Life Sciences Commons^™

Protocol For An Agent-Based Model Of Recombination In Bacteria Playing A Public Goods Game, Isaiah Paolo A. Lee, Omar T. Eldakar, J. Peter Gogarten, Cheryl P. Andam

Biology Faculty Articles

Agent-based models are composed of individual agents coded for traits, such as cooperation and cheating, that interact in a virtual world based on defined rules. Here, we describe the use of an agent-based model of homologous recombination in bacteria playing a public goods game. We describe steps for software installation, setting model parameters, running and testing models, and visualization and statistical analysis. This protocol is useful in analyses of horizontal gene transfer, bacterial sociobiology, and game theory.

For complete details on the use and execution of this protocol, please refer to Lee et al.¹

Change And Stasis Of Distinct Sediment Microbiomes Across Port Everglades Inlet (Pei) And The Adjacent Coral Reefs, Lauren E. Krausfeldt, Jose V. Lopez, Catherine Bilodeau, Hyo Won Lee, Shelby L. Casali

Biology Faculty Articles

Deep water ports are human built coastal structures that by definition welcome ship traffic and disturbance. Evidence is accumulating that enhanced port activities such as dredging or deepening have negatively affected nearby natural habitats. Port Everglades Inlet (PEI) is a large active South Florida cargo port for over two million people and lies adjacent to coral reefs, dwindling mangroves, and recreational beaches. In this study, the microbial communities of PEI and adjacent reef sediments were characterized to serve as indicators for change due to dredging and assess anthropogenic influence on these sensitive ecosystems by sequencing the V4 region of 16S …

Differential Preservation Of Endogenous Human And Microbial Dna In Dental Calculus And Dentin, Allison E. Mann, Susanna Sabin, Kirsten Ziesemer, Ashild J. Vagene, Hannes Schroeder, Andrew T. Ozga, Krithivasan Sankaranarayanan, Courtney A. Hofman, James A. Fellows Yates, Domingo C. Salazar-Garcia, Bruno Frohlich, Mark Aldenderfer, Menno Hoogland, Christopher Read, George R. Milner, Anne C. Stone, Cecil M. Lewis Jr., Johannes Krause, Corinne Hofman, Kirsten I. Bos, Christina Warinner

Biology Faculty Articles

Dental calculus (calcified dental plaque) is prevalent in archaeological skeletal collections and is a rich source of oral microbiome and host-derived ancient biomolecules. Recently, it has been proposed that dental calculus may provide a more robust environment for DNA preservation than other skeletal remains, but this has not been systematically tested. In this study, shotgun-sequenced data from paired dental calculus and dentin samples from 48 globally distributed individuals are compared using a metagenomic approach. Overall, we find DNA from dental calculus is consistently more abundant and less contaminated than DNA from dentin. The majority of DNA in dental calculus is …

Is There A Link Between Aging And Microbiome Diversity In Exceptional Mammalian Longevity?, Graham M. Hughes, John Leech, Sebastien J. Puechmaille, Jose V. Lopez, Emma C. Teeling

Biology Faculty Articles

A changing microbiome has been linked to biological aging in mice and humans, suggesting a possible role of gut flora in pathogenic aging phenotypes. Many bat species have exceptional longevity given their body size and some can live up to ten times longer than expected with little signs of aging. This study explores the anal microbiome of the exceptionally long-lived Myotis myotis bat, investigating bacterial composition in both adult and juvenile bats to determine if the microbiome changes with age in a wild, long-lived non-model organism, using non-lethal sampling. The anal microbiome was sequenced using metabarcoding in more than 50 …

The Human Microbiome: An Emerging Tool In Forensics, Jarrad T. Hampton-Marcell, Jose V. Lopez, Jack A. Gilbert

Biology Faculty Articles

No abstract provided.

Otopathogenic Pseudomonas Aeruginosa Enters And Survives Inside Macrophages, Rahul Mittal, Christopher V. Lisi, Hansi Kumari, M'Hamed Grati, Patricia Blackwelder, Denise Yan, Chaitanya Jain, Kalai Mathee, Paulo H. Weckwerth, Xue Zhong Liu

Biology Faculty Articles

Otitis media (OM) is a broad term describing a group of infectious and inflammatory disorders of the middle ear. Despite antibiotic therapy, acute OM can progress to chronic suppurative otitis media (CSOM) characterized by ear drum perforation and purulent discharge. Pseudomonas aeruginosa is the most common pathogen associated with CSOM. Although, macrophages play an important role in innate immune responses but their role in the pathogenesis of P. aeruginosa-induced CSOM is not known. The objective of this study is to examine the interaction of P. aeruginosa with primary macrophages. We observed that P. aeruginosa enters and multiplies inside human …

