Digital Commons Network^™

Humoral Immune Responses Mediate The Development Of A Restrictive Phenotype Of Chronic Lung Allograft Dysfunction, Keizo Misumi, David S Wheeler, Yoshiro Aoki, Michael P Combs, Russell R Braeuer, Ryuji Higashikubo, Wenjun Li, Daniel Kreisel, Ragini Vittal, Jeffrey Myers, Amir Lagstein, Natalie M Walker, Carol F Farver, Vibha N Lama

Open Access Publications

Understanding the distinct pathogenic mechanisms that culminate in allograft fibrosis and chronic graft failure is key in improving outcomes after solid organ transplantation. Here, we describe an F1 → parent orthotopic lung transplant model of restrictive allograft syndrome (RAS), a particularly fulminant form of chronic lung allograft dysfunction (CLAD), and identify a requisite pathogenic role for humoral immune responses in development of RAS. B6D2F1/J (H2-b/d) donor lungs transplanted into the parent C57BL/6J (H2-b) recipients demonstrated a spectrum of histopathologic changes, ranging from lymphocytic infiltration, fibrinous exudates, and endothelialitis to peribronchial and pleuroparenchymal fibrosis, similar to those noted in the human …

Altered Capicua Expression Drives Regional Purkinje Neuron Vulnerability Through Ion Channel Gene Dysregulation In Spinocerebellar Ataxia Type 1, Ravi Chopra, David D Bushart, John P Cooper, Dhananjay Yellajoshyula, Logan M Morrison, Haoran Huang, Hillary P Handler, Luke J Man, Warunee Dansithong, Daniel R Scoles, Stefan M Pulst, Harry T Orr, Vikram G Shakkottai

2020-Current year OA Pubs

Selective neuronal vulnerability in neurodegenerative disease is poorly understood. Using the ATXN1[82Q] model of spinocerebellar ataxia type 1 (SCA1), we explored the hypothesis that regional differences in Purkinje neuron degeneration could provide novel insights into selective vulnerability. ATXN1[82Q] Purkinje neurons from the anterior cerebellum were found to degenerate earlier than those from the nodular zone, and this early degeneration was associated with selective dysregulation of ion channel transcripts and altered Purkinje neuron spiking. Efforts to understand the basis for selective dysregulation of channel transcripts revealed modestly increased expression of the ATXN1 co-repressor Capicua (Cic) in anterior cerebellar Purkinje neurons. Importantly, …

Macrophage-Associated Lipin-1 Promotes Β-Oxidation In Response To Proresolving Stimuli, Robert M Schilke, Cassidy M R Blackburn, Shashanka Rao, David M Krzywanski, Brian N Finck, Matthew D Woolard

2020-Current year OA Pubs

Macrophages reprogram their metabolism to promote appropriate responses. Proresolving macrophages primarily use fatty acid oxidation as an energy source. Metabolites generated during the catabolism of fatty acids aid in the resolution of inflammation and tissue repair, but the regulatory mechanisms that control lipid metabolism in macrophages are not fully elucidated. Lipin-1, a phosphatidic acid phosphatase that has transcriptional coregulator activity, regulates lipid metabolism in a variety of cells. In this current study, we show that lipin-1 is required for increased oxidative phosphorylation in IL-4 stimulated mouse (

Trem2 Activation On Microglia Promotes Myelin Debris Clearance And Remyelination In A Model Of Multiple Sclerosis, Francesca Cignarella, Fabia Filipello, Bryan Bollman, Claudia Cantoni, Alberto Locca, Robert Mikesell, Melissa Manis, Adiljan Ibrahim, Li Deng, Bruno A Benitez, Carlos Cruchaga, Danilo Licastro, Kathie Mihindukulasuriya, Oscar Harari, Michael Buckland, David M Holtzman, Arnon Rosenthal, Tina Schwabe, Ilaria Tassi, Laura Piccio

2020-Current year OA Pubs

Multiple sclerosis (MS) is an inflammatory, demyelinating, and neurodegenerative disease of the central nervous system (CNS) triggered by autoimmune mechanisms. Microglia are critical for the clearance of myelin debris in areas of demyelination, a key step to allow remyelination. TREM2 is expressed by microglia and promotes microglial survival, proliferation, and phagocytic activity. Herein we demonstrate that TREM2 was highly expressed on myelin-laden phagocytes in active demyelinating lesions in the CNS of subjects with MS. In gene expression studies, macrophages from subjects with TREM2 genetic deficiency displayed a defect in phagocytic pathways. Treatment with a new TREM2 agonistic antibody promoted the …

