Time filter

Source Type

Pozo F.,Institute Salud Carlos III | Lina B.,Institute Of Microbiologie Bat A3 | Andrade H.R.D.,Instituto Nacional Of Saude | Enouf V.,Institute Pasteur Paris | And 5 more authors.
Journal of Clinical Virology | Year: 2013

Two classes of antiviral drugs are licensed in Europe for treatment and prophylaxis of influenza; the M2 ion-channel blockers amantadine and rimantadine acting against type A influenza viruses only and the neuraminidase enzyme inhibitors zanamivir and oseltamivir acting against type A and type B influenza viruses. This guidance document was developed for but not limited to the European Union (EU) and other European Economic Area (EEA) countries on how and when to test for influenza virus antiviral drug susceptibility. It is aimed at clinical and influenza surveillance laboratories carrying out antiviral drug susceptibility testing on influenza viruses from patients suspected of harbouring viruses with reduced susceptibility or for the monitoring of the emergence of such among circulating viruses, respectively. Therefore, the guidance should not be read as a directive or an algorithm for treatment. Monitoring for emergence of influenza viruses with reduced drug susceptibility in hospitalized cases is crucial for decision making on possible changes to antiviral treatment. Therefore, it is important to test for antiviral susceptibility in certain patient groups, such as patients treated with influenza antiviral drugs. It is also important to determine the frequency of viruses with natural (not related to drug use) reduced susceptibility among community and hospitalized cases, as this knowledge is essential for making empirical antiviral treatment decisions. Furthermore, testing of specimens from community influenza patients is needed to determine the frequency of viruses with reduced susceptibility and good viral fitness that are readily transmissible, as they may become dominant among circulating viruses. Phenotypic neuraminidase enzyme inhibition assays are recommended to determine the level of inhibition of the neuraminidase enzyme by antiviral drugs as a measure of drug susceptibility of the virus. Genotypic assays are recommended to identify amino acid substitutions in the neuraminidase and M2 ion-channel proteins that have been associated with reduced antiviral susceptibility previously. By 2012 all circulating seasonal influenza A(H1N1)pdm09 and A(H3N2) viruses were naturally resistant to the M2 ion-channel blockers, so priority should be given to testing for neuraminidase inhibitor susceptibility. © 2013 Elsevier B.V.


Symeonidou I.,Aristotle University of Thessaloniki | Pappa S.,Arisotle University of Thessaloniki | Kourelis A.,Aristotle University of Thessaloniki | Anogeianaki A.,Aristotle University of Thessaloniki | And 3 more authors.
International Journal of Immunopathology and Pharmacology | Year: 2010

The NF-κB pathway gene expression profiles were compared between 10, 20 and 39 days after Trichinella spiralis experimental infection in BALB/c mice. Out of 128 genes, 19 (14.8%) genes were present in non-infected and post-infected mice. The expression of 7 (36.8%) genes was downregulated 10 and 20 days post-infection while 3 (15.8%) genes were upregulated 39 days post-infection. The present study lists the candidate genes of the NF-κB signaling pathway that were commonly and differentially expressed between the specific points of T. spiralis infection, thus suggesting that these genes need to be further investigated to reveal the mechanism of the T. spiralis modulation of the NF-κB signaling pathways. Copyright © by BIOLIFE, s.a.s.


Njouom R.,Center Pasteur du Cameroun | Nerrienet E.,Center Pasteur du Cameroun | Budkowska A.,Institute Pasteur Paris | Maillard P.,Institute Pasteur Paris | And 3 more authors.
Journal of Clinical Virology | Year: 2010

Background: According to previous data, the antibodies produced during natural hepatitis C virus (HCV) infection frequently recognize amino acids 10-43 in the core protein and 1689-1740 or 1921-1940 in the non-structural 4B (NS4B) protein. The reactivity of these peptides with the corresponding antibodies has mainly been evaluated using serum samples from Western countries where HCV genotype 1 (HCV-1) is predominant, and no information is available concerning samples from sub-Saharan countries where high HCV variability has been reported. Objective of this study: To evaluate the performance of HCV core and NS4B peptide-based immunoassays in the serodiagnosis of HCV infection in Cameroon subjects. Study design: Three core and four NS4B-based synthetic peptides derived from HCV genotypes 1b and 2a were designed and tested against a panel of 151 serum samples from Cameroon (40 positive for HCV-1, 32 for HCV-2, 39 HCV-4, and 40 HCV-negative). Results: The three core peptides all demonstrated strong immunoreactivity, regardless of the HCV genotype from which they were derived, with greater than 90% and 92% sensitivity and specificity. In contrast, the NS4B-derived peptides exhibited lower sensitivities (24.3-65.8% depending on the HCV genotype) but higher specificities (100% for all four peptides tested). Conclusions: Our findings indicate that an HCV core peptide could be used for the diagnosis of chronic HCV infection. Among the NS4B peptides tested, a chimeric NS4B peptide encompassing both N- and C-terminal portions of the NS4B protein gave a much better performance than the two component N- and C-terminal peptides used individually. © 2010 Elsevier B.V.


