Genetics and Genomics Commons^™

Post Operative Fungal Endopthalmitis Due To Geotrichum Candidum, Thein Myint, Matthew J. Dykhuizen, Carolyn H. Mcdonald, Julie A. Ribes

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Geotrichum species have been rarely reported as the cause of sepsis, disseminated infection in immunosuppressed patients. The patient we describe developed indolent endophthalmitis four months after her routine right eye cataract surgery. The intraoperative sample from right vitreous fluid grew Geotrichum candidum. The patient underwent vitrectomy, artificial lens explantation and intravitreal injection of amphotericin B followed by oral voriconazole. Despite these interventions, she underwent enucleation. This is the first published case of Geotrichum candidum endophthalmitis.

Tuberculosis And Cardiovascular Disease: Linking The Epidemics, Moises A. Huaman, David Henson, Eduardo Ticona, Timothy R. Sterling, Beth A. Garvy

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The burden of tuberculosis and cardiovascular disease (CVD) is enormous worldwide. CVD rates are rapidly increasing in low- and middle-income countries. Public health programs have been challenged with the overlapping tuberculosis and CVD epidemics. Monocyte/macrophages, lymphocytes and cytokines involved in cellular mediated immune responses against Mycobacterium tuberculosis are also main drivers of atherogenesis, suggesting a potential pathogenic role of tuberculosis in CVD via mechanisms that have been described for other pathogens that establish chronic infection and latency. Studies have shown a pro-atherogenic effect of antibody-mediated responses against mycobacterial heat shock protein-65 through cross reaction with self-antigens in human vessels. Furthermore, …

Borrelia Burgdorferi Reva Significantly Affects Pathogenicity And Host Response In The Mouse Model Of Lyme Disease, Rebecca Byram, Robert A. Gaultney, Angela M. Floden, Christopher Hellekson, Brandee L. Stone, Amy Bowman, Brian Stevenson, Barbara J. B. Johnson, Catherine A. Brissette

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Lyme disease spirochete, Borrelia burgdorferi, expresses RevA and numerous outer surface lipoproteins during mammalian infection. As an adhesin that promotes bacterial interaction with fibronectin, RevA is poised to interact with the extracellular matrix of the host. To further define the role(s) of RevA during mammalian infection, we created a mutant that is unable to produce RevA. The mutant was still infectious to mice, although it was significantly less well able to infect cardiac tissues. Complementation of the mutant with a wild-type revA gene restored heart infectivity to wild-type levels. Additionally, revA mutants led to increased evidence of arthritis, …

Application Of Β-Lactamase Reporter Fusions As An Indicator Of Effector Protein Secretion During Infections With The Obligate Intracellular Pathogen Chlamydia Trachomatis , Konrad E. Mueller, Kenneth A. Fields

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Chlamydia spp. utilize multiple secretion systems, including the type III secretion system (T3SS), to deploy host-interactive effector proteins into infected host cells. Elucidation of secreted proteins has traditionally required ectopic expression in a surrogate T3SS followed by immunolocalization of endogenous candidate effectors to confirm secretion by chlamydiae. The ability to transform Chlamydia and achieve stable expression of recombinant gene products has enabled a more direct assessment of secretion. We adapted TEM-1 β-lactamase as a reporter system for assessment of chlamydial protein secretion. We provide evidence that this system facilitates visualization of secretion in the context of infection. Specifically, our findings …

Intracellular Listeria Monocytogenes Comprises A Minimal But Vital Fraction Of The Intestinal Burden Following Foodborne Infection, Grant S. Jones, Kate M. Bussell, Tanya Myers-Morales, Abigail M. Fieldhouse, Elsa N. Bou Ghanem, Sarah E. F. D'Orazio