Testing The Impact Of A Single Nucleotide Polymorphism In A Plasmodium Berghei Apiap2 Transcription Factor On Experimental Cerebral Malaria In Mice, Munir Akkaya, Abhisheka Bansal, Patrick W Sheehan, Mirna Pena, Clare K Cimperman, Chen Feng Qi, Takele Yazew, Thomas D Otto, Oliver Billker, Louis H Miller, Susan K Pierce

Open Access Publications

Cerebral malaria (CM) is the deadliest form of severe Plasmodium infections. Currently, we have limited understanding of the mechanisms by which Plasmodium parasites induce CM. The mouse model of CM, experimental CM (ECM), induced by infection with the rodent parasite, Plasmodium berghei ANKA (PbANKA) has been extensively used to study the pathophysiology of CM. Recent genomic analyses revealed that the coding regions of PbANKA and the closely related Plasmodium berghei NK65 (PbNK65), that does not cause ECM, differ in only 21 single nucleotide polymorphysims (SNPs). Thus, the SNP-containing genes might contribute to the pathogenesis of ECM. Although the majority of …

Enantiomerically Pure Quinoline-Based Κ-Opioid Receptor Agonists: Chemoenzymatic Synthesis And Pharmacological Evaluation, Benedikt Martin, Dirk Schepmann, Freddy A Bernal, Thomas J Schmidt, Tao Che, Karin Loser, Bernhard Wünsch

2020-Current year OA Pubs

Racemic

Glycan Cross-Feeding Supports Mutualism Between Fusobacterium And The Vaginal Microbiota, Kavita Agarwal, Lloyd S. Robinson, Somya Aggarwal, Lynne R. Foster, Ariel Hernandez-Leyva, Hueylie Lin, Brett A. Tortelli, Valerie P. O'Brien, Liza Miller, Andrew L. Kau, Hilary Reno, Nicole M. Gilbert, Warren G. Lewis, Amanda L. Lewis

Open Access Publications

Women with bacterial vaginosis (BV), an imbalance of the vaginal microbiome, are more likely to be colonized by potential pathogens such as Fusobacterium nucleatum, a bacterium linked with intrauterine infection and preterm birth. However, the conditions and mechanisms supporting pathogen colonization during vaginal dysbiosis remain obscure. We demonstrate that sialidase activity, a diagnostic feature of BV, promoted F. nucleatum foraging and growth on mammalian sialoglycans, a nutrient resource that was otherwise inaccessible because of the lack of endogenous F. nucleatum sialidase. In mice with sialidase-producing vaginal microbiotas, mutant F. nucleatum unable to consume sialic acids was impaired in vaginal colonization. …

A Cross-Reactive Antibody Protects Against Ross River Virus Musculoskeletal Disease Despite Rapid Neutralization Escape In Mice, Julie M. Fox, Ling Huang, Stephen Tahan, Laura A. Powell, James E. Crowe, David Wang, Michael S. Diamond

Open Access Publications

Arthritogenic alphaviruses cause debilitating musculoskeletal disease and historically have circulated in distinct regions. With the global spread of chikungunya virus (CHIKV), there now is more geographic overlap, which could result in heterologous immunity affecting natural infection or vaccination. Here, we evaluated the capacity of a cross-reactive anti-CHIKV monoclonal antibody (CHK-265) to protect against disease caused by the distantly related alphavirus, Ross River virus (RRV). Although CHK-265 only moderately neutralizes RRV infection in cell culture, it limited clinical disease in mice independently of Fc effector function activity. Despite this protective phenotype, RRV escaped from CHK-265 neutralization in vivo, with resistant variants …

Radiation Causes Tissue Damage By Dysregulating Inflammasome-Gasdermin D Signaling In Both Host And Transplanted Cells, Jianqiu Xiao, Chun Wang, Juo-Chin Yao, Yael Alippe, Tong Yang, Dustin Kress, Kai Sun, Kourtney L. Kostecki, Joseph B. Monahan, Deborah J. Veis, Yousef Abu-Amer, Daniel C. Link, Gabriel Mbalaviele

Open Access Publications

Radiotherapy is a commonly used conditioning regimen for bone marrow transplantation (BMT). Cytotoxicity limits the use of this life-saving therapy, but the underlying mechanisms remain poorly defined. Here, we use the syngeneic mouse BMT model to test the hypothesis that lethal radiation damages tissues, thereby unleashing signals that indiscriminately activate the inflammasome pathways in host and transplanted cells. We find that a clinically relevant high dose of radiation causes severe damage to bones and the spleen through mechanisms involving the NLRP3 and AIM2 inflammasomes but not the NLRC4 inflammasome. Downstream, we demonstrate that gasdermin D (GSDMD), the common effector of …

Duodenal Microbiota In Stunted Undernourished Children With Enteropathy, Robert Y Chen, Vanderlene L Kung, Matthew C Hibberd, Janaki Guruge, Blanda Di Luccia, Kazi Ahsan, Elizabeth Kennedy, Jesus Santiago-Borges, Michael J Barratt, Jeffrey I Gordon, Et Al

Open Access Publications

BACKGROUND: Environmental enteric dysfunction (EED) is an enigmatic disorder of the small intestine that is postulated to play a role in childhood undernutrition, a pressing global health problem. Defining the incidence of this disorder, its pathophysiological features, and its contribution to impaired linear and ponderal growth has been hampered by the difficulty in directly sampling the small intestinal mucosa and microbial community (microbiota).

