HIV-1 Integrase-Targeted Short Peptides Derived from a Viral Protein R Sequence

HIV-1 integrase (IN) inhibitors represent a new class of highly effective anti-AIDS therapeutics. Current FDA-approved IN strand transfer inhibitors (INSTIs) share a common mechanism of action that involves chelation of catalytic divalent metal ions. However, the emergence of IN mutants having reduced sensitivity to these inhibitors underlies efforts to derive agents that antagonize IN function by alternate mechanisms. Integrase along with the 96-residue multifunctional accessory protein, viral protein R (Vpr), are both components of the HIV-1 pre-integration complex (PIC). Coordinated interactions within the PIC are important for viral replication. Herein, we report a 7-mer peptide based on the shortened Vpr (69–75) sequence containing a biotin group and a photo-reactive benzoylphenylalanyl residue, and which exhibits low micromolar IN inhibitory potency. Photo-crosslinking experiments have indicated that the peptide directly binds IN. The peptide does not interfere with IN-DNA interactions or induce higher-order, aberrant IN multimerization, suggesting a mode of action for the peptide that is distinct from clinically used INSTIs and developmental allosteric IN inhibitors. This compact Vpr-derived peptide may serve as a valuable pharmacological tool to identify a potential new pharmacologic site

The properties of hot household hygroscopic materials and their potential use for non-medical facemask decontamination

The wide use of facemasks through the population to prevent SARS-CoV-2 virus transmission, and its resulting mis- or even non-decontamination are challenging the management of the epidemic at a large scale. As a complement to machine-wash that wastes significant amount of water and energy, hot hygroscopic materials could be used to decontaminate non-medical facemasks in household settings. We report the inactivation of a viral load on a facial mask for an exposure of 15 minutes, with the combined effect of heat and humidity under a decaying pattern suggesting straight-forward general public deployment towards a reliable implementation by the population

A Simple and Fast Method to Sequence the Full-Length Spike Gene for SARS-CoV-2 Variant Identification from Patient Samples

Since the beginning of the pandemic, a race has been underway to detect SARS-CoV-2 virus infection (PCR screening, serological diagnostic kits), treat patients (drug repurposing, standard care) and develop a vaccine. After almost a year of active circulation worldwide, SARS-CoV-2 variants have appeared in different countries. Those variants include mutations in multiple regions of the genome, particularly in the spike gene. Because this surface protein is a key player in both the spread of the virus and the efficacy of vaccine strategies, the challenge is to efficiently monitor the appearance of spike mutations in the population. The present work describes a procedure based on the widely available Sanger technology to produce a full-length sequence of the spike gene from patient-derived samples

Resistance to Integrase Inhibitors

Integrase (IN) is a clinically validated target for the treatment of human immunodeficiency virus infections and raltegravir exhibits remarkable clinical activity. The next most advanced IN inhibitor is elvitegravir. However, mutant viruses lead to treatment failure and mutations within the IN coding sequence appear to confer cross-resistance. The characterization of those mutations is critical for the development of second generation IN inhibitors to overcome resistance. This review focuses on IN resistance based on structural and biochemical data, and on the role of the IN flexible loop i.e., between residues G140-G149 in drug action and resistance

Resistance to Integrase Inhibitors

Integrase (IN) is a clinically validated target for the treatment of human immunodeficiency virus infections and raltegravir exhibits remarkable clinical activity. The next most advanced IN inhibitor is elvitegravir. However, mutant viruses lead to treatment failure and mutations within the IN coding sequence appear to confer cross-resistance. The characterization of those mutations is critical for the development of second generation IN inhibitors to overcome resistance. This review focuses on IN resistance based on structural and biochemical data, and on the role of the IN flexible loop i.e., between residues G140-G149 in drug action and resistance