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Listeria monocytogenes is a highly adaptive bacterium that replicates as a free-living saprophyte in the environment as well as a facultative intracellular pathogen that causes invasive foodborne infections. The intracellular life cycle of L. monocytogenes is considered to be its primary virulence determinant during mammalian infection; however, the proportion of L. monocytogenes that is intracellular in vivo has not been studied extensively. In this report, we demonstrate that the majority of wild-type (strain EGDe) and mouse-adapted (InlA^m-expressing) L. monocytogenes recovered from the mesenteric lymph nodes (MLN) was extracellular within the first few days after foodborne infection. In addition, …

Zbtb20 Is A Sequence-Specific Transcriptional Repressor Of Alpha-Fetoprotein Gene, Hai Zhang, Dongmei Cao, Luting Zhou, Ye Zhang, Xiaoqin Guo, Hui Li, Yuxia Chen, Brett T. Spear, Jia-Wei Wu, Zhifang Xie, Weiping J Zhang

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Alpha-fetoprotein (AFP) represents a classical model system to study developmental gene regulation in mammalian cells. We previously reported that liver ZBTB20 is developmentally regulated and plays a central role in AFP postnatal repression. Here we show that ZBTB20 is a sequence-specific transcriptional repressor of AFP. By ELISA-based DNA-protein binding assay and conventional gel shift assay, we successfully identified a ZBTB20-binding site at -104/-86 of mouse AFP gene, flanked by two HNF1 sites and two C/EBP sites in the proximal promoter. Importantly, mutation of the core sequence in this site fully abolished its binding to ZBTB20 in vitro, as well …

Apparent Role For Borrelia Burgdorferi Luxs During Mammalian Infection, William K. Arnold, Christina R. Savage, Alyssa D. Antonicello, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Lyme disease spirochete, Borrelia burgdorferi, controls protein expression patterns during its tick-mammal infection cycle. Earlier studies demonstrated that B. burgdorferi synthesizes 4,5-dihydroxy-2,3-pentanedione (autoinducer-2 [AI-2]) and responds to AI-2 by measurably changing production of several infection-associated proteins. luxS mutants, which are unable to produce AI-2, exhibit altered production of several proteins. B. burgdorferi cannot utilize the other product of LuxS, homocysteine, indicating that phenotypes of luxS mutants are not due to the absence of that molecule. Although a previous study found that a luxS mutant was capable of infecting mice, a critical caveat to those results is that bacterial …

Zhx2 Enhances The Cytotoxicity Of Chemotherapeutic Drugs In Liver Tumor Cells By Repressing Mdr1 Via Interfering With Nf-Ya, Hongxin Ma, Xuetian Yue, Lifen Gao, Xiaohong Liang, Wenjiang Yan, Zhenyu Zhang, Haixia Shan, Hualin Zhang, Brett T. Spear, Chunhong Ma

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We previously reported the tumor suppressor function of Zinc-fingers and homeoboxes 2 (ZHX2) in hepatocellular carcinoma (HCC). Other studies indicate the association of increased ZHX2 expression with improved response to high dose chemotherapy in multiple myeloma. Here, we aim to test whether increased ZHX2 levels in HCC cells repress multidrug resistance 1(MDR1) expression resulting in increased sensitivity to chemotherapeutic drugs. We showed evidence that increased ZHX2 levels correlated with reduced MDR1 expression and enhanced the cytotoxicity of CDDP and ADM in different HCC cell lines. Consistently, elevated ZHX2 significantly reduced ADM efflux in HepG2 cells and greatly increased the CDDP-mediated …

Early Initiation Of Antiretroviral Therapy Can Functionally Control Productive Hiv-1 Infection In Humanized-Blt Mice, Qingsheng Li, For Yue Tso, Guobin Kang, Wuxun Lu, Yue Li, Wenjin Fan, Zhe Yuan, Christopher J. Destache, Charles Wood

Nebraska Center for Virology: Faculty Publications

Background—Recent reports showed that functional control of HIV-1 infection for a prolonged time is possible by early anti-retroviral therapy (ART); however its underlying mechanism needs to be studied with a suitable animal model. Recently, humanized-BLT (bone marrow, liver and thymus) mouse (hu-BLT) was shown to be an excellent model for studying HIV-1 infection. We thus tested the feasibility of studying functional control of HIV-1 infection using hu-BLT mice.

