Immunohistochemistry of liver and lung of infected IFNAR^-/- mice.

<p>Animals were inoculated i.v. with 10³ FFU of Lassa virus strain AV and euthanized at day 9 p.i. to collect the organs. Sections were stained with anti-Lassa virus NP, anti-Iba-1, anti-iNOS, or anti-CD3 antibodies.</p

Virus titers in organs of IFNAR^-/- mice.

<p>Animals were inoculated i.v. with 10³ FFU of the indicated viruses and euthanized at day 9–10 p.i. to collect the organs. Mean and range are shown (n = 2).</p

Influence of CD4⁺ and CD8⁺ T cells on susceptibility of IFNAR^-/- mice to apathogenic arenaviruses.

<p>CD8⁺ and/or CD4⁺ T cell populations were depleted by intraperitoneal administration of anti-CD8 and/or anti-CD4 on day -3 and day -1 of infection. Groups of three animals were inoculated i.v. with 10³ FFU of the indicated viruses. Mean and standard deviation are shown (n = 3). For AST measurement, blood of the three animals was pooled. The range of viremia below the detection limit of the immunofocusassay as well as the normal reference range of AST in mice [43] are shaded in grey.</p

H/E-stained sections of liver and lung of infected IFNAR^-/- mice.

<p>Animals were inoculated i.v. with 10³ FFU of the indicated viruses and euthanized at day 9–10 p.i. to collect the organs.</p

LASV detection rate by participant.

<p>LASV detection rate by participant.</p

International External Quality Assessment Study for Molecular Detection of Lassa Virus

<div><p>Lassa virus (LASV) is a causative agent of hemorrhagic fever in West Africa. In recent years, it has been imported several times to Europe and North America. The method of choice for early detection of LASV in blood is RT-PCR. Therefore, the European Network for Diagnostics of ‘Imported’ Viral Diseases (ENIVD) performed an external quality assessment (EQA) study for molecular detection of LASV. A proficiency panel of 13 samples containing various concentrations of inactivated LASV strains Josiah, Lib-1580/121, CSF, or AV was prepared. Samples containing the LASV-related lymphocytic choriomeningitis virus (LCMV) and negative sera were included as specificity controls. Twenty-four laboratories from 17 countries (13 European, one African, one Asian, two American countries) participated in the study. Thirteen laboratories (54%) reported correct results, 4 (17%) laboratories reported 1 to 2 false-negative results, and 7 (29%) laboratories reported 3 to 5 false-negative results. This EQA study indicates that most participating laboratories have a good or acceptable performance in molecular detection of LASV. However, several laboratories need to review and improve their diagnostic procedures.</p></div

Summary of the EQA study for molecular detection of LASV.

<p>^a with stabilizer;</p><p>^b not included in score;</p><p>+, virus correctly detected;—negative result; +/–, indeterminate result</p><p>Summary of the EQA study for molecular detection of LASV.</p

List of participating laboratories.

<p>List of participating laboratories.</p

LASV detection rate by sample.

<p>^a with stabilizer;</p><p>^b not included in score</p><p>LASV detection rate by sample.</p

Lassa EN structures, flexibility and metal ion binding.

<p><b>A,</b> Cartoon representation of the Lassa X1 and X3 structures after superposition. The α-helical bundles of X1 and X3 are respectively coloured in light and dark blue. The catalytic loop is highlighted in green and the Mn²⁺ ions of X3 are yellow spheres. The α-helical bundle closes the active site by the indicated rotation (blue arrow). The Lassa X2 structure has the same conformation as X3 (see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005636#ppat.1005636.s005" target="_blank">S5A and S5B Fig</a>). <b>B,</b> The same structure superposition as <b>A</b>, with the active site residues as sticks, the X3 Mn²⁺ metal ions as yellow spheres and the ion coordination indicated by dashed green lines. <b>C,</b> Comparison of the Lassa X1 structure (light blue) and the previously reported Lassa EN structure in complex with Mg²⁺ [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005636#ppat.1005636.ref016" target="_blank">16</a>] (light pink, PDB: 4MIW). The Mg²⁺ ions are shown as cyan spheres. <b>D,</b> The same superposition as <b>C,</b> with the active site residues as sticks and the bridging water molecules as small red spheres. The ion coordination and hydrogen bond network is shown by green dashed lines.</p