METHODS: In this study, among 110 young children (mean age, 18 months) with linear growth stunting who were living in an urban slum in Dhaka, Bangladesh, and had not benefited from a nutritional intervention, we performed endoscopy …

Preterm Intraventricular Hemorrhage In Vitro: Modeling The Cytopathology Of The Ventricular Zone, Leandro Castaneyra-Ruiz, James P Mcallister, Diego M Morales, Steven L Brody, Albert M Isaacs, David D Limbrick

Open Access Publications

BACKGROUND: Severe intraventricular hemorrhage (IVH) is one of the most devastating neurological complications in preterm infants, with the majority suffering long-term neurological morbidity and up to 50% developing post-hemorrhagic hydrocephalus (PHH). Despite the importance of this disease, its cytopathological mechanisms are not well known. An in vitro model of IVH is required to investigate the effects of blood and its components on the developing ventricular zone (VZ) and its stem cell niche. To address this need, we developed a protocol from our accepted in vitro model to mimic the cytopathological conditions of IVH in the preterm infant.

METHODS: Maturing neuroepithelial …

Modulation Of Extracellular Isg15 Signaling By Pathogens And Viral Effector Proteins, Caleb D Swaim, Larissa A Canadeo, Kristen J Monte, Swati Khanna, Deborah J Lenschow, Jon M Huibregtse

Open Access Publications

ISG15 is a ubiquitin-like modifier that also functions extracellularly, signaling through the LFA-1 integrin to promote interferon (IFN)-γ release from natural killer (NK) and T cells. The signals that lead to the production of extracellular ISG15 and the relationship between its two core functions remain unclear. We show that both epithelial cells and lymphocytes can secrete ISG15, which then signals in either an autocrine or paracrine manner to LFA-1-expressing cells. Microbial pathogens and Toll-like receptor (TLR) agonists result in both IFN-β-dependent and -independent secretion of ISG15, and residues required for ISG15 secretion are mapped. Intracellular ISGylation inhibits secretion, and viral …

Multidimensional Imaging Of Liver Injury Repair In Mice Reveals Fundamental Role Of The Ductular Reaction, Kenji Kamimoto, Yasuhiro Nakano, Kota Kaneko, Atsushi Miyajima, Tohru Itoh

Open Access Publications

Upon severe and/or chronic liver injury, ectopic emergence and expansion of atypical biliary epithelial-like cells in the liver parenchyma, known as the ductular reaction, is typically induced and implicated in organ regeneration. Although this phenomenon has long been postulated to represent activation of facultative liver stem/progenitor cells that give rise to new hepatocytes, recent lineage-tracing analyses have challenged this notion, thereby leaving the pro-regenerative role of the ductular reaction enigmatic. Here, we show that the expanded and remodelled intrahepatic biliary epithelia in the ductular reaction constituted functional and complementary bile-excreting conduit systems in injured parenchyma where hepatocyte bile canalicular networks …

Tfeb Is A Master Regulator Of Tumor-Associated Macrophages In Breast Cancer, Yong Li, Johnie Hodge, Qing Liu, Junfeng Wang, Yuzhen Wang, Trent D Evans, Diego Altomare, Yongzhong Yao, E. Angela Murphy, Babak Razani, Daping Fan

2020-Current year OA Pubs

BACKGROUND: Tumor-associated macrophages (TAMs) play key roles in the development of many malignant solid tumors including breast cancer. They are educated in the tumor microenvironment (TME) to promote tumor growth, metastasis, and therapy resistance. However, the phenotype of TAMs is elusive and how to regulate them for therapeutic purpose remains unclear; therefore, TAM-targeting therapies have not yet achieved clinical success. The purposes of this study were to examine the role of transcription factor EB (TFEB) in regulating TAM gene expression and function and to determine if TFEB activation can halt breast tumor development.

METHODS: Microarrays were used to analyze the …

Cd300lf Is The Primary Physiologic Receptor Of Murine Norovirus But Not Human Norovirus, Vincent R. Graziano, Forrest C. Walker, Elizabeth A. Kennedy, Ebrahim Hassan, Arthur S. Kim, Megan T. Baldridge, Et Al.