Methods—Animals in three treatment groups (Rx-6h, Rx-24h, Rx-48h) and untreated group were infected with HIV-1, followed by ART initiation at 6, 24 or 48 hours post-infection and continued daily for two weeks. …

The Role Of Dendritic Cell Subsets And Innate Immunity In The Pathogenesis Of Type 1 Diabetes And Other Autoimmune Diseases, Jeffrey D. Price, Kristin V. Tarbell

Nebraska Center for Virology: Faculty Publications

Dendritic cells (DCs) are key antigen-presenting cells that have an important role in autoimmune pathogenesis. DCs control both steady-state T cell tolerance and activation of pathogenic responses. The balance between these two outcomes depends on several factors, including genetic susceptibility, environmental signals that stimulate varied innate responses, and which DC subset is presenting antigen. Although the specific DC phenotype can diverge depending on the tissue location and context, there are four main subsets identified in both mouse and human: conventional cDC1 and cDC2, plasmacytoid DCs, and monocyte-derived DCs. In this review, we will discuss the role of these subsets in …

Gene Function In Schistosomes: Recent Advances Toward A Cure, Arnon D. Jurburg, Paul J. Brindley

Microbiology, Immunology, and Tropical Medicine Faculty Publications

No abstract provided.

A Nuclear Fraction Of Turnip Crinkle Virus Capsid Protein Is Important For Elicitation Of The Host Resistance Response, Sung-Hwan Kang, Feng Qu, Thomas J. Morris

Nebraska Center for Virology: Faculty Publications

The N-terminal 25 amino acids (AAs) of turnip crinkle virus (TCV) capsid protein (CP) are recognized by the resistance protein HRT to trigger a hypersensitive response (HR) and systemic resistance to TCV infection. This same region of TCV CP also contains a motif that interacts with the transcription factor TIP, as well as a nuclear localization signal (NLS). However, it is not yet known whether nuclear localization of TCV CP is needed for the induction of HRT-mediated HR and resistance. Here we present new evidence suggesting a tight correlation between nuclear inclusions formed by CP and the manifestation of HR. …

A Novel Codon-Optimized Siv Gag-Pol Immunogen For Genebased Vaccination, Catherine M. Crosby, Eric A. Weaver, Reeti Khare, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Simian immunodeficiency virus (SIV) is a robust pathogen used in non-human primates to model HIV vaccines. SIV encodes a number of potential vaccine targets. By far the largest and most conserved protein target in SIV is its gag-pol protein that bears many epitopes to drive multivalent immune T cell responses. While gag-pol is an attractive antigen, it is only translated after a frame shift between gag and pol with the effect that gag and pol are expressed at an approximate 10/1 ratio. The codon bias of native lentiviral genes are also mismatched with the abundance of tRNAs in mammalian cells …

Anti-Cancer Activity Of Withaferin A In B-Cell Lymphoma., M K Mckenna, B W Gachuki, S S Alhakeem, K N Oben, V M Rangnekar, R C Gupta, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Withaferin A (WA), a withanolide from the plant, Ashwagandha (Withania somnifera) used in Ayurvedic medicine, has been found to be valuable in the treatment of several medical ailments. WA has been found to have anticancer activity against various solid tumors, but its effects on hematological malignancies have not been studied in detail. WA strongly inhibited the survival of several human and murine B cell lymphoma cell lines. Additionally, in vivo studies with syngeneic-graft lymphoma cells suggest that WA inhibits the growth of tumor but does not affect other proliferative tissues. We demonstrate that WA inhibits the efficiency of NF-κB nuclear …

