Medical Immunology Commons^™

Fit For Genomic And Proteomic Purposes: Sampling The Fitness Of Nucleic Acid And Protein Derivatives From Formalin Fixed Paraffin Embedded Tissue., Anna Yakovleva, Jordan L Plieskatt, Sarah Jensen, Razan Humeida, Jonathan Lang, Guangzhao Li, Paige Bracci, Sylvia Silver, Jeffrey Michael Bethony

Microbiology, Immunology, and Tropical Medicine Faculty Publications

The demand for nucleic acid and protein derivatives from formalin-fixed paraffin-embedded (FFPE) tissue has greatly increased due to advances in extraction and purification methods, making these derivatives available for numerous genomic and proteomic platforms. Previously, DNA, RNA, microRNA (miRNA), or protein derived from FFPE tissue blocks were considered “unfit” for such platforms, as the process of tissue immobilization by FFPE resulted in cross-linked, fragmented, and chemically modified macromolecules. We conducted a systematic examination of nucleic acids and proteins co-extracted from 118 FFPE blocks sampled from the AIDS and Cancer Specimen Resource (ACSR) at The George Washington University after stratification by …

A Modified Fasp Protocol For High-Throughput Preparation Of Protein Samples For Mass Spectrometry., Jeremy Potriquet, Marut Laohaviroj, Jeffrey M Bethony, Jason Mulvenna

Microbiology, Immunology, and Tropical Medicine Faculty Publications

o facilitate high-throughput proteomic analyses we have developed a modified FASP protocol which improves the rate at which protein samples can be processed prior to mass spectrometry. Adapting the original FASP protocol to a 96-well format necessitates extended spin times for buffer exchange due to the low centrifugation speeds tolerated by these devices. However, by using 96-well plates with a more robust polyethersulfone molecular weight cutoff membrane, instead of the cellulose membranes typically used in these devices, we could use isopropanol as a wetting agent, decreasing spin times required for buffer exchange from an hour to 30 minutes. In a …

Schistosoma Mansoni Reinfection: Analysis Of Risk Factors By Classification And Regression Tree (Cart) Modeling., Andréa Gazzinelli, Roberta Oliveira-Prado, Leonardo Ferreira Matoso, Bráulio M Veloso, Gisele Andrade, Helmut Kloos, Jeffrey M Bethony, Renato M Assunção, Rodrigo Correa-Oliveira

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Praziquantel (PZQ) is an effective chemotherapy for schistosomiasis mansoni and a mainstay for its control and potential elimination. However, it does not prevent against reinfection, which can occur rapidly in areas with active transmission. A guide to ranking the risk factors for Schistosoma mansoni reinfection would greatly contribute to prioritizing resources and focusing prevention and control measures to prevent rapid reinfection. The objective of the current study was to explore the relationship among the socioeconomic, demographic, and epidemiological factors that can influence reinfection by S. mansoni one year after successful treatment with PZQ in school-aged children in Northeastern Minas …

Mycobacterium Tuberculosis Reactivates Latent Hiv-1 In T Cells In Vitro, Erica Larson, Camille Novis, Laura Martins, Amanda Macedo, Kadyn Kimball, Alberto Bosque, Vincent Planelles, Louis Barrows

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Following proviral integration into the host cell genome and establishment of a latent state, the human immunodeficiency virus type 1 (HIV-1) can reenter a productive life cycle in response to various stimuli. HIV-1 reactivation occurs when transcription factors, such as nuclear factor-κB (NF-κB), nuclear factor of activated T cells (NFAT), and activator protein -1 (AP-1), bind cognate sites within the long terminal repeat (LTR) region of the HIV-1 provirus to promote transcription. Interestingly, pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) can reactivate latent HIV-1 through activation of the transcription factor NF-κB. Some PRRs are expressed on central …

Downregulated Il-21 Response And T Follicular Helper Cell Exhaustion Correlate With Compromised Cd8 T Cell Immunity During Chronic Toxoplasmosis, Magali M. Moretto, Sujin Hwang, Imtiaz A. Khan

