Life Sciences Commons^™

Evidence-Based Toxicology For The 21st Century: Opportunities And Challenges, Martin L. Stephens, Melvin E. Andersen, Richard A. Becker, Kellyn Betts, Kim Boekelheide, Ed Carney, Robert Chapin, Dennis Devlin, Suzanne C. Fitzpatrick, John R. Fowle Iii, Patricia Harlow, Thomas Hartung, Sebastian Hoffman, Michael P. Holsapple, Abigail Jacobs, Richard Judson, Olga Naidenko, Tim Pastoor, Grace Patlewicz, Andrew Rowan, Roberta Scherer, Rashid Shaikh, Ted Simon, Douglas Wolf, Joanne Zurlo

Martin Stephens, PhD

The Evidence-based Toxicology Collaboration (EBTC) was established recently to translate evidence-based approaches from medicine and health care to toxicology in an organized and sustained effort. The EBTC held a workshop on “Evidence-based Toxicology for the 21st Century: Opportunities and Challenges” in Research Triangle Park, North Carolina, USA on January 24-25, 2012. The presentations largely reflected two EBTC priorities: to apply evidence-based methods to assessing the performance of emerging pathwaybased testing methods consistent with the 2007 National Research Council report on “Toxicity Testing in the 21st Century” as well as to adopt a governance structure and work processes to move that …

Adaptation Of The Systematic Review Framework To The Assessment Of Toxicological Test Methods: Challenges And Lessons Learned With The Zebrafish Embryotoxicity Test, Martin L. Stephens, Sevcan Gül Akgün-Ölmez, Sebastian Hoffman, Rob De Vries, Burkhard Flick, Thomas Hartung, Manoj Lalu, Alexandra Maertens, Hilda Witters, Robert Wright, Katya Tsaioun

Martin Stephens, PhD

Systematic review methodology is a means of addressing specific questions through structured, consistent, and transparent examinations of the relevant scientific evidence. This methodology has been used to advantage in clinical medicine, and is being adapted for use in other disciplines. Although some applications to toxicology have been explored, especially for hazard identification, the present preparatory study is, to our knowledge, the first attempt to adapt it to the assessment of toxicological test methods. As our test case, we chose the zebrafish embryotoxicity test (ZET) for developmental toxicity and its mammalian counterpart, the standard mammalian prenatal development toxicity study, focusing the …

Practical Considerations In Regenerative Medicine Research: Iacucs, Ethics, And The Use Of Animals In Stem Cell Studies, Susan Vandewoude, Bernard E. Rollin

Bernard Rollin, PhD

The intent of US federal laws mandating IACUC review of animal-related activities was to satisfy contemporary socioethical concerns by introducing deliberations about ethics and animal welfare into the research process when animals are used. These laws and the system they chartered have worked well for the most part in providing opportunities for consideration of animal welfare as a vital part of animal research. As a result, investigators today are far less naïve about the ethical issues raised by research on animals and typically more sympathetic about the need for such consideration. As evidence of this growing awareness, the literature on …

Animal Organs In Humans: Uncalculated Risks And Unanswered Questions, Gillian R. Langley, Joyce D'Silva

Gill Langley, PhD

This report, produced jointly by the British Union for the Abolition of Vivisection and Compassion in World Farming, fills a number of significant gaps in the current debate about xenotransplantation.

In this report we also summarise the ethical and welfare issues concerning experiments on animals for xenotransplant research and their possible use as source animals for organs. Both these aspects are responsible for much pain and distress caused to many animals. We prefer the term “source animals” to “donor animals”, because animals do not choose to donate their organs for xenotransplantation.

Control Of Antiviral Innate Immune Response By Protein Geranylgeranylation, Shigao Yang, Zhaozhao Jiang, Katherine A. Fitzgerald, Donghai Wang

Katherine A. Fitzgerald

The mitochondrial antiviral signaling protein (MAVS) orchestrates host antiviral innate immune response to RNA virus infection. However, how MAVS signaling is controlled to eradicate virus while preventing self-destructive inflammation remains obscure. Here, we show that protein geranylgeranylation, a posttranslational lipid modification of proteins, limits MAVS-mediated immune signaling by targeting Rho family small guanosine triphosphatase Rac1 into the mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) at the mitochondria-ER junction. Protein geranylgeranylation and subsequent palmitoylation promote Rac1 translocation into MAMs upon viral infection. MAM-localized Rac1 limits MAVS' interaction with E3 ligase Trim31 and hence inhibits MAVS ubiquitination, aggregation, and activation. Rac1 also facilitates …

