Biology subjects

Komarova, A.

Publications and source records attributed to Komarova, A..

4 recordsLinked to original sources

bioRxiv2025

A modified oncolytic measles virus exhibits strong immunotherapeutic potential through RIG-I activation by defective viral genomes

Oncolytic viruses can destroy tumors directly or by activating antitumor immunity, but balancing safety with potent immune stimulation remains challenging. Here, we show that deletion of the measles virus C protein, a key viral antagonist of innate immunity, reprograms the live-attenuated vaccine strain into a RIG-I-driven cancer immunotherapy. The resulting virus, MVdeltaC, accumulates defective viral genomes that activate RIG-I/MAVS signaling and trigger robust type I interferon and pro-inflammatory cytokine responses. MVdeltaC kills tumor cells more rapidly and efficiently than the parental virus and induces hallmarks of immunogenic cell death, including HMGB1 release and dendritic cell maturation. Intratumoral administration in immunocompetent mice bearing syngeneic neuroblastoma induced complete tumor regression in 90% of animals and established long-term antitumor memory. Antitumor responses were dependent on CD8 T and NK cells and were further enhanced by anti-CTLA-4 therapy or CD4 T-cell depletion. Prior measles immunization accelerated tumor clearance, indicating vaccine-boosted responses. MVdeltaC also controlled the growth of human mesothelioma, melanoma, and triple-negative breast cancer xenografts and patient-derived tumors in immunodeficient models. These findings establish MVdeltaC as a clinically ready, broad-spectrum immunotherapeutic that links RIG-I activation through defective viral genome generation to elicit potent and durable antitumor immunity. IMPACT StatementA modified measles virus lacking a viral innate immunity antagonist triggers potent antitumor responses via RIG-I sensing of defective viral genomes, revealing a new strategy for cancer immunotherapy.

immunology↗

bioRxiv2022

Recognition of copy-back defective interfering rabies virus genomes by RIG-I triggers the antiviral response against vaccine strains

Rabies virus (RABV) is a lethal neurotropic virus that causes 60,000 human deaths every year around the world. A typical feature of RABV infection is the suppression of type I and III interferon (IFN)-mediated antiviral response. However, molecular mechanisms leading to RABV sensing by RIG-I-like receptors (RLR) to initiate IFN signaling remain elusive. Here, we showed that RABV RNAs are recognized by RIG-I (retinoic acid-inducible gene I) sensor resulting in an IFN response of the infected cells but that this global feature was differently modulated according to the type of RABV used. RNAs from pathogenic RABV strain, THA, were poorly detected in the cytosol by RIG-I and therefore mediated a weak antiviral response. On the opposite, we revealed a strong interferon activity triggered by the RNAs of the attenuated RABV vaccine SAD strain mediated by RIG-I. Using next-generation sequencing (NGS) combined with bioinformatics tools, we characterized two major 5copy-back defective interfering (5cb DI) genomes generated during SAD replication. Furthermore, we identified a specific interaction of 5cb DI genomes and RIG-I that correlated with a high stimulation of the type I IFN signaling. This study indicates that RNAs from a wild-type RABV poorly activate the RIG-I pathway, while the presence of 5cb DIs in vaccine SAD strain serves as an intrinsic adjuvant that strengthens its efficiency by enhancing RIG-I detection and therefore strongly stimulates the IFN response. HighlightsO_LIRABV pathogenic strain replication in vitro is characterized by the absence of defective interfering genomes thus induces a weak RLR-mediated innate immunity antiviral response. C_LIO_LIRABV vaccine attenuated strain shows a high release of 5 copy-back defective interfering genomes during replication in vitro and therefore enhances a strong antiviral response upon infection. C_LIO_LIRIG-I is the main sensor for RABV RNA detection within cells. C_LI

microbiology↗

bioRxiv2020

Global BioID-based SARS-CoV-2 proteins proximal interactome unveils novel ties between viral polypeptides and host factors involved in multiple COVID19-associated mechanisms

The worldwide SARS-CoV-2 outbreak poses a serious challenge to human societies and economies. SARS-CoV-2 proteins orchestrate complex pathogenic mechanisms that underlie COVID-19 disease. Thus, understanding how viral polypeptides rewire host protein networks enables better-founded therapeutic research. In complement to existing proteomic studies, in this study we define the first proximal interaction network of SARS-CoV-2 proteins, at the whole proteome level in human cells. Applying a proximity-dependent biotinylation (BioID)-based approach greatly expanded the current knowledge by detecting interactions within poorly soluble compartments, transient, and/or of weak affinity in living cells. Our BioID study was complemented by a stringent filtering and uncovered 2,128 unique cellular targets (1,717 not previously associated with SARS-CoV-1 or 2 proteins) connected to the N- and C-ter BioID-tagged 28 SARS-CoV-2 proteins by a total of 5,415 (5,236 new) proximal interactions. In order to facilitate data exploitation, an innovative interactive 3D web interface was developed to allow customized analysis and exploration of the landscape of interactions (accessible at http://www.sars-cov-2-interactome.org/). Interestingly, 342 membrane proteins including interferon and interleukin pathways factors, were associated with specific viral proteins. We uncovered ORF7a and ORF7b protein proximal partners that could be related to anosmia and ageusia symptoms. Moreover, comparing proximal interactomes in basal and infection-mimicking conditions (poly(I:C) treatment) allowed us to detect novel links with major antiviral response pathway components, such as ORF9b with MAVS and ISG20; N with PKR and TARB2; NSP2 with RIG-I and STAT1; NSP16 with PARP9-DTX3L. Altogether, our study provides an unprecedented comprehensive resource for understanding how SARS-CoV-2 proteins orchestrate host proteome remodeling and innate immune response evasion, which can inform development of targeted therapeutic strategies.

systems biology↗

bioRxiv2019

Y-RNAs Lead an Endogenous Program of RIG-I Agonism Mobilized upon RNA Virus Infection and Targeted by HIV

Pattern recognition receptors (PRRs) protect against host invasion by detecting specific molecular patterns found in pathogens and initiating an immune response. While microbial-derived PRR ligands have been extensively characterized, the contribution and relevance of endogenous ligands to PRR activation during viral infection remain overlooked. In this work, we characterize the landscape of endogenous ligands that engage RIG-I-like receptors (RLRs) upon infection by a positive-sense RNA virus, a negative-sense RNA virus or a retrovirus. We found that several endogenous RNAs transcribed by RNA polymerase 3 (Pol3) specifically engage RLRs, and in particular the family of small non-coding repeats Y-RNAs, which presents the highest affinity as RIG-I ligands. We show that this recognition is dependent on Y-RNA mimicking viral secondary structure and its 5-triphosphate extremity. Further, we found that HIV-1 infection triggers a VPR-dependent downregulation of RNA triphosphatase DUSP11 in vitro and in vivo, leading to an increase of Y-RNA 5-triphosphorylation that enables their immunogenicity. Importantly, we show that altering DUSP11 expression is sufficient to induce a type-I interferon and T cell activation transcriptional program associated with HIV-1 infection. Overall, our work uncovers the critical contribution of endogenous repeat RNAs ligands to antiviral immunity and demonstrates the role of this pathway in HIV-1 infection.

immunology↗