Biology subjects

Kilbourne, J.

Publications and source records attributed to Kilbourne, J..

5 recordsLinked to original sources

bioRxiv2026

Atypical myxomatosis in European rabbits is caused by the recombinant myxoma virus involved in species jumping into hares

Myxoma virus (MYXV), a member of the Leporipoxvirus genus (species Leporipoxvirus myxoma; family Poxviridae), causes a highly lethal disease known as myxomatosis in European rabbits. In late 2018, a new natural MYXV isolate, MYXV-Tol (a.k.a. hare MYXV; ha-MYXV), emerged and caused myxomatosis-like disease with high mortality in Iberian hares, European brown hares, and European rabbits. This variant contains an approximately 2.8-kb insertion of a recombination cassette within the M009L gene encoding four additional genes, including the C7-like host range gene, M159L. M159 is essential for replication of MYXV-Tol in hare cells and is likely a key determinant of its pathogenicity in both hares and rabbits. Here, we compared the pathogenicity of wild-type MYXV-Tol (vMyx-Tol), an M159 deletion strain (vMyx-Tol-M159KO), and the classical MYXV-Lau strain (vMyx-Lau) in European rabbits. All three viruses caused systemic disease; however, vMyx-Tol and vMyx-Tol-M159KO produced clinical signs distinct from classical myxomatosis. Infection with vMyx-Tol and vMyx-Tol-M159KO was characterized by the absence of the typical primary and secondary nodular lesions, and caused severe edema, marked fluid accumulation, lymphocyte infection, and significantly reduced or no virus-neutralizing antibody responses. The disease caused by both vMyx-Tol and vMyx-Tol-M159KO progressed rapidly within 9-11 days, resulting in animals reaching humane euthanasia endpoints like vMyx-Lau. Deletion of M159 did not significantly alter MYXV-Tol pathogenicity in rabbits. Collectively, these findings demonstrate that MYXV-Tol has evolved to cause an atypical, amyxomatous-like acute to hyperacute disease in European rabbits and likely in hares. SignificanceNatural evolution enables viruses to cross species barriers and adapt to new hosts. Myxoma virus (MYXV), released in the 1950s in Australia and Europe as a biocontrol agent against European rabbits, became a classic model for real-time monitoring of virus evolution, virulence, and host adaptation. Although MYXV is typically host-restricted, a newly emerged natural isolate, MYXV-Tol, causes lethal disease in both hares and rabbits. Here, we show that MYXV-Tol induces an atypical, amyxomatous-like disease characterized by the absence of nodular lesions, severe edema, lymphocyte infection, and markedly reduced virus-neutralizing antibody responses. These findings reveal previously unrecognized virus-host interactions that shape disease outcome and provide new insight into the mechanisms driving viral adaptation and evolution.

microbiology↗

bioRxiv2024

Systemic Dosing of Virus-derived Serpin Improves Survival and Immunothrombotic Damage in Murine Colitis

Inflammatory bowel disease (IBD) is potentially life-threatening, with risk of bleeding, clotting, infection, sepsis, cancer and toxic megacolon. Systemic and local immune and coagulation dysfunction increase IBD severity. Current treatments are partially effective, but there is no definitive cure. Serine protease cascades activate thrombotic, thrombolytic and complement pathways and are regulated by inhibitors, serpins. Viruses encode proteins evolved from endogenous central regulatory pathways. A purified secreted Myxomavirus-derived serpin, Serp-1, dosed as a systemic anti-inflammatory drug, has proven efficacy in vascular and inflammatory disorders. PEGylated Serp-1 protein (PEGSerp-1) has improved efficacy in lupus and SARS-CoV-2 models. We examined PEGSerp-1 treatment in a mouse Dextran Sodium Sulfate (DSS) colitis model. Prophylactic PEGSerp-1 significantly improved survival in acute severe 4-5% DSS colitis, reducing inflammation and crypt damage in acute 4-5% DSS induced colitis and when dosed as a chronic delayed treatment for recurrent 2% DSS colitis. PEGSerp-1 reduced iNOS+ M1 macrophage invasion, damage to crypt architecture and vascular inflammation with decreased uPAR, fXa, fibrinogen and complement activation. This work supports PEGSerp-1 as a tissue targeting serpin therapeutic.

molecular biology↗

bioRxiv2022

A novel anti-cancer therapy with nuclear export inhibitor Selinexor in combination with oncolytic myxoma virus