Contribution Of Animal Models To Contemporary Understanding Of Attention Deficit Hyperactivity Disorder, Constança Carvalho, Mariana Vieira Crespo, Luísa Ferreira Bastos, Andrew Knight, Luís Vincente

Andrew Knight, PhD

Attention Deficit Hyperactivity Disorder (ADHD) is a poorly understood neurodevelopmental disorder of multifactorial origin. Animal-based research has been used to investigate ADHD etiology, pathogenesis and treatment, but the efficacy of this research for patients has not yet been systematically evaluated. Such evaluation is important given the resource consumption and ethical concerns incurred by animal use.

We used the citation tracking facility within Web of Science to locate citations of original research papers on animal models related to ADHD published prior to 2010 identified in PubMed by relevant search terms. Human medical papers citing those animal studies were carefully analyzed by …

Nutrient Excess And Ampk Downregulation In Incubated Skeletal Muscle And Muscle Of Glucose Infused Rats, Kimberly A. Coughlan, Thomas W. Balon, Rudy J. Valentine, Robert Petrocelli, Vera Schultz, Amana Brandon, Gregory J. Cooney, Edward W. Kraegen, Neil B. Ruderman, Asish K. Saha

Rudy Valentine

We have previously shown that incubation for 1h with excess glucose or leucine causes insulin resistance in rat extensor digitorum longus (EDL) muscle by inhibiting AMP-activated protein kinase (AMPK). To examine the events that precede and follow these changes, studies were performed in rat EDL incubated with elevated levels of glucose or leucine for 30min-2h. Incubation in high glucose (25mM) or leucine (100μM) significantly diminished AMPK activity by 50% within 30min, with further decreases occurring at 1 and 2h. The initial decrease in activity at 30min coincided with a significant increase in muscle glycogen. The subsequent decreases at 1h were …

Inhibition Of Triggering Receptor Expressed On Myeloid Cells 1 Ameliorates Inflammation And Macrophage And Neutrophil Activation In Alcoholic Liver Disease In Mice, David Tornai, Istvan Furi, Zu T. Shen, Alexander B. Sigalov, Sahin Coban, Gyongyi Szabo

Gyongyi Szabo

Alcoholic liver disease (ALD) is characterized by macrophage and neutrophil leukocyte recruitment and activation in the liver. Damage- and pathogen-associated molecular patterns contribute to a self-perpetuating proinflammatory state in ALD. Triggering receptor expressed on myeloid cells 1 (TREM-1) is a surface receptor that amplifies inflammation induced by toll-like receptors (TLRs) and is expressed on neutrophils and monocytes/macrophages. We hypothesized that TREM-1 signaling contributes to proinflammatory pathway activation in ALD. Using an in vivo ALD model in mice, we tested the effects of ligand-independent TREM-1 inhibitory peptides that were formulated into human high-density lipoprotein (HDL)-mimicking complexes GF9-HDL and GA/E31-HDL. As revealed …

An Assessment Of The Use Of Chimpanzees In Hepatitis C Research Past, Present And Future: 1. Validity Of The Chimpanzee Model, Jarrod Bailey

Jarrod Bailey, PhD

The USA is the only significant user of chimpanzees in biomedical research in the world, since many countries have banned or limited the practice due to substantial ethical, economic and scientific concerns. Advocates of chimpanzee use cite hepatitis C research as a major reason for its necessity and continuation, in spite of supporting evidence that is scant and often anecdotal. This paper examines the scientific and ethical issues surrounding chimpanzee hepatitis C research, and concludes that claims of the necessity of chimpanzees in historical and future hepatitis C research are exaggerated and unjustifiable, respectively. The chimpanzee model has several major …

Chimpanzee Research: An Examination Of Its Contribution To Biomedical Knowledge And Efficacy In Combating Human Diseases, Jarrod Bailey, Jonathan Balcombe, Theodora Capaldo

