Biology subjects

Queval, C. J.

Publications and source records attributed to Queval, C. J..

3 recordsLinked to original sources

bioRxiv2025

Enhancing the efficiency of oncolytic vaccinia virus for ovarian cancer treatment

Vaccinia virus, known for its clinical safety has a tropism for primary and metastatic tumours as well as ovarian tissue. Consequently, oncolytic approaches with recombinant vaccinia viruses have emerged as attractive agents against ovarian cancer. Unfortunately, oncolytic vaccinia monotherapies are yet to live up to their potential promise. Given this, there is a need to identify combination agents that improve the effectiveness of vaccinia in ovarian cancer treatment. We screened 9,000 compounds to identify drugs that enhance the ability of a recombinant vaccinia virus lacking VGF and F1 ({Delta}VF) to induce death of ID8 Trp53-/- murine ovarian cancer cells. We identified a class of tubulin polymerisation inhibitors including vinorelbine. The combination of vinorelbine and vaccinia induces ID8 Trp53-/- cell death via apoptosis. In a syngeneic mouse model of high grade serous ovarian carcinoma, {Delta}VF virus lacking the viral thymidine kinase (TK), armed with GM-CSF and expressing NeonGreen ({Delta}VFTK-NG-GM-CSF) is tumour specific. A combination of the {Delta}VFTK-NG-GM-CSF virus with vinorelbine prolongs mouse survival compared to the treatment of mice with either agent alone. Our study suggests vinorelbine is a promising agent to combine with oncolytic vaccinia virus approaches for the management of ovarian cancer.

cancer biology↗

bioRxiv2020

Macrophage-specific responses to human- and animal-adapted tubercle bacilli reveal pathogen and host factors driving multinucleated cell formation

The Mycobacterium tuberculosis complex (MTBC) is a group of related pathogens that cause tuberculosis (TB) in mammals. MTBC species are distinguished by their ability to sustain in distinct host populations. While Mycobacterium bovis (Mbv) sustains transmission cycles in cattle and wild animals and causes zoonotic TB, M. tuberculosis (Mtb) affects human populations and seldom causes disease in cattle. However, the host and pathogen determinants driving host tropism between MTBC species are still unknown. Macrophages are the main host cell that encounters mycobacteria upon initial infection and we hypothesised that early interactions between the macrophage and mycobacteria influence species-specific disease outcome. To identify factors that contribute to host tropism, we analysed both blood-derived primary human and bovine macrophages (hM{phi} or bM{phi}, respectively) infected with Mbv and Mtb. We show that Mbv and Mtb reside in different cellular compartments and differentially replicate in hM{phi} whereas both Mbv and Mtb efficiently replicate in bM{phi}. Specifically, we show that out of the four infection combinations, only the infection of bM{phi} with Mbv promoted the formation of multinucleated cells (MNCs), a hallmark of tuberculous granulomas. Mechanistically, we demonstrate that both MPB70 from Mbv and extracellular vesicles released by Mbv-infected bM{phi} promote macrophage multi-nucleation. Importantly, we extend our in vitro studies to show that granulomas from Mbv-infected but not Mtb-infected cattle contained higher numbers of MNCs. Our findings implicate MNC formation in the contrasting pathology between Mtb and Mbv for the bovine host, and identify MPB70 from Mbv and extracellular vesicles from bM{phi} as mediators of this process.

microbiology↗

bioRxiv2019

Mycobacterium tuberculosis cording in the cytosol of live lymphatic endothelial cells

The ability of Mycobacterium tuberculosis to form serpentine cords is intrinsically related to its virulence, but specifically how M. tuberculosis cording contributes to pathogenesis remains obscure. We show that several M. tuberculosis clinical isolates form intracellular cords in primary human lymphatic endothelial cells (hLEC) in vitro and also in the lymph nodes of patients with tuberculosis. We identified via RNA-seq a transcriptional programme in hLEC that activates cellular pro-survival and cytosolic surveillance of intracellular pathogens pathways. Consistent with this, cytosolic access of hLEC is required for intracellular M. tuberculosis cording; and cord formation is dependent on the M. tuberculosis ESX-1 type VII secretion system and the mycobacterial lipid PDIM. Finally, we show that M. tuberculosis cording is a novel size-dependent mechanism used by the pathogen to evade xenophagy in the cytosol of endothelial cells. These results provide a mechanism that explains the long-standing association between M. tuberculosis cording and virulence.

cell biology↗