Absence of Resistance Mutations in the Integrase Coding Region among ART-Experienced Patients in the Republic of the Congo

Background: HIV infects around one hundred thousand patients in the Republic of the Congo. Approximately 25% of them receive an antiretroviral treatment; current first-line regimens include two NRTIs and one NNRTI, reverse transcriptase inhibitors. Recently, protease inhibitors (PIs) were also introduced as second-line therapy upon clinical signs of treatment failure. Due to the limited number of molecular characterizations and amount of drug resistance data available in the Republic of the Congo, this study aims to evaluate the prevalence of circulating resistance mutations within the pol region. Methods: HIV-positive, ART-experienced patients have been enrolled in four semi-urban localities in the Republic of the Congo. Plasma samples were collected, and viral RNA was extracted. The viral load for each patient was evaluated by RT-qPCR, following the general diagnostic procedures of the University Hospital of Bordeaux. Finally, drug resistance genotyping and phylogenetic analysis were conducted following Sanger sequencing of the pol region. Results: A high diversity of HIV-1 strains was observed with many recombinant forms. Drug resistance mutations in RT and PR genes were determined and correlated to HAART. Because integrase inhibitors are rarely included in treatments in the Republic of the Congo, the prevalence of integrase drug resistance mutations before treatment was also determined. Interestingly, very few mutations were observed. Conclusions: We confirmed a high diversity of HIV-1 in the Republic of the Congo. Most patients presented an accumulation of mutations conferring resistance against NRTIs, NNRTIs and PIs. Nonetheless, the absence of integrase mutations associated with drug resistance suggests that the introduction of integrase inhibitors into therapy will be highly beneficial to patients in the Republic of the Congo

Potential antiviral effects of pantethine against SARS-CoV-2

Abstract SARS-CoV-2 interacts with cellular cholesterol during many stages of its replication cycle. Pantethine was reported to reduce total cholesterol levels and fatty acid synthesis and potentially alter different processes that might be involved in the SARS-CoV-2 replication cycle. Here, we explored the potential antiviral effects of pantethine in two in vitro experimental models of SARS-CoV-2 infection.Pantethine reduced the infection of cells by SARS-CoV-2 in both preinfection and postinfection treatment regimens. Accordingly, cellular expression of the viral spike and nucleocapsid proteins was substantially reduced, and we observed a significant reduction in viral copy numbers in the supernatant of cells treated with pantethine. In addition, pantethine inhibited the infection-induced increase in TMPRSS2 and HECT E3 ligase expression in infected cells as well as the increase in antiviral interferon-beta response and inflammatory gene expression in Calu-3a cells. Our results demonstrate that pantethine, which is well tolerated in humans, was very effective in controlling SARS-CoV-2 infection and might represent a new therapeutic drug that can be repurposed for the prevention or treatment of COVID-19 and long COVID syndrome

Epidémiologie des accidents de plongée survenus en région marseillaise de 2000 à 2009

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocSudocFranceF

Etude de l'intégrase de VIH-1 et du 93del (à la recherche de nouveaux inhibiteurs dans la lutte contre le SIDA)

