Immunity Commons^™

The Pathological Effects Of Ccr2+ Inflammatory Monocytes Are Amplified By An Ifnar1-Triggered Chemokine Feedback Loop In Highly Pathogenic Influenza Infection, Sue-Jane Lin, Ming Lo, Rei-Lin Kuo, Shin-Ru Shih, David M. Ojcius, Jean Lu, Chien-Kuo Lee, Hui-Chen Chen, Meei Yun Lin, Chuen-Miin Leu, Chia-Ni Lin, Ching-Hwa Tsai

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Background: Highly pathogenic influenza viruses cause high levels of morbidity, including excessive infiltration of leukocytes into the lungs, high viral loads and a cytokine storm. However, the details of how these pathological features unfold in severe influenza infections remain unclear. Accumulation of Gr1 + CD11b + myeloid cells has been observed in highly pathogenic influenza infections but it is not clear how and why they accumulate in the severely inflamed lung. In this study, we selected this cell population as a target to investigate the extreme inflammatory response during severe influenza infection.

Results: We established H1N1 IAV-infected mouse models using …

Characterization Of Severe Fever With Thrombocytopenia Syndrome In Rural Regions Of Zhejiang, China, Lei Zhang, Ling Ye, David M. Ojcius, Xiuyu Lou, Chengwei Wang, Cen Feng, Yi Sun, Zhongfa Wang, Shibo Li, Yanjun Zhang

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Severe fever with thrombocytopenia syndrome virus (SFTSV) infections have recently been found in rural regions of Zhejiang. A severe fever with thrombocytopenia syndrome (SFTS) surveillance and sero-epidemiological investigation was conducted in the districts with outbreaks. During the study period of 2011–2014, a total of 51 SFTSV infection cases were identified and the case fatality rate was 12% (6/51). Ninety two percent of the patients (47/51) were over 50 years of age, and 63% (32/51) of laboratory confirmed cases occurred from May to July. Nine percent (11/120) of the serum samples from local healthy people without symptoms were found to be …

A Cytoplasmic Rna Virus Generates Functional Viral Small Rnas And Regulates Viral Ires Activity In Mammalian Cells, Kuo-Feng Weng, Chuan-Tien Hung, Po-Ting Hsieh, Mei-Ling L. Li, Guang-Wu Chen, Yu-An Kung, Peng-Nien Huang, Rei-Lin Kuo, Li-Lien Chen, Jing-Yi Lin, Robert Yung-Liang Wang, Shu-Jen Chen, Petrus Tang, Jim-Tong Horng, Hsing-I Huang, Jen-Ren Wang, David M. Ojcius, Gary Brewer, Shin-Ru Shih

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The roles of virus-derived small RNAs (vsRNAs) have been studied in plants and insects. However, the generation and function of small RNAs from cytoplasmic RNA viruses in mammalian cells remain unexplored. This study describes four vsRNAs that were detected in enterovirus 71-infected cells using next-generation sequencing and northern blots. Viral infection produced substantial levels (>10⁵ copy numbers per cell) of vsRNA1, one of the four vsRNAs. We also demonstrated that Dicer is involved in vsRNA1 generation in infected cells. vsRNA1 overexpression inhibited viral translation and internal ribosomal entry site (IRES) activity in infected cells. Conversely, blocking vsRNA1 enhanced …

The Microtubule-Associated Protein, Eb1, Links Aim2 Inflammasomes With Autophagy-Dependent Secretion, Li-Jie Wang, Hsin-Yi Huang, Meng-Pin Huang, Willisa Liou, Ya-Ting Chang, Chih-Ching Wu, David M. Ojcius, Yu-Sun Chang

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Inflammasomes are multi-protein complexes that regulate chronic inflammation-associated diseases by inducing interleukin-1 β (IL-1β) secretion. Numerous components involved in inflammasome activation have been identified, but the mechanisms of inflammasome-mediated IL-1β secretion have not yet been fully explored. Here, we demonstrate that end-binding protein 1 (EB1), which is required for activation of AIM2 inflammasome complex, links the AIM2 inflammasome to autophagy-dependent secretion. Imaging studies revealed that AIM2 inflammasomes colocalize with microtubule organizing centers and autophagosomes. Biochemical analyses showed that poly(dA-dT)-activated AIM2 inflammasomes induce autophagy and IL-1β secretion in an LC3-dependent fashion. Furthermore, depletion of EB1 decreases autophagic shedding and intracellular trafficking. …