Athanasopoulos A.,Institute of Biosciences and Applications | Boleti H.,Institute Pasteur Hellenique | Scazzocchio C.,Imperial College London | Scazzocchio C.,University Paris - Sud | Sophianopoulou V.,Institute of Biosciences and Applications
Fungal Genetics and Biology | Year: 2013

In the model filamentous fungus Aspergillus nidulans, PilA and PilB, two homologues of the Saccharomyces cerevisiae eisosome proteins Pil1/Lsp1, and SurG, a strict orthologue of Sur7, are assembled and form tightly packed structures in conidiospores. As A. nidulans differs in its reproduction pattern from the Saccharomycotina in that it has the ability to reproduce through two different types of spores, conidiospores and ascospores, the products of the asexual and the sexual cycle respectively, we investigated the eisosome distribution and localization during the sexual cycle. Our results show that core eisosome proteins PilA, PilB and SurG are not expressed in hülle cells or early ascospores, but are expressed in mature ascospores. All eisosomal proteins form punctate structures at the membrane of late ascospores. In mature but quiescent ascospores, PilA forms static punctate structures at the plasma membrane. PilB also was observed at the ascospore membrane as well, with higher concentration at the areas where the two halves of ascospores are joined together. Finally, SurG was localized both at the membrane of ascospores and perinuclearly. In germlings originating from ascospores the punctate structures were shown to be composed only of PilA. PilB is diffused in the cytoplasm and SurG was located in vacuoles and endosomes. This altered localization is identical to that found in germlings originated from conidiospores. In germinated ascospores PilA foci did not colocalise with the highly mobile and transient peripheral punctate structures of AbpA, a marker for sites of clathrin-mediated endocytosis. Deletions of each one or all the three core eisosomal genes do not affect viability or germination of ascospores. In the presence of myriocin - a specific inhibitor of sphingolipid biosynthesis - PilA-GFP foci of ascospore germlings were less numerous and their distribution was significantly altered, suggesting a correlation between PilA foci and sphingolipid biosynthesis. © 2013 Elsevier Inc.


Koros C.,National and Kapodistrian University of Athens | Ioannidis A.,University of Peloponnese | Acquaviva T.,Thriassion Hospital | Zoga M.,National and Kapodistrian University of Athens | And 4 more authors.
In Vivo | Year: 2014

Aim: The pathogenic role of Herpes Simplex Virus (HSV) 1 and 2 in Multiple Sclerosis (MS) still remains obscure. The aim of our study was the assessment of HSV1 and 2 DNA prevalence in the cerebrospinal fluid (CSF) of MS patients compared to patients with other neurological disorders (OND). Materials and Methods: HSV1 and HSV2 DNA detection in the CSF of patients was performed by real time polymerase chain reaction (PCR). Results: The genome of HSV1 was present in the CSF of 4.7% of MS patients (4 out of 85), while HSV2 was not detected in any patient. In the sub-group of OND patients, HSV1 was detected in 7.9% of patients (3 out of 38) and HSV2 was detected in 5.3% of patients (2 out of 38). Conclusion: Our data are in accordance with a limited number of previous reports, supporting a prevalence of HSV1 genome in less than 5% of MS patients.


PubMed | Thriassion Hospital, Institute Pasteur Hellenique, University of Peloponnese and National and Kapodistrian University of Athens
Type: Journal Article | Journal: In vivo (Athens, Greece) | Year: 2014

The pathogenic role of Herpes Simplex Virus (HSV) 1 and 2 in Multiple Sclerosis (MS) still remains obscure. The aim of our study was the assessment of HSV1 and 2 DNA prevalence in the cerebrospinal fluid (CSF) of MS patients compared to patients with other neurological disorders (OND).HSV1 and HSV2 DNA detection in the CSF of patients was performed by real time polymerase chain reaction (PCR).The genome of HSV1 was present in the CSF of 4.7% of MS patients (4 out of 85), while HSV2 was not detected in any patient. In the sub-group of OND patients, HSV1 was detected in 7.9% of patients (3 out of 38) and HSV2 was detected in 5.3% of patients (2 out of 38).Our data are in accordance with a limited number of previous reports, supporting a prevalence of HSV1 genome in less than 5% of MS patients.