Intrinsic Challenges In Ancient Microbiome Reconstruction Using 16s Rrna Gene Amplification, Kirsten Ziesemer, Allison Mann, Krithivasan Sankaranarayanan, Hannes Schroeder, Andrew T. Ozga, Bernd W. Brandt, Egija Zaura, Andrea Waters-Rist, Menno Hoogland, Domingo C. Salazar-Garcia, Mark Aldenderfer, Camilla Speller, Jessica Hendy, Darlene A. Weston, Sandy J. Macdonald, Gavin H. Thomas, Matthew J. Collins, Cecil M. Lewis Jr., Corinne Hofman, Christina Warinner

Biology Faculty Articles

To date, characterization of ancient oral (dental calculus) and gut (coprolite) microbiota has been primarily accomplished through a metataxonomic approach involving targeted amplification of one or more variable regions in the 16S rRNA gene. Specifically, the V3 region (E. coli341–534) of this gene has been suggested as an excellent candidate for ancient DNA amplification and microbial community reconstruction. However, in practice this metataxonomic approach often produces highly skewed taxonomic frequency data. In this study, we use non-targeted (shotgun metagenomics) sequencing methods to better understand skewed microbial profiles observed in four ancient dental calculus specimens previously analyzed by amplicon …

Toll-Like Receptor 9-Mediated Inflammation Triggers Alveolar Bone Loss In Experimental Murine Periodontitis, Paul D. Kim, Xia Xia-Juan, Katie E. Crump, Toshiharu Abe, George Hajishengallis, Sinem E. Sahingur

Biology Faculty Articles

Chronic periodontitis is a local inflammatory disease induced by a dysbiotic microbiota and leading to destruction of the tooth-supporting structures. Microbial nucleic acids are abundantly present in the periodontium, derived through release after phagocytic uptake of microbes and/or from biofilm-associated extracellular DNA. Binding of microbial DNA to its cognate receptors, such as Toll-like receptor 9 (TLR9), can trigger inflammation. In this study, we utilized TLR9 knockout (TLR9^−/−) mice and wild-type (WT) controls in a murine model of Porphyromonas gingivalis-induced periodontitis and report the first in vivo evidence that TLR9 signaling mediates the induction of periodontal bone loss.P. gingivalis-infected …

Genetic Characterization And Role In Virulence Of The Ribonucleotide Reductases Of Streptococcus Sanguinis, Delacy V. Rhodes, Katie E. Crump, Olga Makhlynets, Melanie Snyder, Xiuchun Ge, Ping Xu, Joanne Stubbe, Todd Kitten

Biology Faculty Articles

Streptococcus sanguinis is a cause of infective endocarditis and has been shown to require a manganese transporter called SsaB for virulence and O₂ tolerance. Like certain other pathogens, S. sanguinis possesses aerobic class Ib (NrdEF) and anaerobic class III (NrdDG) ribonucleotide reductases (RNRs) that perform the essential function of reducing ribonucleotides to deoxyribonucleotides. The accompanying paper (Makhlynets, O., Boal, A. K., Rhodes, D. V., Kitten, T., Rosenzweig, A. C., and Stubbe, J. (2014) J. Biol. Chem. 289, 6259–6272) indicates that in the presence of O₂, the S. sanguinis class Ib RNR self-assembles an essential diferric-tyrosyl radical (Fe …

Increased Cell Surface Free Thiols Identify Effector Cd8+ T Cells Undergoing T Cell Receptor Stimulation, Samuel Troy Pellom, Ryan D. Michalek, Katie E. Crump, P. Kent Langston, Daniel G. Juneau, Jason M. Grayson

Biology Faculty Articles

Recognition of peptide Major Histocompatibility Complexes (MHC) by the T cell receptor causes rapid production of reactive oxygen intermediates (ROI) in naïve CD8+ T cells. Because ROI such as H2O2 are membrane permeable, mechanisms must exist to prevent overoxidation of surface proteins. In this study we used fluorescently labeled conjugates of maleimide to measure the level of cell surface free thiols (CSFT) during the development, activation and differentiation of CD8+ T cells. We found that during development CSFT were higher on CD8 SP compared to CD4 SP or CD4CD8 DP T cells. After activation CSFT became elevated prior to division …

Antioxidant Treatment Regulates The Humoral Immune Response During Acute Viral Infection, Katie E. Crump, P. Kent Langston, Sujana Rajkarnikar, Jason M. Grayson