Whole-Genome Sequencing Of Kaposi’S Sarcoma-Associated Herpesvirus From Zambian Kaposi’S Sarcoma Biopsy Specimens Reveals Unique Viral Diversity, Landon Olp, Adrien Jeanniard, Clemence Marimo, Charles Wood

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiological agent for Kaposi’s sarcoma (KS). Both KSHV and KS are endemic in sub-Saharan Africa where approximately 84% of global KS cases occur. Nevertheless, whole-genome sequencing of KSHV has only been completed using isolates from Western countries—where KS is not endemic. The lack of whole-genome KSHV sequence data from the most clinically important geographical region, sub-Saharan Africa, represents an important gap since it remains unclear whether genomic diversity has a role on KSHV pathogenesis. We hypothesized that distinct KSHV genotypes might be present in sub-Saharan Africa compared to Western countries. Using a KSHV-targeted enrichment …

Observed And Expected Incidence Of Cervical Cancer In Lusaka And The Southern And Western Provinces Of Zambia, 2007 - 2012, Mulele Kalima, Kennedy Lishimpi, Jane L. Meza, Shinobu Watanabe-Galloway, Susan C. Msadabwe, Catherine K. Mwaba, Aaron L. Shibemba, Lewis Banda, Charles Wood, Robert M. Chamberlain, Amr S. Soliman

Nebraska Center for Virology: Faculty Publications

Objectives—Cervical cancer is increasing but underestimated in developing countries. We calculated the observed and expected incidence of cervical cancer in Lusaka and Southern and Western provinces of Zambia.

Methods/Materials—Data for 2007-2012 was obtained for the 3 provinces. Data included age, residence, year of diagnosis, marital status, occupation, HIV, stage, radiotherapy and chemotherapy. Expected incidence in Southern and Western provinces was calculated based on observed incidence for Lusaka province, adjusting for HIV.

Results—Crude and age-standardized incidence rates (ASR) in Lusaka were 2-4 times higher than incidence in the other 2 provinces. Lusaka had a rate of 54.1/10⁵ and ASR of …

Crf07_Bc Strain Dominates The Hiv-1 Epidemic In Injection Drug Users In Liangshan Prefecture Of Sichuan, China, Lin Li, Daying Wei, Wan-Ling Hsu, Tianyi Li, Tao Gui, Charles Wood, Yongjian Liu, Hanping Li, Zuoyi Bao, Siyang Liu, Xiaolin Wang, Jingyun Li

Nebraska Center for Virology: Faculty Publications

The Liangshan prefecture in Sichuan province is an area in China severely affected by the HIV epidemic, with intravenous drug use (IDU) as the main risk factor. No reports on HIV subtypes prevalent in IDUs in Liangshan prefecture could be found. In this study, we have characterized the genotypes of HIV-1 in the IDU population in Liangshan prefecture and further determined the phylogenetic relationship of the CRF07_BC strains to HIV-1 sequences from the other regions of China, including Xinjiang and Yunnan provinces, to explore the pattern and possible diffusion pathway of HIV-1 in these regions. HIV-1-seropositive drug-naive IDUs identified in …

Characterization Of Cd8+ T Cell Differentiation Following Sivδnef Vaccination By Transcription Factor Expression Profiling, James M. Billingsley, Premeela A. Rajakumar, Michelle A. Connole, Nadine C. Salisch, Sama Adnan, Yury V. Kuzmichev, Henoch S. Hong, R. Keith Reeves, Hyung-Joo Kang, Wenjun Li, Qingsheng Li, Ashley T. Haase, R. Paul Johnson

Nebraska Center for Virology: Faculty Publications

The onset of protective immunity against pathogenic SIV challenge in SIVΔnef-vaccinated macaques is delayed for 15-20 weeks, a process that is related to qualitative changes in CD8⁺ T cell responses induced by SIVΔnef. As a novel approach to characterize cell differentiation following vaccination, we used multi-target qPCR to measure transcription factor expression in naïve and memory subsets of CD8+⁺ T cells, and in SIV-specific CD8⁺ T cells obtained from SIVΔnef-vaccinated or wild type SIVmac239-infected macaques. Unsupervised clustering of expression profiles organized naïve and memory CD8⁺ T cells into groups concordant with cell surface phenotype. Transcription factor …