Microbiology, Immunology, and Tropical Medicine Faculty Publications

CD8 T cells are important for maintaining the chronicity of Toxoplasma gondii infection. In a T. gondii encephalitis susceptible model, we recently demonstrated that CD4 T cells play an essential helper role in the maintenance of the effector response and CD8 T cell dysfunctionality was linked to CD4 T cell exhaustion. However, CD4 T cells are constituted of different subsets with various functions and the population(s) providing help to the CD8 T cells has not yet been determined. In the present study, Tfh cells (T follicular helper), which are known to be essential for B cell maturation and are one …

Ancylostoma Ceylanicum Infective Third-Stage Larvae Are Activated By Co-Culture With Ht-29-Mtx Intestinal Epithelial Cells, Caitlin Feather, John M. Hawdon, John March

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Background

Human hookworm larvae arrest development until they enter an appropriate host. This makes it difficult to access the larvae for studying larval development or host-parasite interactions. While there are in vivo and in vitro animal models of human hookworm infection, there is currently no human, in vitro model. While animal models have provided much insight into hookworm biology, there are limitations to how closely this can replicate human infection. Therefore, we have developed a human, in vitro model of the initial phase of hookworm infection using intestinal epithelial cell culture.

Results

Co-culture of the human hookworm Ancylostoma ceylanicum with …

The Effect Of K562-Il21-2 Plasma Membrane Particles On The Proliferation Of Natural Killer Cells To Fight Cancer, Michelle Prophete

Honors Undergraduate Theses

Immunotherapy has emerged as a current and future paradigm of cancer treatment, which utilizes the body’s immune system to eradicate cancer. Natural Killer (NK) cells as part of the innate immune system have immense potential in their anti-tumor cytotoxic activities and host cell surveillance properties. NK cells comprise approximately five to fifteen percent of peripheral blood lymphocytes and can be proliferated in vitro using recently developed methods with co-cultures with feeder cells (derived from engineered tumor cells) or plasma membrane (PM) particles, produced from the fore mentioned feeder cells, in combination with soluble cytokines. For efficient growth and maintenance of …

A Fashi Lymphoproliferative Phenotype Reveals Non-Apoptotic Fas Signalling In Htlv-1-Associated Neuroinflammation., Soraya Maria Menezes, Fabio E Leal, Tim Dierckx, Ricardo Khouri, Daniele Decanine, Gilvaneia Silva-Santos, +Several Additional Authors

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Human T-cell lymphotropic virus (HTLV)-1 was the first human retrovirus to be associated to cancer, namely Adult T-cell Leukemia (ATL), but its pathogenesis remains enigmatic, since only a minority of infected individuals develops either ATL or the neuroinflammatory disorder HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). A functional FAS -670 polymorphism in an interferon (IFN)-regulated STAT1-binding site has been associated to both ATL and HAM/TSP susceptibility. Fashi T stem cell memory (Tscm) cells have been identified as the hierarchical apex of ATL, but have not been investigated in HAM/TSP. In addition, both FAS and STAT1 have been identified in an IFN-inducible HAM/TSP …

Distinct Transcriptome Profiles Of Gag-Specific Cd8+ T Cells Temporally Correlated With The Protection Elicited By Sivδnef Live Attenuated Vaccine, Wuxun Lu, Yanmin Wu, Fangrui Ma, R. Paul Johnson, Qingsheng Li

Nebraska Center for Virology: Faculty Publications

The live attenuated vaccine (LAV) SIVmac239Δnef (SIVΔnef) confers the best protection among all the vaccine modalities tested in rhesus macaque model of HIV-1 infection. This vaccine has a unique feature of time-dependent protection: macaques are not protected at 3±5 weeks post vaccination (WPV), whereas immune protection emerges between 15 and 20 WPV. Although the exact mechanisms of the time-dependent protection remain incompletely understood, studies suggested that both cellular and humoral immunities contribute to this time-dependent protection. To further elucidate the mechanisms of protection induced by SIVΔnef, we longitudinally compared the global gene expression profiles of SIV Gag-CM9+ CD8+ (Gag-specific CD8+) …

Chloroviruses Have A Sweet Tooth, James L. Van Etten, Irina V. Agarkova, David D. Dunigan, Michela Tonetti, Cristina De Castro, Garry A. Duncan