Le virus de l'immunodéficience humaine de type 1 est un virus infection responsable d'une pandémie incurable. Les traitements actuels permettent, malgré des effets secondaires importants, de contenir la maladie associée, le SIDA. Nous avons développé au laboratoire une stratégie combinatoire (SELEX) dans le but d'isoler de petits ODN présentant une haute affinité pour la RNase H. Gardant en tête que le domaine RNase H et le core catalytique de l'IN soont structuralement proches, ces aptamères ont été testés pour leur capacité à inhiber l'IN. Le 93del inhibe spécifiquement les activités in vitro de l'IN mais également la réplication virale dans le contexte de cellules humaines infectées. Le mécanisme d'action ex vivo de cet inhibiteur a été étudié. La quantification des différents acides nucléiques viraux montre que le 93del a une action multimodale sur la réplication virale (entrée, transcription inverse, intégration). L'étude de l'entrée du 93del dans les cellules humaines révèle que le virus est capable d'augmenter l'entrée de l'inhibiteur dans différentes lignées de manière indépendante du CD4. Pour étudier spécifiquement le mécanisme d'inhibition du 93del dans le milieu intracellulaire, des expériences de transfections ont été réalisées. Dans ces conditions, le 93del inhibe l'étape d'intégration de manière plus spécifique. D'un autre côté, les petits ligands comme le 93del, peuvent être utilisés pour stabiliser l'IN dans des essais de cristallisation. Plusieurs cristaux d'IN en complexe ou non avec le 93del ont été obtenus. La résolution de la structure de l'IN entière sauvage serait alors une avancée importante permettant l'élaboration de nouveaux inhibiteurs.Human Immunodeficiency Virus type 1 (HIV-1) is a pandemic infectious virus. Incurable disease associate can almost be contained with several treatments. Secondary effects are important and resistant virus appears quickly. We developed in the laboratory combinatorial strategies (SELEX) to isolate ODN with high affinity for RNase H. Keeping in mind that RNAse H and IN core are structurally homologous, ODN were tested in IN inhibition assays. 93 del (dimeric G quadraduplex) inhibit specifically in vitro IN activities and is able to inhibit HIV replication in human infected cells. This ex vivo mechanism of inhibition by 93del was studied. 93del seems to inhibit early steps of replication in a multi-target way (entry, reverse transcription and integration). 93del entry in human cells was then evaluated. HIV-1 viral particles enhance ODN entrance in several cells line in a CD4 independent manner. Transfection of 93del was performed prior to infection. In these conditions, we can observe diminution of viral DNA integrated whereas total DNA keep constant. A new step in this study will be to determinate 93del availability in vivo and in a viral context to see if the molecule in current form could be attractive for therapy. Short ligands like ODN can be used to stabilize IN in crystallization assays. Entire IN without mutation was prepared in S. cerevisiae. Several crystals (enzyme alone or in complex with 93del) were obtained. Resolution of the IN structure would be an important step to design specific inhibitor more easily.BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

Biochimie

During clinical trials, a number of fully characterized molecules are dropped along the way because they do not provide enough benefit for the patient. Some of them show limited side effects and might be of great use for other applications. AS1411 is a nucleolin-targeting aptamer that underwent phase II clinical trials as anticancer agent. Here, we show that AS1411 exhibits extremely potent antiviral activity and is therefore an attractive new lead as anti-HIV agent

Sci Rep

Mosquito- and tick-borne pathogens including Chikungunya, Dengue, Japanese encephalitis, West Nile, Yellow fever and Zika virus, represent a new economic and public health challenge. In the absence of effective vaccines and specific therapies, only supportive regimens are administrated for most of these infections. Thus, the development of a targeted therapy is mandatory to stop the rapid progression of these pathogens and preoccupant associated burdens such as Guillain-Barre syndrome, microcephaly. For this, it is essential to develop biochemical tools to help study and target key viral enzymes involved in replication such as helicase complexes, methyl-transferases and RNA-dependent RNA polymerases. Here, we show that a highly purified ZIKV polymerase domain is active in vitro. Importantly, we show that this isolated domain is capable of de novo synthesis of the viral genome and efficient elongation without terminal nucleotide transferase activity. Altogether, this isolated polymerase domain will be a precious tool to screen and optimize specific nucleoside and non-nucleoside inhibitors to fight against Zika infections

Activities, crystal structures, and molecular dynamics of dihydro-1H-isoindole derivatives, inhibitors of HIV-1 integrase

Based on a series of lactam and phthalimide derivatives that inhibit HIV-1 integrase, we developed a new derivative, XZ-259, with biochemical and antiviral activities comparable to raltegravir. We determined the crystal structures of XZ-259 and four other derivatives in complex with the prototype foamy virus intasome. The compounds bind at the integrase-Mg(2+)-DNA interface of the integrase active site. In biochemical and antiviral assays, XZ-259 inhibits raltegravir-resistant HIV-1 integrases harboring the Y143R mutation. Molecular modeling is also presented suggesting that XZ-259 can bind in the HIV-1 intasome with its dimethyl sulfonamide group adopting two opposite orientations. Molecular dynamics analyses of the HIV-1 intasome highlight the importance of the viral DNA in drug potency