Escherichia Coli Surface Display Of Single-Chain Antibody Vrc01 Against Hiv-1 Infection, Lin-Xu Wang, Michael Mellon, Dane Bowder, Meghan Quinn, Danielle Shea, Charles Wood, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) transmission and infection occur mainly via the mucosal surfaces. The commensal bacteria residing in these surfaces can potentially be employed as a vehicle for delivering inhibitors to prevent HIV-1 infection. In this study, we have employed a bacteria-based strategy to display a broadly neutralizing antibody VRC01, which could potentially be used to prevent HIV-1 infection. The VRC01 antibody mimics CD4-binding to gp120 and has broadly neutralization activities against HIV-1. We have designed a construct that can express the fusion peptide of the scFv-VRC01 antibody together with the autotransporter β-barrel domain of IgAP gene from …

Evidence For Placental Hpv Infection In Both Hiv Positive And Negative Women, Chrispin Chisanga, Dawn Eggert, Charles D. Mitchell, Charles Wood, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Human papillomaviruses (HPVs) have previously been reported to infect epithelial trophoblast cells of the placenta. To investigate this possibility, 200 placental samples from Zambian women were separated into HIV+ and HIV− groups and tested for HPV by redundant primer PCR, using GP5+/GP6+ and CPI/CPII primer sets. Three HPV genotypes (HPV6, 16 and 90) were detected in placental samples. Whereas, 20 different HPV genotypes were detected in vaginal sampling of the same patients, suggesting that compartment specific sub-populations of HPV may exist. The incidence of HPV16 in placental samples was almost 2-fold greater in HIV+ women compared to HIV− (p = …

The Hippo/Yap Pathway Interacts With Egfr Signaling And Hpv Oncoproteins To Regulate Cervical Cancer Progression, Chunbo He, Dagan Mao, Guohua Hua, Xiangmin Lv, Xingcheng Chen, Peter C. Angeletti, Jixin Dong, Steven W. Remmenga, Kerry J. Rodabaugh, Jin Zhou, Paul F. Lambert, Peixin Yang, John S. Davis, Cheng Wang

Nebraska Center for Virology: Faculty Publications

The Hippo signaling pathway controls organ size and tumorigenesis

through a kinase cascade that inactivates Yes-associated

protein (YAP). Here, we show that YAP plays a central role in

controlling the progression of cervical cancer. Our results suggest

that YAP expression is associated with a poor prognosis for cervical

cancer. TGF-α and amphiregulin (AREG), via EGFR, inhibit the Hippo

signaling pathway and activate YAP to induce cervical cancer cell

proliferation and migration. Activated YAP allows for up-regulation

of TGF-α, AREG, and EGFR, forming a positive signaling loop to

drive cervical cancer cell proliferation. HPV E6 protein, a major

etiological molecule of …

Kaposi’S Sarcoma At The University Teaching Hospital, Lusaka, Zambia In The Antiretroviral Therapy Era, Owen Ngalamika, Veenu Minhas, Charles Wood

Nebraska Center for Virology: Faculty Publications

With great interest, we read the recent publication “Kaposi’s sarcoma in HIV-infected patients in South Africa: Multicohort study in the antiretroviral therapy era” by Bohlius et al. We congratulate the authors for their contribution to this field. In this study the authors observed a decrease in incidence of Kaposi’s sarcoma (KS) in patients treated with anti-retroviral therapy (ART) when compared to patients who are not on ART. These results are encouraging because of the ongoing HIV epidemic in sub-Saharan Africa where KS is still one of the most prevalent cancers. Also, it is a relevant topic to study in …