Open Access Publications

Murine norovirus (MNoV) is an important model of human norovirus (HNoV) and mucosal virus infection more broadly. Viral receptor utilization is a major determinant of cell tropism, host range, and pathogenesis. The bona fide receptor for HNoV is unknown. Recently, we identified CD300lf as a proteinaceous receptor for MNoV. Interestingly, its paralogue CD300ld was also sufficient for MNoV infection in vitro. Here we explored whether CD300lf is the sole physiologic receptor in vivo and whether HNoV can use a CD300 ortholog as an entry receptor. We report that both CD300ld and CD300lf are sufficient for infection by diverse MNoV strains …

Cooperative Synaptic And Intrinsic Plasticity In A Disynaptic Limbic Circuit Drive Stress-Induced Anhedonia And Passive Coping In Mice, Marco Pignatelli, Hugo A Tejeda, Et Al

Open Access Publications

Stress promotes negative affective states, which include anhedonia and passive coping. While these features are in part mediated by neuroadaptations in brain reward circuitry, a comprehensive framework of how stress-induced negative affect may be encoded within key nodes of this circuit is lacking. Here, we show in a mouse model for stress-induced anhedonia and passive coping that these phenomena are associated with increased synaptic strength of ventral hippocampus (VH) excitatory synapses onto D1 medium spiny neurons (D1-MSNs) in the nucleus accumbens medial shell (NAcmSh), and with lateral hypothalamus (LH)-projecting D1-MSN hyperexcitability mediated by decreased inwardly rectifying potassium channel (IRK) function. …

Myd88-Dependent Influx Of Monocytes And Neutrophils Impairs Lymph Node B Cell Responses To Chikungunya Virus Infection Via Irf5, Nos2 And Nox2, Mary K. Mccarthy, Glennys V. Reynoso, Emma S. Winkler, Matthias Mack, Michael S. Diamond, Heather D. Hickman, Thomas E. Morrison

Open Access Publications

Humoral immune responses initiate in the lymph node draining the site of viral infection (dLN). Some viruses subvert LN B cell activation; however, our knowledge of viral hindrance of B cell responses of important human pathogens is lacking. Here, we define mechanisms whereby chikungunya virus (CHIKV), a mosquito-transmitted RNA virus that causes outbreaks of acute and chronic arthritis in humans, hinders dLN antiviral B cell responses. Infection of WT mice with pathogenic, but not acutely cleared CHIKV, induced MyD88-dependent recruitment of monocytes and neutrophils to the dLN. Blocking this influx improved lymphocyte accumulation, dLN organization, and CHIKV-specific B cell responses. …

Regulatory T Cells Developing Peri-Weaning Are Continually Required To Restrain Th2 Systemic Responses Later In Life, Kathryn A. Knoop, Keely G Mcdonald, Chyi-Song Hsieh, Phillip I Tarr, Rodney D Newberry

Open Access Publications

Atopic disorders including allergic rhinitis, asthma, food allergy, and dermatitis, are increasingly prevalent in Western societies. These disorders are largely characterized by T helper type 2 (Th2) immune responses to environmental triggers, particularly inhaled and dietary allergens. Exposure to such stimuli during early childhood reduces the frequency of allergies in at-risk children. These allergic responses can be restrained by regulatory T cells (Tregs), particularly Tregs arising in the gut. The unique attributes of how early life exposure to diet and microbes shape the intestinal Treg population is a topic of significant interest. While imprinting during early life promotes the development …

Cd4 Inhibits Helper T Cell Activation At Lower Affinity Threshold For Full-Length T Cell Receptors Than Single Chain Signaling Constructs, Deborah K Johnson, Wyatt Magoffin, Sheldon J Myers, Jordan G Finnell, John C Hancock, Taylor S Orton, Stephen P Persaud, Kenneth A Christensen, K Scott Weber

Open Access Publications

CD4

Canonical Signaling By Tgf Family Members In Mesenchymal Stromal Cells Is Dispensable For Hematopoietic Niche Maintenance Under Basal And Stress Conditions, Joseph Ryan Krambs, Grazia Abou Ezzi, Juo-Chin Yao, Daniel C. Link

Open Access Publications

Mesenchymal stromal cells are an important component of the bone marrow hematopoietic niche. Prior studies showed that signaling from members of the transforming growth factor (TGF) superfamily in mesenchymal stromal cells is required for normal niche development. Here, we assessed the impact of TGF family signaling on niche maintenance and stress responses by deleting Smad4 in mesenchymal stromal cells at birth, thereby abrogating canonical TGF signaling. No alteration in the number or spatial organization of CXCL12-abundant reticular (CAR) cells, osteoblasts, or adipocytes was observed in Osx-Cre, Smad4fl/fl mice, and expression of key niche factors was normal. Basal hematopoiesis and stress …