Antiviral Responses In Mouse Embryonic Stem Cells: Differential Development Of Cellular Mechanisms In Type I Interferon Production And Response, Ruoxing Wang

Dissertations

Embryonic stem cells (ESCs) have been recognized as a promising cell source for regenerative medicine. Intensive research over the past decade has led to the possibility that ESC-derived cells will be used for the treatment of human diseases. However, increasing evidence indicates that ESC-derived cells generated by the current differentiation methods are not fully functional. It is recently recognized that ESC-derived cells lack innate immunity to a wide range of infectious agents and inflammatory cytokines. When used in patients, ESC-derived cells would be placed in wounded sites that are exposed to various pathogens and inflammatory cytokines; therefore, their viability and …

Identification Of Cd24 As A Cancer Stem Cell Marker In Human Nasopharyngeal Carcinoma, Chun-Hung Yang, Hui-Ling Wang, Yi-Sheng Lin, K. P. Shravan Kumar, Hung-Chi Lin, Chih-Jung Chang, Chia-Chen Lu, Tsung-Teng Huang, Jan Martel, David M. Ojcius, Yu-Sun Chang, John Ding-E. Young, Hsin-Chih Lai

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Cancer stem cells (CSCs) represent a unique sub-population of tumor cells with the ability to initiate tumor growth and sustain self-renewal. Although CSC biomarkers have been described for various tumors, only a few markers have been identified for nasopharyngeal carcinoma (NPC). In this study, we show that CD24⁺ cells isolated from human NPC cell lines express stem cell genes (Sox2, Oct4, Nanog, Bmi-1, and Rex-1), and show activation of the Wnt/β-catenin signaling pathway. CD24⁺ cells possess typical CSC characteristics that include enhanced cell proliferation, increased colony and sphere formation, maintenance of cell differentiation potential in prolonged …

The Effect Of Small Molecule 390 On Cxcr4 Receptors, Selam B. Zenebe-Gete '14, Shruti R. Topudurti '14, Shum Andrew, Richard J. Miller

Student Publications & Research

CXCR4 is the chemokine receptor which aids in chemotaxis of stem cells, such as those in the bone marrow or the brain. SDF-1 is the natural ligand for the CXCR4 receptor. Similarities between novel molecule 390 synthesized by the Miller Lab and SDF-1 make this novel small molecule a possible agonist of the CXCR4 receptor. To determine whether 390 is an agonist to the CXCR4 receptor, we transfected cells with CXCR4 and exposed them to no agonist [vehicle control], SDF-1, or varying concentrations of our agonist drug. Next, we took calcium images using the dye fura-2, which indicates changes in …

Modeling The Adaptive Immune Response To Mutation-Generated Antigens, Rory J. Geyer

University Scholar Projects

Somatic mutations may drive tumorigenesis or lead to new, immunogenic epitopes (neoantigens). The immune system is thought to represses neoplastic growths through the recognition of neoantigens presented only by tumor cells. To study mutations as well as the immune response to mutation-generated antigens, we have created a conditional knockin mouse line with a gene encoding, 5’ to 3’, yellow fluorescent protein (YFP), ovalbumin (which is processed to the immunologically recognizable peptide, SIINFEKL), and cyan fluorescent protein (CFP), or, YFP-ovalbumin-CFP. A frame shift mutation has been created at the 5’ end of the ovalbumin gene, hence YFP should always be expressed, …

Modeling The Adaptive Immune Response To Mutation-Generated Antigens, Rory J. Geyer

Honors Scholar Theses

Somatic mutations may drive tumorigenesis or lead to new, immunogenic epitopes (neoantigens). The immune system is thought to represses neoplastic growths through the recognition of neoantigens presented only by tumor cells. To study mutations as well as the immune response to mutation-generated antigens, we have created a conditional knockin mouse line with a gene encoding, 5’ to 3’, yellow fluorescent protein (YFP), ovalbumin (which is processed to the immunologically recognizable peptide, SIINFEKL), and cyan fluorescent protein (CFP), or, YFP-ovalbumin-CFP. A frame shift mutation has been created at the 5’ end of the ovalbumin gene, hence YFP should always be expressed, …