Activation And Degradation Of Open Reading Frame 45 By The Replication And Transcription Activator Of Kaposi's Sarcoma-Associated Herpesvirus, Ying Wang, Kai Yu, Xiuzhi Pei, Tiancheng Zhang, Yuying Guo, Charles Wood, Jinzhong Wang

Nebraska Center for Virology: Faculty Publications

The open reading frame 45 (ORF45) of the Kaposi's sarcoma-associated herpesvirus (KSHV) is an immediate-early phosphorylated tegument protein critical for viral escape from host immune surveillance. Its expression is upregulated by the viral replication and transcription activator (RTA), a key protein that controls the switch from latency to lytic replication. We report here that ORF45 expression was not only upregulated by RTA, but ORF45 could also be degraded by RTA in a proteasome-dependent manner. The ORF45 was activated by RTA via activation of the ORF45 promoter, and the promoter region from nt 69 271 to nt 69 026 was involved. …

Single-Dose Cpg Immunization Protects Against A Heterosubtypic Challenge And Generates Antigen-Specific Memory T Cells, Alexander J. Vogel, Deborah M. Brown

Nebraska Center for Virology: Faculty Publications

Despite extensive research, influenza A virus (IAV) remains a major cause of morbidity, mortality, and healthcare expenditure. Emerging pandemics from highly pathogenic IAV strains, such as H5N1 and pandemic H1N1, highlight the need for universal, crossprotective vaccines. Current vaccine formulations generate strain-specific neutralizing antibodies primarily against the outer coat proteins, hemagglutinin and neuraminidase. In contrast to these highly mutable proteins, internal proteins of IAV are more conserved and are a favorable target for developing vaccines that induce strong T cell responses in addition to humoral immunity. Here, we found that intranasal administration with a single dose of CpG and inactivated …

Long-Acting Parenteral Combination Antiretroviral Loaded Nano-Drug Delivery System To Treat Chronic Hiv-1 Infection: A Humanized Mouse Model Study, Subhra Mandal, Guobin Kang, Pavan Kumar Prathipati, Wenjin Fan, Qingsheng Li, Christopher J. Destache

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus (HIV) patients are often diagnosed in the chronic stage of HIV/AIDS. Combination antiretroviral therapy (cART) has improved quality of life for HIV-infected patients. Present study describes a novel long-acting parenteral formulation of combination antiretroviral (cARV) loaded nano-drugs for treating chronic HIV-1 (cHIV) in a humanized-BLT (hu-BLT) mice model. The cARV (elvitegravir + tenofovir alafenamide + emtricitabine; EVG + TAF + FTC) drugs (mimicking marketed Genvoy® one-pill for HIV-treatment) were encapsulated in poly (lactic-co-glycolic acid) nanoparticles (NPs). To establish cHIV, hu-BLT mice were intravaginally challenged with HIV-1 and maintained for 15 weeks. Plasma viral load (pVL) was monitored …

Caspase-3 Mediates The Pathogenic Effect Of Yersinia Pestis Yopm In Liver Of C57bl/6 Mice And Contributes To Yopm's Function In Spleen, Zhan Ye, Amanda A. Gorman, Annette M. Uittenbogaard, Tanya Myers-Morales, Alan M. Kaplan, Donald A. Cohen, Susan C. Straley

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The virulence protein YopM of the plague bacterium Yersinia pestis has different dominant effects in liver and spleen. Previous studies focused on spleen, where YopM inhibits accumulation of inflammatory dendritic cells. In the present study we focused on liver, where PMN function may be directly undermined by YopM without changes in inflammatory cell numbers in the initial days of infection, and foci of inflammation are easily identified. Mice were infected with parent and ΔyopM-1 Y. pestis KIM5, and effects of YopM were assessed by immunohistochemistry and determinations of bacterial viable numbers in organs. The bacteria were found …

Cyclic Di-Gmp-Dependent Signaling Pathways In The Pathogenic Firmicute Listeria Monocytogenes, Li-Hong Chen, Volkan K. Köseoğlu, Zehra T. Güvener, Tanya Myers-Morales, Joseph M. Reed, Sarah E. F. D'Orazio, Kurt W. Miller, Mark Gomelsky