Nebraska Center for Virology: Faculty Publications

Chloroviruses are large double-stranded DNA (dsDNA) viruses that infect certain isolates of chlorella-like green algae. They contain up to approximately 400 protein-encoding genes and 16 transfer RNA (tRNA) genes. This review summarizes the unexpected finding that many of the chlorovirus genes encode proteins involved in manipulating carbohydrates. These include enzymes involved in making extracellular polysaccharides, such as hyaluronan and chitin, enzymes that make nucleotide sugars, such as GDP-L-fucose and GDP-D-rhamnose and enzymes involved in the synthesis of glycans attached to the virus major capsid proteins. This latter process differs from that of all other glycoprotein containing viruses that traditionally use …

Tryptophan 375 Stabilizes The Outer-Domain Core Of Gp120 For Hiv Vaccine Immunogen Design, Duoyi Hu, Dane Bowder, Wenzhong Wei, Jesse Thompson, Mark A. Wilson, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

The outer-domain core of gp120 may serve as a better HIV vaccine immunogen than the full-length gp120 because of its greater stability and immunogenicity. In our previous report, we introduced two disulfide bonds to the outer-domain core of gp120 to fix its conformation into a CD4-bound state, which resulted in a significant increase in its immunogenicity when compared to the wild-type outer-domain core. In this report, to further improve the immunogenicity of the outer-domain core based immunogen, we have introduced a Tryptophan residue at gp120 amino acid sequence position 375 (375S/W). Our data from immunized guinea pigs indeed shows a …

Characterization Of A New Chlorovirus Type With Permissive And Non-Permissive Features On Phylogenetically Related Algal Strains, Cristian F. Quispe, Ahmed Esmael, Olivia Sonderman, Michelle Mcquinn, Irina Agarkova, Mohammed Battah, Garry A. Duncan, David D. Dunigan, Timothy P. L. Smith, Cristina Decastro, Immacolata Speciale, Fangrui Ma, James L. Van Etten

Nebraska Center for Virology: Faculty Publications

A previous report indicated that prototype chlorovirus PBCV-1 replicated in two Chlorella variabilis algal strains, NC64A and Syngen 2-3, that are ex-endosymbionts isolated from the protozoan Paramecium bursaria. Surprisingly, plaque-forming viruses on Syngen 2-3 lawns were often higher than on NC64A lawns from indigenous water samples. These differences led to the discovery of viruses that exclusively replicate in Syngen 2-3 cells, named Only Syngen (OSy) viruses. OSy-NE5, the prototype virus for the proposed new species, had a linear dsDNA genome of 327 kb with 44-nucleotide-long, incompletely base-paired, covalently closed hairpin ends. Each hairpin structure was followed by an identical …

Activation And Expansion Of Natural Killer Cells For Cancer Immunotherapy With Ex21 Exosomes, Sara Khederzadeh

Honors Undergraduate Theses

In the field of cancer immunotherapy, NK cells are recognized for their ability to provide a form of innate immunity against tumor cells. However, the average abundance of NK cells in the blood can be as low as 5% of the total lymphocyte population. As a result, it has been a focus to find novel therapies to expand NK cells in vitro while subsequently enhancing the cytotoxicity of these cells. Previously-defined methods include the minimal expansion of NK cells with high levels of cytokines such as IL-2 and IL-15, as well as co-culturing NK cells with feeder cell populations that …

Micrornas Modulate Pathogenesis Resulting From Chlamydial Infection In Mice, Laxmi Yeruva, S. Pouncey, Michael R. Eledge, Sudeepa Bhattacharya, Chunqiao Luo, Erin W. Weatherford, David M. Ojcius, Roger G. Rank

All Dugoni School of Dentistry Faculty Articles

Not all women infected with chlamydiae develop upper genital tract disease, but the reason(s) for this remains undefined. Host genetics and hormonal changes associated with the menstrual cycle are possible explanations for variable infection outcomes. It is also possible that disease severity depends on the virulence of the chlamydial inoculum. It is likely that the inoculum contains multiple genetic variants, differing in virulence. If the virulent variants dominate, then the individual is more likely to develop severe disease. Based on our previous studies, we hypothesized that the relative degree of virulence of a chlamydial population dictates the microRNA (miRNA) expression …

Reactivation Of Hiv-1 Proviruses In Immune-Compromised Mice Engrafted With Human Voa-Negative Cd4+ T Cells, Zhe Yuan, Guobin Kang, Wuxun Lu, Qingsheng Li

Nebraska Center for Virology: Faculty Publications

Background: HIV-1 infection remains incurable on antiretroviral therapy (ART) due to virus latency. To date, enhanced co-culture assays, including viral outgrowth assays (VOA), are commonly used to measure HIV-1 latent reservoirs and evaluate latency-reversing agents (LRAs). However, VOA can only reactivate a small fraction of intact proviruses.

