Publications by authors named "Kelly Locke"

12 Publications

  • Page 1 of 1

Novel role of SARM1 mediated axonal degeneration in the pathogenesis of rabies.

PLoS Pathog 2020 02 18;16(2):e1008343. Epub 2020 Feb 18.

CSIRO Australian Animal Health Laboratory, East Geelong, Victoria, Australia.

Neurotropic viral infections continue to pose a serious threat to human and animal wellbeing. Host responses combatting the invading virus in these infections often cause irreversible damage to the nervous system, resulting in poor prognosis. Rabies is the most lethal neurotropic virus, which specifically infects neurons and spreads through the host nervous system by retrograde axonal transport. The key pathogenic mechanisms associated with rabies infection and axonal transmission in neurons remains unclear. Here we studied the pathogenesis of different field isolates of lyssavirus including rabies using ex-vivo model systems generated with mouse primary neurons derived from the peripheral and central nervous systems. In this study, we show that neurons activate selective and compartmentalized degeneration of their axons and dendrites in response to infection with different field strains of lyssavirus. We further show that this axonal degeneration is mediated by the loss of NAD and calpain-mediated digestion of key structural proteins such as MAP2 and neurofilament. We then analysed the role of SARM1 gene in rabies infection, which has been shown to mediate axonal self-destruction during injury. We show that SARM1 is required for the accelerated execution of rabies induced axonal degeneration and the deletion of SARM1 gene significantly delayed axonal degeneration in rabies infected neurons. Using a microfluidic-based ex-vivo neuronal model, we show that SARM1-mediated axonal degeneration impedes the spread of rabies virus among interconnected neurons. However, this neuronal defense mechanism also results in the pathological loss of axons and dendrites. This study therefore identifies a potential host-directed mechanism behind neurological dysfunction in rabies infection. This study also implicates a novel role of SARM1 mediated axonal degeneration in neurotropic viral infection.
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http://dx.doi.org/10.1371/journal.ppat.1008343DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7048299PMC
February 2020

A Qualified Success: Discovery of a New Series of ATAD2 Bromodomain Inhibitors with a Novel Binding Mode Using High-Throughput Screening and Hit Qualification.

J Med Chem 2019 08 9;62(16):7506-7525. Epub 2019 Aug 9.

GlaxoSmithKline Tres Cantos , 28760 Tres Cantos , Madrid , Spain.

The bromodomain of ATAD2 has proved to be one of the least-tractable proteins within this target class. Here, we describe the discovery of a new class of inhibitors by high-throughput screening and show how the difficulties encountered in establishing a screening triage capable of finding progressible hits were overcome by data-driven optimization. Despite the prevalence of nonspecific hits and an exceptionally low progressible hit rate (0.001%), our optimized hit qualification strategy employing orthogonal biophysical methods enabled us to identify a single active series. The compounds have a novel ATAD2 binding mode with noncanonical features including the displacement of all conserved water molecules within the active site and a halogen-bonding interaction. In addition to reporting this new series and preliminary structure-activity relationship, we demonstrate the value of diversity screening to complement the knowledge-based approach used in our previous ATAD2 work. We also exemplify tactics that can increase the chance of success when seeking new chemical starting points for novel and less-tractable targets.
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http://dx.doi.org/10.1021/acs.jmedchem.9b00673DOI Listing
August 2019

Bone marrow transplantation generates T cell-dependent control of myeloma in mice.

J Clin Invest 2019 01 19;129(1):106-121. Epub 2018 Nov 19.

QIMR Berghofer Medical Research Institute, Brisbane, Australia.

Transplantation with autologous hematopoietic progenitors remains an important consolidation treatment for patients with multiple myeloma (MM) and is thought to prolong the disease plateau phase by providing intensive cytoreduction. However, transplantation induces inflammation in the context of profound lymphodepletion that may cause hitherto unexpected immunological effects. We developed preclinical models of bone marrow transplantation (BMT) for MM using Vk*MYC myeloma-bearing recipient mice and donor mice that were myeloma naive or myeloma experienced to simulate autologous transplantation. Surprisingly, we demonstrated broad induction of T cell-dependent myeloma control, most efficiently from memory T cells within myeloma-experienced grafts, but also through priming of naive T cells after BMT. CD8+ T cells from mice with controlled myeloma had a distinct T cell receptor (TCR) repertoire and higher clonotype overlap relative to myeloma-free BMT recipients. Furthermore, T cell-dependent myeloma control could be adoptively transferred to secondary recipients and was myeloma cell clone specific. Interestingly, donor-derived IL-17A acted directly on myeloma cells expressing the IL-17 receptor to induce a transcriptional landscape that promoted tumor growth and immune escape. Conversely, donor IFN-γ secretion and signaling were critical to protective immunity and were profoundly augmented by CD137 agonists. These data provide new insights into the mechanisms of action of transplantation in myeloma and provide rational approaches to improving clinical outcomes.
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http://dx.doi.org/10.1172/JCI98888DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6307976PMC
January 2019

Eomesodermin promotes the development of type 1 regulatory T (T1) cells.