Jarrod Bailey, PhD

Research on captive chimpanzees incurs considerable animal welfare, ethical and financial costs. Advocates of such research claim these costs are outweighed by substantial advancements in biomedical knowledge, and that the genetic similarity of chimpanzees to humans enables the former to make critical contributions to preventing, diagnosing and combating human diseases. To assess these claims, we examined the disciplines investigated in 749 studies of captive chimpanzees published from 1995-2004 inclusive, and subjected 95 randomly selected papers to a detailed citation analysis:

49.5% (47/95) of papers had not been cited at the time of this study; 38.5% (34/95) were cited by 116 …

An Assessment Of The Use Of Chimpanzees In Hepatitis C Research Past, Present And Future: 2. Alternative Replacement Methods, Jarrod Bailey

Jarrod Bailey, PhD

The use of chimpanzees in hepatitis C virus (HCV) research was examined in the report associated with this paper (1: Validity of the Chimpanzee Model), in which it was concluded that claims of past necessity of chimpanzee use were exaggerated, and that claims of current and future indispensability were unjustifiable. Furthermore, given the serious scientific and ethical issues surrounding chimpanzee experimentation, it was proposed that it must now be considered redundant — particularly in light of the demonstrable contribution of alternative methods to past and current scientific progress, and the future promise that these methods hold. This paper builds on …

Lateralized Difference In Tympanic Membrane Temperature: Emotion And Hemispheric Activity, Ruth E. Propper, Tad T. Brunyé

Ruth Propper

We review literature examining relationships between tympanic membrane temperature (TMT), affective/motivational orientation, and hemispheric activity. Lateralized differences in TMT might enable real-time monitoring of hemispheric activity in real-world conditions, and could serve as a corroborating marker of mental illnesses associated with specific affective dysregulation. We support the proposal that TMT holds potential for broadly indexing lateralized brain physiology during tasks demanding the processing and representation of emotional and/or motivational states, and for predicting trait-related affective/motivational orientations. The precise nature of the relationship between TMT and brain physiology, however, remains elusive. Indeed the limited extant research has sampled different participant populations …

Proteomic Profiling Of Serum Derived Exosomes From Prostate Cancer Patients, David Turay

David Turay, MD

Touted among the major achievements in the diagnosis and management of Prostate cancer (PCa) in the past few decades has been, the dramatic decline of men with advanced/metastatic PCa at diagnosis coupled with a significant improvement ( >90%) in the five and ten year survival rates of the disease. Non-palpable PCa (potentially clinically treatable disease) now accounts for 70-80% of all newly diagnosed cases of PCa. Preceding these changes by about a decade was the introduction of Prostatic Specific Antigen (PSA) into clinical practice; first as biomarker for monitoring response to therapy and subsequently as a complementary screening tool. It …

Survival Advantage Of Both Human Hepatocyte Xenografts And Genome-Edited Hepatocytes For Treatment Of Alpha-1 Antitrypsin Deficiency, Florie Borel, Qiushi Tang, Gwladys Gernoux, Cynthia Greer, Ziqiong Wang, Adi Barzel, Mark A. Kay, Leonard D. Shultz, Dale L. Greiner, Terence R. Flotte, Michael A. Brehm, Christian Mueller

Christian Mueller

Hepatocytes represent an important target for gene therapy and editing of single-gene disorders. In alpha-1 antitrypsin (AAT) deficiency, one missense mutation results in impaired secretion of AAT. In most patients, lung damage occurs due to a lack of AAT-mediated protection of lung elastin from neutrophil elastase. In some patients, accumulation of misfolded PiZ mutant AAT protein triggers hepatocyte injury, leading to inflammation and cirrhosis. We hypothesized that correcting the Z mutant defect in hepatocytes would confer a selective advantage for repopulation of hepatocytes within an intact liver. A human PiZ allele was crossed onto an immune-deficient (NSG) strain to create …

Use Of Imaging Biomarkers To Assess Perfusion And Glucose Metabolism In The Skeletal Muscle Of Dystrophic Mice, Nabeel Ahmad, Ian Welch, Robert Grange, Jennifer Hadway, Savita Dhanvantari, David Hill, Ting-Yim Lee, Lisa M Hoffman