Oncolytic viruses exploited for cancer therapy are developed to selectively infect, replicate, and kill cancer cells to stop tumor growth. However, in some cancer cells, oncolytic viruses are often limited in completing their full replication cycle, making progeny virions, and/or spread in the tumor bed due to the heterogeneous cell types within the tumor bed. Here we report that nuclear export pathway regulates oncolytic myxoma virus (MYXV) infection and cytoplasmic viral replication in a subclass of human cancer cell types where virus replication is restricted. Inhibition of CRM1/XPO-1 nuclear export pathway with nuclear export inhibitors can overcome this restriction by trapping restriction factors in the nucleus and allow significantly enhanced virus replication and killing of human cancer cells. Furthermore, knockdown of CRM1/XPO-1 significantly enhanced MYXV replication in restrictive human cancer cells and reduced the formation of anti-viral granules associated with RNA helicase DHX9. Both in vitro and in vivo, we demonstrate that the approved CRM1 inhibitor drug Selinexor enhances the replication of MYXV and cell killing of diverse human cancer cells. In the xenograft tumor model in NSG mice, combination therapy with Selinexor plus MYXV significantly reduced tumor burden and enhanced the survival of animals. Additionally, we performed global scale proteomic analysis of nuclear and cytosolic proteins in human cancer cells to identify the host and viral proteins that are upregulated or downregulated by different treatments. These results for the first time indicate that Selinexor in combination with oncolytic MYXV can be used as potential new anti-cancer therapy

microbiology↗

bioRxiv2020

A highly expressing, soluble, and stable plant-made IgG fusion carrying Zika virus envelope domain III elicits potent immunogenic responses in mice without adjuvant

Therapeutics based on fusing a protein of interest to the IgG Fc domain have been enormously successful, though fewer studies have investigated the vaccine potential of IgG fusions. In this study, we systematically compared the key properties of seven different plant-made human IgG1 fusion vaccine candidates using Zika virus (ZIKV) envelope domain III (ZE3) as a model antigen. Complement protein C1q binding of the IgG fusions was enhanced by: 1) antigen fusion to the IgG N-terminus; 2) removal of the IgG light chain or Fab regions; 3) addition of hexamer-inducing mutations in the IgG Fc; 4) adding a self-binding epitope tag to create recombinant immune complexes (RIC); or 5) producing IgG fusions in plants that lack plant-specific {beta}1,2-linked xylose and 1,3-linked fucose N-linked glycans. We also characterized the expression, solubility, and stability of the IgG fusions. By optimizing immune complex formation, a potently immunogenic vaccine candidate with improved solubility and high stability was produced at 1.5 mg IgG fusion per g leaf fresh weight. In mice, the IgG fusions elicited high titers of Zika-specific antibodies which neutralized ZIKV using only two doses without adjuvant, reaching up to 150-fold higher antibody titers than ZE3 antigen alone. We anticipate these findings will be broadly applicable to the creation of other vaccines and antibody-based therapeutics. Highlights O_LIA modified immune complex has high expression, solubility, stability, and immunogenicity. C_LIO_LIAntigen immunogenicity is improved up to 150-fold by fusion to plant-made IgGs. C_LIO_LIHigh serum IgG titers >1:500,000 were achieved with only two doses without adjuvant. C_LI

immunology↗

bioRxiv2020

Synthetic Maturation of Multilineage Human Liver Organoids via Genetically Guided Engineering

Pluripotent stem cell (PSC)-derived organoids are emerging as novel human-based microphysiological models but display immature phenotypes with limited subsets of endothelial or stromal cells. Here we demonstrate that in vitro manipulation of gene regulatory networks (GRNs) in PSC-derived liver organoids selected either through computational analysis or targeted tissue design can advance tissue maturation in vitro. Through an unbiased comparison with the genetic signature of mature livers, we identify downregulated GRNs in fetal liver organoids compared to adult livers. We demonstrate that overexpression of PROX1 and ATF5, together with targeted CRISPR-based transcriptional activation of endogenous CYP3A4, drives maturation in vitro. Single cell analyses reveal hepatobiliary-, endothelial-, and stellate-like cell populations. The engineered organoids demonstrate enhanced vasculogenesis, capture native liver characteristics (e.g. FXR signaling, CYP3A4 activity), and exhibit therapeutic potential in mice. Collectively, our approach provides a genetically guided framework for engineering developmentally advanced multilineage tissues from hiPSCs. HIGHLIGHTSO_LIIn vitro tissue maturation via genetically encoded molecular programs C_LIO_LIComputational analysis to identify maturation transcription factors in liver organoids C_LIO_LIPromoting vascularization of organoids via genetically encoded molecular programs C_LIO_LISingle cell analysis of parenchymal and non-parenchymal cells C_LIO_LIModeling of native liver functions and in vivo therapeutic potential C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=168 HEIGHT=200 SRC="FIGDIR/small/087445v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@6ec32aorg.highwire.dtl.DTLVardef@1cf2eeforg.highwire.dtl.DTLVardef@1128748org.highwire.dtl.DTLVardef@16fb5a7_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