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We characterized key components and major targets of the c-di-GMP signaling pathways in the foodborne pathogen Listeria monocytogenes, identified a new c-di-GMP-inducible exopolysaccharide responsible for motility inhibition, cell aggregation, and enhanced tolerance to disinfectants and desiccation, and provided first insights into the role of c-di-GMP signaling in listerial virulence. Genome-wide genetic and biochemical analyses of c-di-GMP signaling pathways revealed that L. monocytogenes has three GGDEF domain proteins, DgcA (Lmo1911), DgcB (Lmo1912) and DgcC (Lmo2174), that possess diguanylate cyclase activity, and three EAL domain proteins, PdeB (Lmo0131), PdeC (Lmo1914) and PdeD (Lmo0111), that possess c-di-GMP phosphodiesterase activity. Deletion of all phosphodiesterase …

Cyclic Di-Gmp-Dependent Signaling Pathways In The Pathogenic Firmicute Listeria Monocytogenes, Li-Hong Chen, Volkan K. Köseoğlu, Zehra T. Güvener, Tanya Myers-Morales, Joseph M. Reed, Sarah E. F. D'Orazio, Kurt W. Miller, Mark Gomelsky

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We characterized key components and major targets of the c-di-GMP signaling pathways in the foodborne pathogen Listeria monocytogenes, identified a new c-di-GMP-inducible exopolysaccharide responsible for motility inhibition, cell aggregation, and enhanced tolerance to disinfectants and desiccation, and provided first insights into the role of c-di-GMP signaling in listerial virulence. Genome-wide genetic and biochemical analyses of c-di-GMP signaling pathways revealed that L. monocytogenes has three GGDEF domain proteins, DgcA (Lmo1911), DgcB (Lmo1912) and DgcC (Lmo2174), that possess diguanylate cyclase activity, and three EAL domain proteins, PdeB (Lmo0131), PdeC (Lmo1914) and PdeD (Lmo0111), that possess c-di-GMP phosphodiesterase activity. Deletion of all …

Imaging Luciferase-Expressing Viruses, Michael A. Barry, Shannon May, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

Optical imaging of luciferage gene expression has become a powerful tool to track cells and viruses in vivo in small animal models. Luciferase imaging has been used to study the location of infection by replication-defective and replication-competent viruses and to track changes in the distribution of viruses in mouse models. This approach has also been used in oncolytic studies as a non-invasive means to monitor the growth and killing of tumor cells modified with luciferase genes. In this chapter, we describe the techniques used for luciferase imaging as have been applied to track replication-defective and replication-competent adenoviruses in mouse and …

Vcam-1/Α4Β1 Integrin Interaction Is Crucial For Prompt Recruitment Of Immune T Cells Into The Brain During The Early Stage Of Reactivation Of Chronic Infection With Toxoplasma Gondii To Prevent Toxoplasmic Encephalitis, Qila Sa, Eri Ochiai, Tomoko Sengoku, Melinda E. Wilson, Morgan Brogli, Stephen Crutcher, Sara A. Michie, Baohui Xu, Laura Payne, Xisheng Wang, Yasuhiro Suzuki

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Reactivation of chronic infection with Toxoplasma gondii can cause life-threatening toxoplasmic encephalitis in immunocompromised individuals. We examined the role of VCAM-1/α4β1 integrin interaction in T cell recruitment to prevent reactivation of the infection in the brain. SCID mice were infected and treated with sulfadiazine to establish a chronic infection. VCAM-1 and ICAM-1 were the endothelial adhesion molecules detected on cerebral vessels of the infected SCID and wild-type animals. Immune T cells from infected wild-type mice were treated with anti-α4 integrin or control antibodies and transferred into infected SCID or nude mice, and the animals received the same antibody every other …