Methods: To explore the utility of NOD scid gamma (NSG) mice as an in vivo model to reactivate HIV-1 proviruses from VOA-negative CD4+ T cells, resting CD4+ T cells from an HIV-1 latently infected individual were isolated and the human CD4+ T cells corresponding to VOA-positive and VOA-negative CD4+ T cells were engrafted …

A Behavioral And Neuroimmune System Model Of The Effects Of Chronic Low-Level Lead Exposure In Young Male C57bl/6j Mice, Mayra Gisel Flores-Montoya

Open Access Theses & Dissertations

Chronic low-level lead exposure reduces memory in children however the brain mechanisms mediating these effects are not known. In previous studies we showed that early lead exposure reduced olfactory memory and exploratory behavior in young mice, and reduced microglia cell density in hippocampus/dentate gyrus. The present studies aimed to identify additional behavioral tests that were sensitive to early low-level lead exposure in young mice; and to examine whether microglia upregulated factors known to promote cell migration. Seventy-two C57BL/6J male mice were exposed to 0 ppm (controls), 30 ppm (low-dose), or 430 ppm (high-dose) of lead acetate via dams' milk from …

Vitamin D Improves Selected Metabolic Parameters But Not Neuropsychological Or Quality Of Life Indices In Osa: A Pilot Study, Conor Kerley, Katrina Hutchinson, Jessica Branham, Aisling Mcgowan, John Faul, Liam Cormican

Articles

Study Objectives: Our group and others have reported a high rate of vitamin D deficiency in obstructive sleep apnea (OSA), where vitamin D levels (25(OH) D) correlate negatively with OSA severity and some of its associated metabolic alterations. Data regarding vitamin D supplementation in OSA are lacking. We wanted to evaluate the effect of vitamin D3 supplementation on OSA symptoms and metabolic parameters. Methods: We conducted a pilot, double-blind, randomized, placebo-controlled trial of daily supplementation with 4,000 IU vitamin D3 (D3) or placebo (PL). We studied 19 Caucasian adults (14 male, mean age 55 y, mean body mass index [BMI] …

Vitamin D Receptor Variants And Uncontrolled Asthma, Conor Kerley, Katrina Hutchinson, John Faul, Peter Greally, David Coghlan, Basil Elnazir, Michael Louw, Yury Rochev

Articles

BACKGROUND: Asthma is a common childhood respiratory disease, affecting around 20% of Irish children. In other populations, vitamin D receptor (VDR) polymorphisms have been associated with asthma risk. We aimed to investigate the association between 2 VDR polymorphisms and uncontrolled paediatric asthma. METHODS: 44 asthmatic children and 57 healthy volunteers were studied. The VDR TaqI gene variant in exon 9 (T/C) (rs731236) and ApaI (rs7975232) in intron 8 (C/T) were determined, using TaqMan®Assays. The lung function, serum 25-hydroxyvitamin D (25OHD) levels and other biomarkers of allergy, immunity, airway and systemic inflammation were assessed. RESULTS: The distribution of T and C …

Nitrate-Rich Beetroot Juice Selectively Lowers Ambulatory Pressures And Ldl Cholesterol In Uncontrolled But Not Controlled Hypertension: A Pilot Study., Conor Kerley, Eamon Dolan, Liam Cormican

Articles

Background Dietary nitrate has been shown to increase nitrate/nitrite levels in multiple populations, with potential blood pressure lowering effects. However, there are few reports among hypertensives. Aims We aimed to assess the effect of daily nitrate in subject with controlled hypertension vs. uncontrolled hypertension. Methods On day 0, hypertensives wore an ambulatory BP monitor (ABPM) for 24h and fasting blood was taken. Subjects then consumed concentrated beetroot juice (12.9mmol nitrate) for 14 consecutive days. On day 14 subjects consumed their last nitrate dose after fasting blood was drawn and again had an ABPM for 24h. Results According to baseline ABPM, …