Sci Immunol 2017 Apr;2(10)

QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia.

Type 1 regulatory T (T1) cells are Foxp3 interleukin-10 (IL-10)-producing CD4 T cells with potent immunosuppressive properties, but their requirements for lineage development have remained elusive. We show that T1 cells constitute the most abundant regulatory population after allogeneic bone marrow transplantation (BMT), express the transcription factor Eomesodermin (Eomes), and are critical for the prevention of graft-versus-host disease. We demonstrate that Eomes is required for T1 cell differentiation, during which it acts in concert with the transcription factor B lymphocyte-induced maturation protein-1 (Blimp-1) by transcriptionally activating IL-10 expression and repressing differentiation into other T helper cell lineages. We further show that Eomes induction in T1 cells requires T-bet and donor macrophage-derived IL-27. Thus, we define the cellular and transcriptional control of T1 cell differentiation during BMT, opening new avenues to therapeutic manipulation.
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http://dx.doi.org/10.1126/sciimmunol.aah7152DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5714294PMC
April 2017

Acute graft-versus-host disease is regulated by an IL-17-sensitive microbiome.

Blood 2017 04 30;129(15):2172-2185. Epub 2017 Jan 30.

QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.

Donor T-cell-derived interleukin-17A (IL-17A) can mediate late immunopathology in graft-versus-host disease (GVHD), however protective roles remain unclear. Using multiple cytokine and cytokine receptor subunit knockout mice, we demonstrate that stem cell transplant recipients lacking the ability to generate or signal IL-17 develop intestinal hyper-acute GVHD. This protective effect is restricted to the molecular interaction of IL-17A and/or IL-17F with the IL-17 receptor A/C (IL-17RA/C). The protection from GVHD afforded by IL-17A required secretion from, and signaling in, both hematopoietic and nonhematopoietic host tissue. Given the intestinal-specificity of the disease in these animals, we cohoused wild-type (WT) with IL-17RA and IL-17RC-deficient mice, which dramatically enhanced the susceptibility of WT mice to acute GVHD. Furthermore, the gut microbiome of WT mice shifted toward that of the IL-17RA/C mice during cohousing prior to transplant, confirming that an IL-17-sensitive gut microbiota controls susceptibility to acute GVHD. Finally, induced IL-17A depletion peritransplant also enhanced acute GVHD, consistent with an additional protective role for this cytokine independent of effects on dysbiosis.
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http://dx.doi.org/10.1182/blood-2016-08-732628DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5391622PMC
April 2017

GVHD prevents NK-cell-dependent leukemia and virus-specific innate immunity.

Blood 2017 02 7;129(5):630-642. Epub 2016 Dec 7.

Bone Marrow Transplantation Laboratory, Immunology Department, Queensland Institute of Medical Research (QIMR) Berghofer Medical Research Institute, Brisbane, QLD, Australia.

Allogeneic bone marrow transplantation (allo-BMT) is a curative therapy for hematological malignancies, but is associated with significant complications, principally graft-versus-host disease (GVHD) and opportunistic infections. Natural killer (NK) cells mediate important innate immunity that provides a temporal bridge until the reconstruction of adaptive immunity. Here, we show that the development of GVHD after allo-BMT prevented NK-cell reconstitution, particularly within the maturing M1 and M2 NK-cell subsets in association with exaggerated activation, apoptosis, and autophagy. Donor T cells were critical in this process by limiting the availability of interleukin 15 (IL-15), and administration of IL-15/IL-15Rα or immune suppression with rapamycin could restore NK-cell reconstitution. Importantly, the NK-cell defect induced by GVHD resulted in the failure of NK-cell-dependent in vivo cytotoxicity and graft-versus-leukemia effects. Control of cytomegalovirus infection after allo-BMT was also impaired during GVHD. Thus, during GVHD, donor T cells compete with NK cells for IL-15 thereby inducing profound defects in NK-cell reconstitution that compromise both leukemia and pathogen-specific immunity.
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http://dx.doi.org/10.1182/blood-2016-08-734020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5290987PMC
February 2017

Donor colonic CD103+ dendritic cells determine the severity of acute graft-versus-host disease.

J Exp Med 2015 Jul 13;212(8):1303-21. Epub 2015 Jul 13.

QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia The Royal Brisbane and Women's Hospital, Brisbane, Queensland 4029, Australia

The primacy of the gastrointestinal (GI) tract in dictating the outcome of graft-versus-host disease (GVHD) is broadly accepted; however, the mechanisms controlling this effect are poorly understood. Here, we demonstrate that GVHD markedly enhances alloantigen presentation within the mesenteric lymph nodes (mLNs), mediated by donor CD103(+)CD11b(-) dendritic cells (DCs) that migrate from the colon under the influence of CCR7. Expansion and differentiation of donor T cells specifically within the mLNs is driven by profound levels of alloantigen, IL-12, and IL-6 promoted by Toll-like receptor (TLR) and receptor for advanced glycation end products (RAGE) signals. Critically, alloantigen presentation in the mLNs imprints gut-homing integrin signatures on donor T cells, leading to their emigration into the GI tract where they mediate fulminant disease. These data identify a critical, anatomically distinct, donor DC subset that amplifies GVHD. We thus highlight multiple therapeutic targets and the ability of GVHD, once initiated by recipient antigen-presenting cells, to generate a profound, localized, and lethal feed-forward cascade of donor DC-mediated indirect alloantigen presentation and cytokine secretion within the GI tract.
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http://dx.doi.org/10.1084/jem.20150329DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4516799PMC
July 2015

Fragment-Based Discovery of Low-Micromolar ATAD2 Bromodomain Inhibitors.

J Med Chem 2015 Jul 9;58(14):5649-73. Epub 2015 Jul 9.

∥Drug Metabolism and Pharmacokinetics (DMPK), GlaxoSmithKline, Park Road, Ware, Hertfordshire SG12 0DP, United Kingdom.

Overexpression of ATAD2 (ATPase family, AAA domain containing 2) has been linked to disease severity and progression in a wide range of cancers, and is implicated in the regulation of several drivers of cancer growth. Little is known of the dependence of these effects upon the ATAD2 bromodomain, which has been categorized as among the least tractable of its class. The absence of any potent, selective inhibitors limits clear understanding of the therapeutic potential of the bromodomain. Here, we describe the discovery of a hit from a fragment-based targeted array. Optimization of this produced the first known micromolar inhibitors of the ATAD2 bromodomain.
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http://dx.doi.org/10.1021/acs.jmedchem.5b00772DOI Listing
July 2015

Inhibition of PAD4 activity is sufficient to disrupt mouse and human NET formation.

Nat Chem Biol 2015 Mar 26;11(3):189-91. Epub 2015 Jan 26.

1] Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts, USA. [2] Division of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts, USA. [3] Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.

PAD4 has been strongly implicated in the pathogenesis of autoimmune, cardiovascular and oncological diseases through clinical genetics and gene disruption in mice. New selective PAD4 inhibitors binding a calcium-deficient form of the PAD4 enzyme have validated the critical enzymatic role of human and mouse PAD4 in both histone citrullination and neutrophil extracellular trap formation for, to our knowledge, the first time. The therapeutic potential of PAD4 inhibitors can now be explored.
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http://dx.doi.org/10.1038/nchembio.1735DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4397581PMC
March 2015

Spectral-domain optical coherence tomography measures of outer segment layer progression in patients with X-linked retinitis pigmentosa.

JAMA Ophthalmol 2013 Sep;131(9):1143-50

Retina Foundation of the Southwest, Dallas, Texas2Department of Ophthalmology, The University of Texas Southwestern Medical Center, Dallas, Texas.

Importance: Determining the annual rate of change in the width of the inner segment ellipsoid zone (EZ; ie, inner/outer segment border) in the context of short-term variability should allow us to better understand the value of this measure for future treatment trials in X-linked retinitis pigmentosa (XLRP).

Objectives: To identify the width of the central region showing an EZ and to determine the short-term repeat variability and the annual rate of change in the width of the EZ from spectral-domain optical coherence tomography (SD-OCT) measures in RP.

Design: Patients with recessive or simplex RP (age range, 8-65 years; mean age, 40.5 years) underwent scanning twice on the same day to evaluate test-retest variability. Patients with XLRP (age range, 8-27 years; mean age, 15.2 years) from a larger group participating in an ongoing double-blind treatment trial (docosahexaenoic acid vs placebo; clinicaltrials.gov NCT00100230) underwent spectral-domain optical coherence tomography line scanning across the horizontal meridian at 3 yearly intervals.

Setting: Research center specializing in medical retina.

Participants: Forty-eight patients with RP, including 20 with recessive or simplex RP and 28 with XLRP, and 23 healthy control subjects.

Main Outcome And Measure: Widths of the EZ calculated and compared among the 3 annual visits.