Biology Faculty Articles

Generation of reactive oxygen intermediates (ROI) following antigen receptor ligation is critical to promote cellular responses. However, the effect of antioxidant treatment on humoral immunity during a viral infection was unknown. Mice were infected with lymphocytic choriomeningitis virus (LCMV) and treated with Mn(III)tetrakis(4-benzoic acid)porphyrin chloride (MnTBAP), a superoxide dismutase mimetic, from days 0 to 8 postinfection. On day 8, at the peak of the splenic response in vehicle-treated mice, virus-specific IgM and IgG antibody-secreting cells (ASC) were decreased 22- and 457-fold in MnTBAP-treated animals. By day 38, LCMV-specific IgG ASC were decreased 5-fold in the bone marrow of drug-treated mice, …

Peroxiredoxin Ii Regulates Effector And Secondary Memory Cd8+ T Cell Responses, Ryan D. Michalek, Katie E. Crump, Ashley E. Weant, Elizabeth M. Hiltbold, Daniel G. Juneau, Eun-Yi Moon, Dae-Yeul Yu, Leslie B. Poole, Jason M. Grayson

Biology Faculty Articles

Reactive oxygen intermediates (ROI) generated in response to receptor stimulation play an important role in cellular responses. However, the effect of increased H₂O₂on an antigen-specific CD8⁺ T cell response was unknown. Following T cell receptor (TCR) stimulation, the expression and oxidation of peroxiredoxin II (PrdxII), a critical antioxidant enzyme, increased in CD8⁺ T cells. Deletion of PrdxII increased ROI, S phase entry, division, and death during in vitro division. During primary acute viral and bacterial infection, the number of effector CD8⁺ T cells in PrdxII-deficient mice was increased, while the number of memory …

Emerging Viruses In The Felidae: Shifting Paradigms, Stephen J. O'Brien, Jennifer L. Troyer, Meredith Brown, Warren E. Johnson, Agostinho Antunes, Melody E. Roelke, Jill Pecon-Slattery

Biology Faculty Articles

The domestic cat is afflicted with multiple viruses that serve as powerful models for human disease including cancers, SARS and HIV/AIDS. Cat viruses that cause these diseases have been studied for decades revealing detailed insight concerning transmission, virulence, origins and pathogenesis. Here we review recent genetic advances that have questioned traditional wisdom regarding the origins of virulent Feline infectious peritonitis (FIP) diseases, the pathogenic potential of Feline Immunodeficiency Virus (FIV) in wild non-domestic Felidae species, and the restriction of Feline Leukemia Virus (FeLV) mediated immune impairment to domestic cats rather than other Felidae species. The most recent interpretations indicate important …

Genetic Protection Against Hepatitis B Virus Conferred By Ccr5Δ32: Evidence That Ccr5 Contributes To Viral Persistence, Chloe L. Thio, Jacquie Astemborski, Arman A. Bashirova, Timothy L. Mosbruger, Spencer Greer, Mallory D. Witt, James J. Goedert, Margaret Hilgartner, Audrey Majesk, Stephen J. O'Brien, David L. Thomas, Mary Carrington

Biology Faculty Articles

Recovery from acute hepatitis B virus (HBV) infection requires a broad, vigorous T-cell response, which is enhanced in mice when chemokine receptor 5 (CCR5) is missing. To test the hypothesis that production of a nonfunctional CCR5 (CCR5Δ32 [a functionally null allele containing a 32-bp deletion]) increases the likelihood of recovery from hepatitis B in humans, we studied 526 persons from three cohorts in which one person with HBV persistence was matched to two persons who recovered from an HBV infection. Recovery or persistence was determined prior to availability of lamivudine. We determined genotypes forCCR5Δ32 …

Consistent Effects Of Tsg101 Genetic Variability On Multiple Outcomes Of Exposure To Human Immunodeficiency Virus Type 1, Arman A. Bashirova, Gabriela Bleiber, Ying Qi, Holli Hutcheson, Traci Yamashita, Randall C. Johnson, Jie Cheng, Galit Alter, James J. Goedert, Susan Buchbinder, Keith Hoots, David Vlahov, Margaret May, Frank Maldarelli, Lisa Jacobson, Stephen J. O'Brien, Amalio Telenti, Mary Carrington