Trail-R1 Is A Negative Regulator Of Pro-Inflammatory Responses And Modulates Long-Term Sequelae Resulting From Chlamydia Trachomatis Infections In Humans, Mufadhal Al-Kuhlani, James Rothchild, Sukumar Pal, Luis M. De La Maza, Sander Ouberg, Servaas A. Morré, Deborah Dean, David M. Ojcius

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The immune system eliminates Chlamydia trachomatis infection through inflammation. However, uncontrolled inflammation can enhance pathology. In mice, TNF-related apoptosis-inducing ligand receptor (TRAIL-R), known for its effects on apoptosis, also regulates inflammation. In humans, the four homologues of TRAIL-R had never been investigated for effects on inflammation. Here, we examined whether TRAIL-R regulates inflammation during chlamydial infection. We examined TRAIL-R1 single nucleotide polymorphisms (SNPs) in an Ecuadorian cohort with and without C. trachomatis infections. There was a highly significant association for the TRAIL+626 homozygous mutant GG for infection vs no infection in this population. To confirm the results observed in the …

Novel And Predominant Pathogen Responsible For The Enterovirus-Associated Encephalitis In Eastern China, Lei Zhang, Jie Yan, David M. Ojcius, Huakun Lv, Ziping Miao, Yin Chen, Yanjun Zhang, Jvying Yan

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Enteroviruses (EV) have been increasingly identified as the causative agent for unknown etiological encephalitis in many parts of the world, but the long period surveillance for enterovirus-associated encephalitis (EAE) was not reported in China. From 2002-2012 in Zhejiang, Coxsackieviruses A9, B1, B2, B3, B4, B5; and echoviruses 3, 4, 6, 9, 14, 25, 30 were detected from the unknown etiological encephalitis cases, with coxsackievirus B4 been identified here for the first time. From 2002-2004 and 2010-2012, echovirus 30 was found to be the periodically predominant serotype for in the EAE. The molecular typing results showed that all the EV isolates …

Membrane Vesicles Nucleate Mineralo-Organic Nanoparticles And Induce Carbonate Apatite Precipitation In Human Body Fluids, Cheng-Yeu Wu, Jan Martel, Wei-Yun Cheng, Chao-Chih He, David M. Ojcius, John Ding-E. Young

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Recent studies indicate that membrane vesicles (MVs) secreted by various cells are associated with human diseases, including arthritis, atherosclerosis, cancer, and chronic kidney disease. The possibility that MVs may induce the formation of mineralo-organic nanoparticles (NPs) and ectopic calcification has not been investigated so far. Here, we isolated MVs ranging in size between 20 and 400 nm from human serum and FBS using ultracentrifugation and sucrose gradient centrifugation. The MV preparations consisted of phospholipid-bound vesicles containing the serum proteins albumin, fetuin-A, and apolipoprotein A1; the mineralization-associated enzyme alkaline phosphatase; and the exosome proteins TNFR1 and CD63. Notably, we observed that …

Identification Of Leptospira Interrogans Phospholipase C As A Novel Virulence Factor Responsible For Intracellular Free Calcium Ion Elevation During Macrophage Death, Jing-Fang Zhao, Hong-Hu Chen, David M. Ojcius, Xin Zhao, Dexter Sun, Yu-Mei Ge, Lin-Li Zheng, Xu'ai Lin, Lan-Juan Li, Jie Yan

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Background: Leptospira-induced macrophage death has been confirmed to play a crucial role in pathogenesis of leptospirosis, a worldwide zoonotic infectious disease. Intracellular free Ca²⁺ concentration ([Ca²⁺]i) elevation induced by infection can cause cell death, but [Ca²⁺]i changes and high [Ca²⁺]i-induced death of macrophages due to infection of Leptospira have not been previously reported.

