by normal maintenance medium (MM). The adsorption and internalization steps were not affected by IF disruption. The expression of JUNV proteins was highly reduced in the presence of 2mM acrylamide while immunofluorescence staining of IF showed network disruption with the formation of cytoplasmic aggregates containing vimentin or glial fibrillary acidic protein (GFAP). We conclude that the IF network may play a role in the early step of JUNV multiplication, subsequent to virus entry and that its integrity is a necessary condition for the normal replication of JUNV in neural and fibroblast cells as well as in the Vero cell line.

Acrylamide↗

PubMed2003

Differential inhibitory action of two azoic compounds against arenaviruses.

The action of five azo-based compounds against the arenaviruses Junin (JUNV) and Tacaribe (TCRV) was evaluated in vitro by a virus yield inhibition assay in Vero cells and a cell-free virion inactivation assay. The compound 2-azo-(1'-(2'-nitroso)naphthyl)-benzoate (ANNB) was the most effective inhibitor of arenavirus production in Vero cells with EC(50) (effective concentration 50%) values in the range 6.5-26.2 microM and without inactivating properties. By contrast, the azodicarbonamide (ADA) was very effective in inactivating both arenaviruses with IC(50) (inactivating concentration 50%) values of 7.6 and 5.3 microM against JUNV and TCRV, respectively. The virucidal activity of ADA was time- and temperature-dependent. ANNB had no inhibitory action on virus binding or penetration of target cells and did not affect the synthesis of viral proteins. The most likely event susceptible to ANNB would be the process of intracellular virion assembly.

Animals↗