Boleti H.,Molecular Virology Laboratory | Boleti H.,Institute Pasteur Hellenique | Smirlis D.,Institute Pasteur Hellenique | Dalagiorgou G.,Molecular Virology Laboratory | And 3 more authors.
Molecular Membrane Biology | Year: 2010

The Hepatitis C virus (HCV) NS4B protein, a multispanning endoplasmic reticulum (ER) membrane protein, generates intracellular rearrangements of ER-derived membranes, essential for HCV replication. In this study, we characterized NS4B elements involved in the process of targeting, association and retention in the ER membrane. We investigated the localization and membrane association of a number of C-or N-terminal NS4B deletions expressed as GFP chimeras by iochemical and fluorescence microscopy techniques. A second set of GFP-NS4B chimeras containing the plasma membrane ecto-ATPase CD39 at the C-terminus of each NS4B deletion mutant was used to further examine the role of N-terminal NS4B sequences in ER retention. Several structural elements, besides the first two transmembrane domains (TMs), within the NS4B N-terminal half (residues 1-130) were found to mediate association of the NS4B-GFP chimeras with ER membranes. Both TM1 and TM2 are required for ER anchoring and retention but are not sufficient for ER retention. Sequences upstream of TM1 are also required. These include two putative amphipathic a-helices and a Leucine Rich Repeat-like motif, a sequence highly conserved in all HCV genotypes. The N-terminal 55peptidic sequence, containing the 1st amphipathic helix, mediates association of the 55N-GFP chimera with cellular membranes including the ER, but is dispensable for ER targeting of the entire NS4B molecule. Importantly, the C-terminal 70peptidic sequence can associate with membranes positive for ER markers in the absence of any predicted TMs. In conclusion, HCV NS4B targeting and retention in the ER results from the concerted action of several NS4B structural elements.


Symeonidou I.,Aristotle University of Thessaloniki | Hatzistilianou M.,Aristotle University of Thessaloniki | Papadopoulos E.,Aristotle University of Thessaloniki | Dovas C.I.,Aristotle University of Thessaloniki | And 5 more authors.
European Journal of Inflammation | Year: 2011

The prevalence of canine leishmaniosis (CanL) infection in an enzootic area is considerably higher than the overall prevalence of the disease, suggesting a role of host genetics related to the outcome of the disease. It is accepted that one determining factor for the outcome of CanL is the type of the triggered immune response, which seems to be genetically determined. TNF-α is a cytokine which plays a crucial role during the immune response against Leishmania parasites. In the present study a case-control study with 20 resistant and 20 susceptible dogs was performed. The distribution of breeds was equal in both groups. By Sanger method the nucleotide sequence upstream the Open Reading Frame of the canine TNF-α gene was determined and four polymorphisms were identified (-40 C/A, -1134 T/G, -1150 T/C και -1243 C/G). Statistical analysis showed that the polymorphism TNF-α -40 C/A is correlated with susceptibility to CanL, while the polymorphism TNF-α -1243 C/G is correlated with resistance to CanL. Further statistical analysis, regarding the possible correlation of gender as well as clinical manifestations of the disease with the above-mentioned polymorphisms of the TNF-α gene, showed no significant findings. Further analysis of the above polymorphisms, as well as identification of more polymorphisms in candidate genes, is required to provide a better understanding of the complex underlying immune response in CanL. Copyright © by BIOLIFE, s.a.s.


Symeonidou I.,Aristotle University of Thessaloniki | Kourelis A.,Aristotle University of Thessaloniki | Frydas I.,Aristotle University of Thessaloniki | Karagouni E.,Institute Pasteur Hellenique | And 3 more authors.
Journal of Biological Regulators and Homeostatic Agents | Year: 2010

NF-κB is implicated in lymphocyte development, maturation, proliferation and survival. This inducible transcription factor is widely expressed by virtually all cell types. In mammals, the genes rela, relb, crel, nfκB1, and nfκB2 encode the five NF-κB protein family members RelA (p65), RelB, c-Rel, p50, and p52, respectively, which form homo- and heterodimeric DNA-binding complexes capable of regulating target gene transcription of specific biological responses differentially. NF-κB regulates the expression of a wide variety of genes that play critical roles in innate and adaptive immune responses, is strongly linked to the inhibition of apoptosis, and contributes to tumor growth, metastasis, and chemoresistance. Parasites have targeted several parts of the NF-κB pathway, allowing them to interfere with the transcription of immune response genes. The biology of different parasites is critical in influencing the patterns and kinetics of NF-κB activity and thereby the development of subsequent immune responses. Copyright © by BIOLIFE, s.a.s.

Loading Institute Pasteur Hellenique collaborators
Loading Institute Pasteur Hellenique collaborators