Nucleic Acids Res

Integrase strand transfer inhibitors (INSTIs) are highly effective against HIV infections. Co-crystal structures of the prototype foamy virus intasome have shown that all three FDA-approved drugs, raltegravir (RAL), elvitegravir and dolutegravir (DTG), act as interfacial inhibitors during the strand transfer (ST) integration step. However, these structures give only a partial sense for the limited inhibition of the 3'-processing reaction by INSTIs and how INSTIs can be modified to overcome drug resistance, notably against the G140S-Q148H double mutation. Based on biochemical experiments with modified oligonucleotides, we demonstrate that both the viral DNA +1 and -1 bases, which flank the 3'-processing site, play a critical role for 3'-processing efficiency and inhibition by RAL and DTG. In addition, the G140S-Q148H (SH) mutant integrase, which has a reduced 3'-processing activity, becomes more active and more resistant to inhibition of 3'-processing by RAL and DTG in the absence of the -1 and +1 bases. Molecular modeling of HIV-1 integrase, together with biochemical data, indicate that the conserved residue Q146 in the flexible loop of HIV-1 integrase is critical for productive viral DNA binding through specific contacts with the virus DNA ends in the 3'-processing and ST reactions. The potency of integrase inhibitors against 3'-processing and their ability to overcome resistance is discussed

SARS-CoV-2 transmission via apical syncytia release from primary bronchial epithelia and infectivity restriction in children epithelia

The beta-coronavirus SARS-CoV-2 is at the origin of a persistent worldwide pandemic. SARS-CoV-2 infections initiate in the bronchi of the upper respiratory tract and are able to disseminate to the lower respiratory tract eventually causing acute severe respiratory syndrome with a high degree of mortality in the elderly. Here we use reconstituted primary bronchial epithelia from adult and children donors to follow the infection dynamic following infection with SARS-CoV-2. We show that in bronchial epithelia derived from adult donors, infections initiate in multi-ciliated cells. Then, infection rapidly spread within 24-48h throughout the whole epithelia. Within 3-4 days, large apical syncytia form between multi-ciliated cells and basal cells, which dissipate into the apical lumen. We show that these syncytia are a significant source of the released infectious dose. In stark contrast to these findings, bronchial epithelia reconstituted from children donors are intrinsically more resistant to virus infection and show active restriction of virus spread. This restriction is paired with accelerated release of IFN compared to adult donors. Taken together our findings reveal apical syncytia formation as an underappreciated source of infectious virus for either local dissemination or release into the environment. Furthermore, we provide direct evidence that children bronchial epithelia are more resistant to infection with SARS-CoV-2 providing experimental support for epidemiological observations that SARS-CoV-2 cases’ fatality is linked to age. Significance Statement Bronchial epithelia are the primary target for SARS-CoV-2 infections. Our work uses reconstituted bronchial epithelia from adults and children. We show that infection of adult epithelia with SARS-CoV-2 is rapid and results in the synchronized release of large clusters of infected cells and syncytia into the apical lumen contributing to the released infectious virus dose. Infection of children derived bronchial epithelia revealed an intrinsic resistance to infection and virus spread, probably as a result of a faster onset of interferon secretion. Thus, our data provide direct evidence for the epidemiological observation that children are less susceptible to SARS-CoV-2

Targeting the Integrated Stress Response Kinase GCN2 to Modulate Retroviral Integration

International audienceMultiple viral targets are now available in the clinic to fight HIV infection. Even if this targeted therapy is highly effective at suppressing viral replication, caregivers are facing growing therapeutic failures in patients due to resistance, with or without treatment-adherence glitches. Accordingly, it is important to better understand how HIV and other retroviruses replicate in order to propose alternative antiviral strategies. Recent studies have shown that multiple cellular factors are implicated during the integration step and, more specifically, that integrase can be regulated through post-translational modifications. We have shown that integrase is phosphorylated by GCN2, a cellular protein kinase of the integrated stress response, leading to a restriction of HIV replication. In addition, we found that this mechanism is conserved among other retroviruses. Accordingly, we developed an in vitro interaction assay, based on the AlphaLISA technology, to monitor the integrase-GCN2 interaction. From an initial library of 133 FDA-approved molecules, we identified nine compounds that either inhibited or stimulated the interaction between GCN2 and HIV integrase. In vitro characterization of these nine hits validated this pilot screen and demonstrated that the GCN2-integrase interaction could be a viable solution for targeting integrase out of its active site

Discovery of Novel Integrase Inhibitors Acting outside the Active Site Through High-Throughput Screening

International audienc