Immunogenicity And Protective Efficacy Of The Dar-901 Booster Vaccine In A Murine Model Of Tuberculosis, Timothy Lahey, Dominick Laddy, Krystal Hill, Jacqueline Schaeffer

Dartmouth Scholarship

The development of a novel tuberculosis vaccine is a leading global health priority. SRL172, an inactivated, whole-cell mycobacterial vaccine, was safe, immunogenic and reduced the incidence of culture-confirmed tuberculosis in a phase III trial in HIV-infected and BCG immunized adults in Tanzania. Here we describe the immunogenicity and protective efficacy of DAR-901, a booster vaccine against tuberculosis manufactured from the same seed strain using a new scalable method.

The Vibrio Cholerae Minor Pilin Tcpb Initiates Assembly And Retraction Of The Toxin-Coregulated Pilus, Dixon Ng, Tony Harn, Tuba Altindal, Subramania Kolappan, Jarrad Marles, Rajan Lala, Ingrid Spielman, Yang Gao, Caitlyn Hauke, Gabriela Kovacikova

Dartmouth Scholarship

Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent …

Applying Multiple Data Collection Tools To Quantify Human Papillomavirus Vaccine Communication On Twitter., Philip M. Massey, Amy Leader, Elad Yom-Tov, Alexandra Budenz, Kara Fisher, Ann C. Klassen

Department of Medical Oncology Faculty Papers

BACKGROUND: Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States. There are several vaccines that protect against strains of HPV most associated with cervical and other cancers. Thus, HPV vaccination has become an important component of adolescent preventive health care. As media evolves, more information about HPV vaccination is shifting to social media platforms such as Twitter. Health information consumed on social media may be especially influential for segments of society such as younger populations, as well as ethnic and racial minorities.

OBJECTIVE: The objectives of our study were to quantify HPV vaccine communication on …

A Novel Codon-Optimized Siv Gag-Pol Immunogen For Gene-Based 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 …

Immune Monitoring In Recipients Of Combined Living Donor Kidney And Hematopoietic Stem/Facilitating Cell Transplants., Mark Dewayne Badder

Electronic Theses and Dissertations

Solid organ transplantation coupled with a hematopoietic stem cell transplant from the organ donor allows for the recipient to cease immunosuppressive therapy after transplant via a chimeric immune system. This beneficial effect of stem cell transplants is negatively affected by graft versus host disease (GVHD). Better understanding of the donor and recipient’s immune system is vital to mitigating graft versus host disease and induction of donor chimerism without GVHD. In this study, flow cytometry was used to characterize immune cells of the recipients’ before and up to eighteen months post transplantation. The recipients were categorized into their respective chimeric groups. …

Reexamining Chronic Toxoplasma Gondii Infection: Surprising Activity For A "Dormant" Parasite, Anthony P. Sinai, Elizabeth A. Watts, Animesh Dhara, Robert D. Murphy, Matthew S. Gentry, Abhijit R. Patwardhan

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Purpose of Review

Despite over a third of the world’s population being chronically infected with Toxoplasma gondii, little is known about this largely asymptomatic phase of infection. This stage is mediated in vivo by bradyzoites within tissue cysts. The absence of overt symptoms has been attributed to the dormancy of bradyzoites. In this review, we reexamine the conventional view of chronic toxoplasmosis in light of emerging evidence challenging both the nature of dormancy and the consequences of infection in the CNS.

Recent Findings

New and emerging data reveal a previously unrecognized level of physiological and replicative capacity of bradyzoites …

Final Design Report: Allergen Mixing Assistant (Ama) Micro-Refrigeration Redesigning, Mitchell Parks, Minwoo (Michael) Suh

Mechanical Engineering

Abstract

Allergen Mixing Assistant (AMA) by Xtract Solutions is a device designed to more “effectively refrigerate, organize, and mix allergenic extracts”. Although Xtract Solutions intended the product to be fully automated, the company has decided against its automation and declared its current design as a minimum viable product whose components are too expensive, difficult to source and complex. Therefore, Cal Poly AMA design team - Mitchell Parks and Minwoo Suh - has decided to replace these expensive components with much more economical alternatives as shown below:

Stirling cooler

→

Thermoelectric (Peltier) cooler

Custom Arduino

Controller Card

→

TEC Thermostat *** …

Dietary Nitrate Acutely And Markedly Increased Exhaled Nitric Oxide In A Cystic Fibrosis Case, Conor Kerley, Emma Kilbride, Peter Greally, Basil Elnazir

Articles

Airway nitric oxide (NO) is a ubiquitous signaling molecule with bronchoprotective, antiinflammatory and anti-infective roles. Cystic fibrosis (CF) is a chronic lung condition associated with deceased exhaled NO. Strategies to increase exhaled NO in CF have yielded inconsistent results. A potential new method of increasing systemic NO involves ingestion of dietary, inorganic nitrate which is reduced to nitrite and NO. We present the case of a 12 year-old, athletic male with CF who demonstrated acute but marked increases in exhaled NO following dietary nitrate consumption compared to placebo.

Severe Mortality Impact Of The 1957 Influenza Pandemic In Chile., Gerardo Chowell, Lone Simonsen, Rodrigo Fuentes, Jose Flores, Mark A Miller, Cécile Viboud

Microbiology, Immunology, and Tropical Medicine Faculty Publications

INTRODUCTION: Epidemiological studies of the 1957 influenza pandemic are scarce, particularly from lower-income settings.

METHODS: We analyzed the spatial-temporal mortality patterns of the 1957 influenza pandemic in Chile, including detailed age-specific mortality data from a large city, and investigated risk factors for severe mortality impact across regions.

RESULTS: Chile exhibited two waves of excess mortality in winter 1957 and 1959 with a cumulative excess mortality rate of 12 per 10 000, and a ~10-fold mortality difference across provinces. High excess mortality rates were associated with high baseline mortality (R(2) =41.8%; P=.02), but not with latitude (P>.7). Excess mortality rates …

Nucleoside-Diphosphate-Kinase Of P. Gingivalis Is Secreted From Epithelial Cells In The Absence Of A Leader Sequence Through A Pannexin-1 Interactome, Kalina Atanasova, Jungnam Lee, Joann Roberts, Kyulim Lee, David M. Ojcius, Özlem Yilmaz

All Dugoni School of Dentistry Faculty Articles

Nucleoside-diphosphate-kinases (NDKs) are leaderless, multifunctional enzymes. The mode(s) of NDK secretion is currently undefined, while extracellular translocation of bacterial NDKs is critical for avoidance of host pathogen clearance by opportunistic pathogens such as Porphyromonas gingivalis. P. gingivalis-NDK during infection inhibits extracellular-ATP (eATP)/P2X7-receptor mediated cell death in gingival epithelial cells (GECs) via eATP hydrolysis. Furthermore, depletion of pannexin-1-hemichannel (PNX1) coupled with P2X7-receptor blocks the infection-induced eATP release in GECs, and P. gingivalis-NDK impacts this pathway. Ultrastructural and confocal microscopy of P. gingivalis-co-cultured GECs or green-fluorescent-protein (GFP)-P. gingivalis-NDK transfected GECs revealed a perinuclear/cytoplasmic localization of NDK. eATP stimulation induced NDK recruitment to …

An Iron Detection System Determines Bacterial Swarming Initiation And Biofilm Formation, Chuan-Sheng Lin, Yu-Huan Tsai, Chih-Jung Chang, Shun-Fu Tseng, Tseng-Ru Wu, Chia-Chen Lu, Ting-Shu Wu, Jang-Jih Lu, Jim-Tong Horng, Jan Martel, David M. Ojcius, Hsin-Chih Lai, John Ding-E. Young

All Dugoni School of Dentistry Faculty Articles

Iron availability affects swarming and biofilm formation in various bacterial species. However, how bacteria sense iron and coordinate swarming and biofilm formation remains unclear. Using Serratia marcescens as a model organism, we identify here a stage-specific iron-regulatory machinery comprising a two-component system (TCS) and the TCS-regulated iron chelator 2-isocyano-6,7-dihydroxycoumarin (ICDH-Coumarin) that directly senses and modulates environmental ferric iron (Fe3+) availability to determine swarming initiation and biofilm formation. We demonstrate that the two-component system RssA-RssB (RssAB) directly senses environmental ferric iron (Fe³⁺) and transcriptionally modulates biosynthesis of flagella and the iron chelator ICDH-Coumarin whose production requires the pvc cluster. …