Methodology/Principal Findings: We first used a Ca²⁺-specific fluorescence probe to confirm that the infection of L. interrogans strain Lai triggered a significant increase of [Ca²⁺]i in mouse J774A.1 or human THP-1 macrophages. Laser confocal microscopic examination …

P2x4 Assembles With P2x7 And Pannexin-1 In Gingival Epithelial Cells And Modulates Reactive Oxygen Species Production And Inflammasome Activation, Shu-Chen Hung, Chul Hee Choi, Najwane Said-Sadier, Larry Johnson, Kalina Rosenova Atanasova, Hanen Sellami, Özlem Yilmaz, David M. Ojcius

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We have previously reported that Porphyromonas gingivalis infection of gingival epithelial cells (GEC) requires an exogenous danger signal such as ATP to activate an inflammasome and caspase-1, thereby inducing secretion of interleukin (IL)-1β. Stimulation with extracellular ATP also stimulates production of reactive oxygen species (ROS) in GEC. However, the mechanism by which ROS is generated in response to ATP, and the role that different purinergic receptors may play in inflammasome activation, is still unclear. In this study, we revealed that the purinergic receptor P2X₄ is assembled with the receptor P2X₇ and its associated pore, pannexin-1. ATP induces ROS …

Hirsutella Sinensis Mycelium Suppresses Interleukin-1b And Interleukin-18 Secretion By Inhibiting Both Canonical And Non-Canonical Inflammasomes, Tsung-Teng Huang, Kowit-Yu Chong, David M. Ojcius, Yi-Hui Wu, Yun-Fei Ko, Cheng-Yeu Wu, Jan Martel, Chia-Chen Lu, Hsin-Chih Lai, John Ding-E. Young

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Cordyceps sinensis is a medicinal mushroom used for centuries in Asian countries as a health supplement and tonic. Hirsutella sinensis—the anamorphic, mycelial form of C. sinensis—possesses similar properties, and is increasingly used as a health supplement. Recently, C. sinensis extracts were shown to inhibit the production of the pro-inflammatory cytokine IL-1β in lipopolysaccharide-treated macrophages. However, the molecular mechanism underlying this process has remained unclear. In addition, whether H. sinensis mycelium (HSM) extracts also inhibit the production of IL-1β has not been investigated. In the present study, the HSM extract suppresses IL-1β and IL-18 secretion, and ATP-induced activation of caspase-1. Notably, …

Tumour Inflammasome-Derived Il-1b Recruits Neutrophils And Improves Local Recurrence-Free Survival In Ebv-Induced Nasopharyngeal Carcinoma, Lih-Chyang Chen, Li-Jie Wang, Nang-Ming Tsang, David M. Ojcius, Chia-Chen Chen, Chun-Nan Ouyang, Chuen Hsueh, Ying Liang, Kai-Ping Chang, Chiu-Chin Chen, Yu-Sun Chang

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Inflammasomes sense infection and cellular damage and are critical for triggering inflammation through IL-1β production. In carcinogenesis, inflammasomes may have contradictory roles through facilitating antitumour immunity and inducing oncogenic factors. Their function in cancer remains poorly characterized. Here we show that the NLRP3, AIM2 and RIG-I inflammasomes are overexpressed in Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC), and expression levels correlate with patient survival. In tumour cells, AIM2 and RIG-I are required for IL-1β induction by EBV genomic DNA and EBV-encoded small RNAs, respectively, while NLRP3 responds to extracellular ATP and reactive oxygen species. Irradiation and chemotherapy can further activate AIM2 …

Reversible Inhibition Of Chlamydia Trachomatis Infection In Epithelial Cells Due To Stimulation Of P2x4 Receptors, Matthew A. Pettengill, Camila Marques-Da-Silva, Maria Luisa Avila, Verissa W. Lam, Ikechukwu Ollawa, Ali Abdul-Sater, Robson Coutinho-Silva, Georg Hacker, David M. Ojcius, Suellen D'Arc Dos Santos Oliveira

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Bacterial infections of the mucosal epithelium are a major cause of human disease. The prolonged presence of microbial pathogens stimulates inflammation of the local tissues, which leads to changes in the molecular composition of the extracellular milieu. A well-characterized molecule that is released to the extracellular milieu by stressed or infected cells is extracellular ATP and its ecto-enzymatic degradation products, which function as signaling molecules through ligation of purinergic receptors. There has been little information, however, on the effects of the extracellular metabolites on bacterial growth in inflamed tissues. Millimolar concentrations of ATP have been previously shown to inhibit irreversibly …

Ivermectin Inhibits Growth Of Chlamydia Trachomatis In Epithelial Cells, Matthew A. Pettengill, Verissa W. Lam, Ikechukwu Ollawa, Camila Marques-Da-Silva, David M. Ojcius

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Ivermectin is currently approved for treatment of both clinical and veterinary infections by nematodes, including Onchocerca cervicalis in horses and Onchocerca volvulus in humans. However, ivermectin has never been shown to be effective against bacterial pathogens. Here we show that ivermectin also inhibits infection of epithelial cells by the bacterial pathogen, Chlamydia trachomatis, at doses that could be envisioned clinically for sexually-transmitted or ocular infections by Chlamydia.