Lisa Hoffman

BACKGROUND: Duchenne muscular dystrophy (DMD) is a severe neuromuscular disease that affects 1 in 3500 boys. The disease is characterized by progressive muscle degeneration that results from mutations in or loss of the cytoskeletal protein, dystrophin, from the glycoprotein membrane complex, thus increasing the susceptibility of contractile muscle to injury. To date, disease progression is typically assessed using invasive techniques such as muscle biopsies, and while there are recent reports of the use of magnetic resonance, ultrasound and optical imaging technologies to address the issue of disease progression and monitoring therapeutic intervention in dystrophic mice, our study aims to validate …

A Review Of The Institute Of Medicine’S Analysis Of Using Chimpanzees In Biomedical Research, Robert C. Jones, Ray Greek

Robert C. Jones, PhD

We argue that the recommendations made by the Institute of Medicine’s 2011 report, Chimpanzees in Biomedical and Behavioral Research: Assessing the Necessity, are methodologically and ethically confused. We argue that a proper understanding of evolution and complexity theory in terms of the science and ethics of using chimpanzees in biomedical research would have had led the committee to recommend not merely limiting but eliminating the use of chimpanzees in biomedical research. Specifically, we argue that a proper understanding of the difference between the gross level of examination of species and examinations on finer levels can shed light on important methodological …

Impact Of The C-Mybe308g Mutation On Mouse Myelopoiesis And Dendritic Cell Development, Peter Papathanasiou, Sawang Petvises, Ying-Ying Hey, Andrew C Perkins, Helen C O'Neill

Helen O'Neill

Booreana mice carrying the c-Myb308G point mutation were analyzed to determine changes in early hematopoiesis in the bone marrow and among mature cells in the periphery. This point mutation led to increased numbers of early hematopoietic stem and progenitor cells (HSPCs), with a subsequent reduction in the development of B cells, erythroid cells, and neutrophils, and increased numbers of myeloid cells and granulocytes. Myelopoiesis was further investigated by way of particular subsets affected. A specific question addressed whether booreana mice contained increased numbers of dendritic-like cells (L-DC subset) recently identified in the spleen, since L-DCs arise in vitro by direct …

The Glia Response After Peripheral Nerve Injury: A Comparison Between Schwann Cells And Olfactory Ensheathing Cells And Their Uses For Neural Regenerative Therapies, Matthew J Barton, James St John, Alison Wright, Jenny Ekberg

Jenny Ekberg

The peripheral nervous system (PNS) exhibits a much larger capacity for regeneration than the central nervous system (CNS). One reason for this difference is the difference in glial cell types between the two systems. PNS glia respond rapidly to nerve injury by clearing debris from the injury site, supplying essential growth factors and providing structural support; all of which enhances neuronal regeneration. Thus, transplantation of glial cells from the PNS is a very promising therapy for injuries to both the PNS and the CNS. There are two key types of PNS glia: olfactory ensheathing cells (OECs), which populate the olfactory …

Changes In Dietary Patterns And Body Composition Within 12 Months Of Liver Transplantation, Mccoy Simone, Katrina Campbell, Annie-Claude Lassemillante, Matthew P. Wallen, Jonathan Fawcett, Maree Jarrett, Graeme A. Macdonald, Ingrid J. Hickman

Katrina Campbell

Background:

Cardiometabolic risk factors are increasing in liver transplant recipients (LTR). Influencing dietary factors have not been assessed. The aim of this observational study was to assess changes in weight, metabolic function, dietary intake and eating behaviours in the first year after orthotopic liver transplantation (OLT).

Methods:

Consecutive recruitment of 17 patients (14 males) awaiting OLT at a single tertiary hospital. Dietary intake, food behaviours and anthropometry were recorded at baseline, and 6 and 12 months post-transplant.

Results:

By 12 months, patients had gained on average 7.3% of body weight. The prevalence of overweight or obesity increased from baseline 53% …

Freshwater Fungal Infections, Dennis J. Baumgardner

Dennis J. Baumgardner, MD

Fungal infections as a result of freshwater exposure or trauma are fortunately rare. Etiologic agents are varied, but commonly include filamentous fungi and Candida. This narrative review describes various sources of potential freshwater fungal exposure and the diseases that may result, including fungal keratitis, acute otitis externa and tinea pedis, as well as rare deep soft tissue or bone infections and pulmonary or central nervous system infections following traumatic freshwater exposure during natural disasters or near-drowning episodes. Fungal etiology should be suspected in appropriate scenarios when bacterial cultures or molecular tests are normal or when the infection worsens or fails …