Results: Test-retest differences were normally distributed, and the magnitude of the difference was independent of mean EZ width. The mean (SD) for test-retest differences in EZ width was 0.08° (0.22°) (range, -0.30° to 0.60°). Thus, 95% of all test-retest differences fall within ± 0.43° (124 μm). Of the 28 patients with XLRP, 27 showed a significant decrease in EZ width after 2 years. Patients with XLRP showed a mean annual decrease in EZ width of 0.86° (248 μm, or 7%).

Conclusions And Relevance: The mean rate of decline in EZ width (7%) translates into a mean rate of change of 13% for the equivalent area of functioning retina. This rate of change is consistent with that reported for visual fields and full-field electroretinograms. Unlike visual fields and electroretinograms, however, the repeat variability is less than the annual rate of change. These results support the validity of EZ width as an outcome measure in prospective clinical trials in RP.
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http://dx.doi.org/10.1001/jamaophthalmol.2013.4160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4111937PMC
September 2013

Normative reference ranges for the retinal nerve fiber layer, macula, and retinal layer thicknesses in children.

Am J Ophthalmol 2013 Feb 3;155(2):354-360.e1. Epub 2012 Nov 3.

Retina Foundation of the Southwest, Dallas, Texas 75231-0920, USA.

Purpose: To establish a normative database of peripapillary retinal nerve fiber layer (RNFL) thickness, macular thickness, and retinal layer thickness in healthy North American children, using spectral-domain optical coherence tomography (SD OCT).

Design: Prospective cross-sectional study.

Methods: This institutional study enrolled 83 healthy children (aged 5-15 years) as volunteer research subjects at the Retina Foundation of the Southwest (Dallas, Texas); all had normal visual acuity. Imaging was accomplished with the Spectralis SD OCT. Peripapillary RNFL thickness and macular thickness were assessed for 1 eye of each child using the Heidelberg Spectralis SD OCT software. Thicknesses of individual retinal layers and layer combinations were assessed using custom software to segment the line scans obtained with the Spectralis SD OCT.

Results: Average global peripapillary RNFL thickness was 107.6 ± 1.2 μm and average central subfield macular thickness was 271.2 ± 2.0 μm. Peripapillary RNFL thickness was thicker than has been reported in adults, particularly the superior and inferior sectors, and central subfield macular thickness was significantly correlated with age. While the thickness of most retinal layers was comparable with those of adults, the outer segment layer was 36% thinner in children than in adults.

Conclusions: SD OCT can be used to assess peripapillary RNFL thickness, macular thickness, and retinal layer thickness in children as young as 5 years. Pediatric means and normative reference ranges are provided for each measurement. The values presented herein can be used as a standard with which to compare those of children suspected of having retinal or optic nerve abnormalities.
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http://dx.doi.org/10.1016/j.ajo.2012.08.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3545013PMC
February 2013

Rod sensitivity, cone sensitivity, and photoreceptor layer thickness in retinal degenerative diseases.

Invest Ophthalmol Vis Sci 2011 Sep 9;52(10):7141-7. Epub 2011 Sep 9.

Retina Foundation of Southwest, 9900 N. Central Expressway, Suite 400, Dallas, TX 75231, USA.

Purpose: To evaluate the effects of selective rod and/or cone loss on frequency-domain optical coherence tomography (fdOCT) measures of photoreceptor structure in patients with retinal degenerative diseases.

Methods: Six patients with cone dystrophy (CD) and eight patients with retinitis pigmentosa (RP) were recruited from the Southwest Eye Registry on the basis of diagnosis and ERG findings. fdOCT horizontal line scans were segmented to obtain the thicknesses of the outer segments plus RPE (OS+) and the outer nuclear layer (ONL). The normalized product ONL*OS was obtained after dividing by mean ONL*OS values of 23 normal individuals. Visual field sensitivity profiles were obtained with a modified retinal perimeter, from the horizontal midline with short- and long-wave stimuli under dark- and light-adapted conditions.

Results: Patients with CD and normal rod-mediated sensitivity, but decreased cone-mediated sensitivity, showed normal ONL*OS outside the fovea. The total receptor layer was thinned in the fovea, consistent with loss in cone nuclei and Henle's fiber layer. Patients with RP and sensitivity in the dark that was mediated by cones showed ONL*OS thickness that was linearly related to cone sensitivity. ONL*OS thickness was linearly related to rod sensitivity in regions with greater loss of cone than rod sensitivity.

Conclusions: Both rods and cones can support an intact IS/OS junction and normal photoreceptor thickness measures. The product of ONL and OS thicknesses is proportional to the sensitivity mediated by the less abnormal type of photoreceptor.
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http://dx.doi.org/10.1167/iovs.11-7509DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3207717PMC
September 2011