Interactome-Wide Analysis Identifies End-Binding Protein 1 As A Crucial Component For The Speck-Like Particle Formation Of Activated Absence In Melanoma 2 (Aim2) Inflammasomes, Li-Jie Wang, Chia-Wei Hsu, Chiu-Chin Chen, Ying Liang, Lih-Chyang Chen, David M. Ojcius, Ngan-Ming Tsang, Chuen Hsueh, Chih-Ching Wu, Yu-Sun Chang

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Inflammasomes are cytoplasmic receptors that can recognize intracellular pathogens or danger signals and are critical for interleukin 1β production. Although several key components of inflammasome activation have been identified, there has not been a systematic analysis of the protein components found in the stimulated complex. In this study, we used the isobaric tags for relative and absolute quantification approach to systemically analyze the interactomes of the NLRP3, AIM2, and RIG-I inflammasomes in nasopharyngeal carcinoma cells treated with specific stimuli of these interactomes (H2O2, poly (dA:dT), and EBV noncoding RNA, respectively). We identified a number of proteins that appeared to be …

Leptospiral Hemolysins Induce Proinflammatory Cytokines Through Toll-Like Receptor 2-And 4-Mediated Jnk And Nf-Κb Signaling Pathways, Huan Wang, Yifei Hu, David M. Ojcius, X. Frank Yang, Chenglin Zhang, Shibiao Ding, Xu'ai Lin, Jie Yan

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Infection with pathogenic Leptospira species causes serious systemic inflammation in patients. Although a few leptospiral proinflammatory molecules have been identified, Leptospira likely encodes other unidentified strong inflammation stimulators. The pathogenic L. interrogans genome encodes numerous putative hemolysin genes. Since hemolysins from other bacteria can cause inflammatory reactions, we hypothesized that leptospiral hemolysins may function as proinflammatory stimulators that contribute to the strong inflammation associated with Leptospira infection.

The Anti-Tumorigenic Mushroom Agaricus Blazei Murill Enhances Il-1Β Production And Activates The Nlrp3 Inflammasome In Human Macrophages, Tsung-Teng Huang, David M. Ojcius, John Ding-E. Young, Yi-Hui Wu, Yun-Fei Ko, Tsui-Yin Wong, Cheng-Yeu Wu, Chia-Chen Lu, Hsin-Chih Lai

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Agaricus blazei Murill (AbM) has been reported to possess immune activity against tumors and infections through stimulation of mononuclear phagocytes. Recently, AbM extract was shown to induce the production of the pro-inflammatory cytokine, interleukin-1β (IL-1β), in human monocytes. IL-1β is a key pro-inflammatory cytokine produced by activated macrophages and monocytes and its secretion is strictly controlled by the inflammasome. The purpose of this study is to investigate the effect of AbM water extracts on the regulation of IL-1β production and activation of the NLRP3 inflammasome in human THP-1 macrophages. The NLRP3 inflammasome consists of an NLRP3 receptor, an adaptor protein …

Host Pathogen Interactions: Is Arabidopsis Thaliana Remembered By Its Nemesis Pseudomonas Syringae?, Daniel Z. Kreiser

Lawrence University Honors Projects

Plants contain innate immune systems that deter pathogen infection. Pattern recognition receptors bind microbe-associated molecular patterns (MAMPs), triggering immunity. MAMPs are proteins exclusive to pathogens that are typically indispensable for their survival. For this reason, MAMPs cannot be mutated or removed without causing pathogen death. However, this does not necessitate constitutive expression of MAMPs. In this study, the MAMP response of Arabidopsis thaliana was utilized to determine differential detection of MAMPs expressed by Pseudomonas syringe pv. tomato DC3000 when pretreated with A. thaliana. Results demonstrated that more MAMPs are detected when P. syringae had previously encountered A. thaliana, …

Activation Of An Nlrp3 Inflammasome Restricts Mycobacterium Kansasii Infection, Chang-Chieh Chen, Sheng-Hui Tsai, Chia-Chen Lu, Shiau-Ting Hu, Ting-Shu Wu, Tsung-Teng Huang, Najwane Saïd-Sadier, David M. Ojcius, Hsin-Chih Lai