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

David M. Ojcius

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 …

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

David M. Ojcius

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 …

Tolerance Of The Fetus By The Maternal Immune System: Role Of Inflammatory Mediators At The Feto-Maternal Interface, Colette Kanellopoulos-Langevin, Stephane M. Caucheteux, Philippe Verbeke, David M. Ojcius

David M. Ojcius

The adaptive immune system of placental mammals has evolved to tolerate the fetus. Rejection of the fetus by adaptive immune responses is therefore a rare event, with abortion being caused more frequently by inflammation in the placenta. This review will cover recent aspects of immune privilege and the innate immune system at the feto-maternal interface, citing examples of the role played by microbial infections in fetal demise.

Ph And Calcium Dependence Of Hemolysis Due To Rickettsia Prowazekii: Comparison With Phospholipase Activity, David M. Ojcius, M. Thibon, C. Mounier, Alice Dautry-Varsat

David M. Ojcius

Rickettsia prowazekii invades nucleated cells through phagocytosis and subsequently proliferates in the cytoplasm of the host cell. Hemolysis and a phospholipase A2 (PLA2) activity at neutral pHs have previously been reported; even though the phagosomal environment is most likely acidic. We here show that R. prowazekii and R. typhi also lyse erythrocytes at mildly acidic pHs, compatible with an early phagosomal compartment. For R. prowazekii, hemolysis at an acidic pH but not a neutral pH is enhanced by Ca2+, raising the possibility that more than one membranolytic factor may be produced by the rickettsiae. The rickettsiae alone display PLA2 activity, …

The Danger Signal Adenosine Induces Persistence Of Chlamydial Infection Through Stimulation Of A2b Receptors, Matthew A. Pettengill, Verissa W. Lam, David M. Ojcius

David M. Ojcius

Infections with intracellular bacteria such as chlamydiae affect the majority of the world population. Infected tissue inflammation and granuloma formation help contain the short-term expansion of the invading pathogen, leading also to local tissue damage and hypoxia. However, the effects of key aspects of damaged inflamed tissues and hypoxia on continued infection with intracellular bacteria remain unknown. We find that development of Chlamydia trachomatis is reversibly retarded by prolonged exposure of infected cells to extracellular adenosine, a hallmark of hypoxia and advanced inflammation. In epithelial cells, this effect was mediated by the A2b adenosine receptor, unique in the adenosine receptor …

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

David M. Ojcius

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 …

Susceptibility Of Chlamydia Trachomatis To The Excipient Hydroxy-Ethylcellulose: Ph And Concentration Dependence Of Antimicrobial Activity, Ali A. Abdul-Sater, David M. Ojcius, M. P. Meyer

David M. Ojcius

Hydroxyethyl cellulose (HEC) is used as a neutral excipient in microbicides used against sexually transmitted pathogens. However, HEC inhibits the infection of cervical epithelial cells by Chlamydia trachomatis at pH 5 in a concentration-dependent manner. At pH 7, infection is inversely dependent on the concentration of HEC, possibly due to pH-dependent calcium sequestration.

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

David M. Ojcius

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 …

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

David M. Ojcius

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. …

Role Of Proapoptotic Bax In Propagation Of Chlamydia Muridarum (The Mouse Pneumonitis Strain Of Chlamydia Trachomatis) And The Host Inflammatory Response, Jean-Luc Perfettini, David M. Ojcius, Charles W. Andrews Jr., Stanley J. Korsmeyer, Roger G. Rank, Toni Darville

David M. Ojcius

The BCL-2 family member BAX plays a critical role in regulating apoptosis. Surprisingly, bax-deficient mice display limited phenotypic abnormalities. Here we investigate the effect of BAX on infection by the sexually transmitted pathogen,Chlamydia muridarum (the mouse pneumonitis strain ofChlamydia trachomatis). Bax −/−cells are relatively resistant to Chlamydia-induced apoptosis, and fewer bacteria are recovered after two infection cycles from Bax −/− cells than from wild-type cells. These results suggest that BAX-dependent apoptosis may be used to initiate a new round of infection, most likely by releasingChlamydia-containing apoptotic bodies from infected cells that could be internalized by neighboring uninfected cells. Nonetheless, infected …