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Mycobacterium kansasii has emerged as an important nontuberculous mycobacterium pathogen, whose incidence and prevalence have been increasing in the last decade. M. kansasii can cause pulmonary tuberculosis clinically and radiographically indistinguishable from that caused by Mycobacterium tuberculosis infection. Unlike the widely-studied M. tuberculosis, little is known about the innate immune response against M. kansasii infection. Although inflammasome activation plays an important role in host defense against bacterial infection, its role against atypical mycobacteria remains poorly understood. In this report, the role of inflammasome activity in THP-1 macrophages against M. kansasii infection was studied. Results indicated that viable, but not heat-killed, …

Development Of A Humanized Hla-A2.1/Dp4 Transgenic Mouse Model And The Use Of This Model To Map Hla-Dp4-Restricted Epitopes Of Hbv Envelope Protein, Zhitao Ru, Wenjun Xiao, Anthony Pajot, Zhihua Kou, Shihui Sun, Benard Maillere, Guangyu Zhao, David M. Ojcius, Yu-Chun Lone, Yusen Zhou

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A new homozygous humanized transgenic mouse strain, HLA-A2.1^+/+HLA-DP4^+/+ hCD4^+/+mCD4^−/−IAβ^−/−β2m^−/− (HLA-A2/DP4), was obtained by crossing the previously characterized HLA-A2^+/+β2m−/− (A2) mouse and our previously created HLA-DP4^+/+ hCD4^+/+mCD4^−/−IAβ^−/− (DP4) mouse. We confirmed that the transgenes (HLA-A2, HLA-DP4, hCD4) inherited from the parental A2 and DP4 mice are functional in the HLA-A2/DP4 mice. After immunizing HLA-A2/DP4 mice with a hepatitis B DNA vaccine, hepatitis B virus-specific antibodies, HLA-A2-restricted and HLA-DP4-restricted responses were observed to be similar to those in naturally infected humans. Therefore, the present …

Extracellular Atp Acts On P2y2 Purinergic Receptors To Facilitate Hiv-1 Infection, Claire Séror, Marie-Therese Melki, Frederic Subra, Syed Qasim Raza, Marlene Bras, Hela Saïdi, Roberta Nardacci, Laurent Voisin, Audrey Paoletti, Frederic Law, Isabelle Martins, Alessandra Amendola, Ali A. Abdul-Sater, Fabiola Ciccosanti, Olivier Delelis, Florence Niedergang, Sylvain Thierry, Najwane Said-Sadier, Christophe Lamaze, Didier Métivier, Jerome Estaquier, Gian Maria Fimia, Laura Falasca, Rita Casetti, Nazanine Modjtahedi, Jean M. Kanellopoulos, Jean-Francois Mouscadet, David M. Ojcius, Mauro Piacentini, Marie-Lise Gougeon, Guido Kroemer, Jean-Luc Perfetini

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Extracellular adenosine triphosphate (ATP) can activate purinergic receptors of the plasma membrane and modulate multiple cellular functions. We report that ATP is released from HIV-1 target cells through pannexin-1 channels upon interaction between the HIV-1 envelope protein and specific target cell receptors. Extracellular ATP then acts on purinergic receptors, including P2Y2, to activate proline-rich tyrosine kinase 2 (Pyk2) kinase and transient plasma membrane depolarization, which in turn stimulate fusion between Env-expressing membranes and membranes containing CD4 plus appropriate chemokine co-receptors. Inhibition of any of the constituents of this cascade (pannexin-1, ATP, P2Y2, and Pyk2) impairs the replication of HIV-1 mutant …

Caspase-1 Dependent Il-1Β Secretion Is Critical For Host Defense In A Mouse Model Of Chlamydia Pneumoniae Lung Infection, Kenichi Shimada, Timothy R. Crother, Justin Karlin, Shuang Chen, Norika Chiba, V. Krishnan Ramanujan, Laurent Vergnes, David M. Ojcius, Moshe Arditi

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Chlamydia pneumoniae (CP) is an important human pathogen that causes atypical pneumonia and is associated with various chronic inflammatory disorders. Caspase-1 is a key component of the ‘inflammasome’, and is required to cleave pro-IL-1β to bioactive IL-1β. Here we demonstrate for the first time a critical requirement for IL-1β in response to CP infection. Caspase-1^−/− mice exhibit delayed cytokine production, defective clearance of pulmonary bacteria and higher mortality in response to CP infection. Alveolar macrophages harbored increased bacterial numbers due to reduced iNOS levels in Caspase-1^−/− mice. Pharmacological blockade of the IL-1 receptor in CP infected wild-type mice …

Hypervirulent Chlamydia Trachomatis Clinical Strain Is A Recombinant Between Lymphogranuloma Venereum (L(2)) And D Lineages, Naraporn Somboonna, Raymond Wan, David M. Ojcius, Matthew A. Pettengill, Sandeep J. Joseph, Alexander Chang, Ray Hsu, Timothy D. Read, Deborah Dean

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Chlamydia trachomatis is an obligate intracellular bacterium that causes a diversity of severe and debilitating diseases worldwide. Sporadic and ongoing outbreaks of lymphogranuloma venereum (LGV) strains among men who have sex with men (MSM) support the need for research on virulence factors associated with these organisms. Previous analyses have been limited to single genes or genomes of laboratory-adapted reference strain L₂/434 and outbreak strain L₂b/UCH-1/proctitis. We characterized an unusual LGV strain, termed L₂c, isolated from an MSM with severe hemorrhagic proctitis. L₂c developed nonfusing, grape-like inclusions and a cytotoxic phenotype in culture, …

Activation Of Multiple Apoptotic Pathways In Human Nasopharyngeal Carcinoma Cells By The Prenylated Isoflavone, Osajin, Tsung-Teng Huang, Fu-Guo Liu, Chia-Fong Wei, Chia-Chen Lu, Chang-Chieh Chen, Hung-Chi Lin, David M. Ojcius, Hsin-Chih Lai

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Osajin is a prenylated isoflavone showing antitumor activity in different tumor cell lines. The underlying mechanism of osajin-induced cancer cell death is not clearly understood. In the present study, the mechanisms of osajin-induced cell death of human nasopharyngeal carcinoma (NPC) cells were explored. Osajin was found to significantly induce apoptosis of NPC cells in a dose- and time-dependent manner. Multiple molecular effects were observed during osajin treatment including a significant loss of mitochondrial transmembrane potential, release of cytochrome c into the cytosol, enhanced expression of Fas ligand (FasL), suppression of glucose-regulated protein 78 kDa (GRP78), and activation of caspases-9, -8, …

The Impact Of Tricaine Methanesulfonate, 2-Phenoxyethanol, And Carvone-Methyl Salicylate On The Innate Immune Response Of Zebrafish (Danio Rerio), Charles R. Wulff

Honors Theses

Anesthesia plays a vital role in the maintenance of aquaculture species, where it is used to minimize stress during complex handling tasks such as transport, assessment, and harvesting. However, anesthetics have been shown to suppress the innate immune response, which could impact immunity and increase risk of infection. Tricaine methanesulfonate (MS-222) and 2-Phenoxyethanol (2-PE) represent two of the most commonly used anesthetics in aquaculture, with R-(+)-carvone, in the form of carvone-methyl salicylate (CMS) has recently been proposed as an alternative anesthetic for food fish. These three anesthetics were used to assess the influence of anesthetics on the immune system of …

Enhancement Of Reactive Oxygen Species Production And Chlamydial Infection By The Mitochondrial Nod-Like Family Member Nlrx1, Ali A. Abdul-Sater, Najwene Saïd-Sadier, Verissa M. Lam, Bhavni Singh, Matthew A. Pettengill, Fraser Soares, Ivan Tattoli, Simone Lipinski, Stephen E. Girardin, Philip Rosenstiel, David M. Ojcius

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Chlamydia trachomatis infections cause severe and irreversible damage that can lead to infertility and blindness in both males and females. Following infection of epithelial cells, Chlamydia induces production of reactive oxygen species (ROS). Unconventionally, Chlamydiae use ROS to their advantage by activating caspase-1, which contributes to chlamydial growth. NLRX1, a member of the Nod-like receptor family that translocates to the mitochondria, can augment ROS production from the mitochondria following Shigella flexneri infections. However, in general, ROS can also be produced by membrane-bound NADPH oxidases. Given the importance of ROS-induced caspase-1 activation in growth of the chlamydial vacuole, we investigated the …