Biology Faculty Articles

Tumor susceptibility gene 101 (TSG101) encodes a host cellular protein that is appropriated by human immunodeficiency virus type 1 (HIV-1) in the budding process of viral particles from infected cells. Variation in the coding or noncoding regions of the gene could potentially affect the degree of TSG101-mediated release of viral particles. While the coding regions of the gene were found to lack nonsynonymous variants, two polymorphic sites in the TSG101 5' area were identified that were associated with the rate of AIDS progression among Caucasians. These single-nucleotide polymorphisms (SNPs), located at positions -183 and +181 relative to the …

Seroprevalence And Genomic Divergence Of Circulating Strains Of Feline Immunodeficiency Virus Among Felidae And Hyaenidae Species, Jennifer L. Troyer, Jill Pecon-Slattery, Melody E. Roelke, Warren E. Johnson, Sue Vandewoude, Nuria Vazquez-Salat, Meredith Brown, Laurence Frank, Rosie Woodroffe, Christiaan Winterbach, Hanlie Winterbach, Graham Hemson, Mitchell Bush, Kathleen A. Alexander, Eloy Revilla, Stephen J. O'Brien

Biology Faculty Articles

Feline immunodeficiency virus (FIV) infects numerous wild and domestic feline species and is closely related to human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). Species-specific strains of FIV have been described for domestic cat (Felis catus), puma (Puma concolor), lion (Panthera leo), leopard (Panthera pardus), and Pallas' cat (Otocolobus manul). Here, we employ a three-antigen Western blot screening (domestic cat, puma, and lion FIV antigens) and PCR analysis to survey worldwide prevalence, distribution, and genomic differentiation of FIV based on 3,055 specimens from 35 Felidae and 3 Hyaenidae species. …

Mannose Binding Lectin Genotypes Influence Recovery From Hepatitis B Virus Infection, Chloe L. Thio, Timothy L. Mosbruger, Jacquie Astemborski, Spencer Greer, Gregory D. Kirk, Stephen J. O'Brien, David L. Thomas

Biology Faculty Articles

Mannose binding lectin (MBL) is a central component of the innate immune response and thus may be important for determining hepatitis B virus (HBV) persistence. Since single-nucleotide polymorphisms (SNPs) in the gene encoding MBL (mbl2) alter the level of functional MBL, we hypothesized that mbl2 genotypes are a determinant of HBV persistence or recovery from viral infection. We tested this hypothesis by using a nested case control design with 189 persons with HBV persistence matched to 338 individuals who had naturally recovered from HBV infection. We determined genotypes of two promoter and three exon 1 SNPs in mbl2 …

Insertional Polymorphisms Of Endogenous Feline Leukemia Viruses, Alfred L. Roca, William G. Nash, Joan C. Menninger, William J. Murphy, Stephen J. O'Brien

Biology Faculty Articles

The number, chromosomal distribution, and insertional polymorphisms of endogenous feline leukemia viruses (enFeLVs) were determined in four domestic cats (Burmese, Egyptian Mau, Persian, and nonbreed) using fluorescent in situ hybridization and radiation hybrid mapping. Twenty-nine distinct enFeLV loci were detected across 12 of the 18 autosomes. Each cat carried enFeLV at only 9 to 16 of the loci, and many loci were heterozygous for presence of the provirus. Thus, an average of 19 autosomal copies of enFeLV were present per cat diploid genome. Only five of the autosomal enFeLV sites were present in all four cats, and at only one …

Association Of Dc-Sign Promoter Polymorphism With Increased Risk For Parenteral, But Not Mucosal, Acquisition Of Human Immunodeficiency Virus Type 1 Infection, Maureen P. Martin, Michael M. Lederman, Holli B. Hutcheson, James J. Goedert, George W. Nelson, Yvette Van Kooyk, Roger Detels, Susan Buchbinder, Keith Hoots, David Vlahov, Stephen J. O'Brien, Mary Carrington

Biology Faculty Articles

There is considerable debate about the fundamental mechanisms that underlie and restrict acquisition of human immunodeficiency virus type 1 (HIV-1) infection. In light of recent studies demonstrating the ability of C type lectins to facilitate infection with HIV-1, we explored the potential relationship between polymorphisms in the DC-SIGN promoter and risk for acquisition of HIV-1 according to route of infection. Using samples obtained from 1,611 European-American participants at risk for parenteral (n = 713) or mucosal (n = 898) infection, we identified single-nucleotide polymorphisms in the DC-SIGN promoter using single-strand conformation polymorphism. Individuals at risk for parenterally acquired …

Apobec3g Genetic Variants And Their Influence On The Progression To Aids, Ping An, Gabriela Bleiber, Priya Duggal, George Nelson, Margaret May, Bastien Mangeat, Irene Alobwede, Didier Trono, David Vlahov, Sharyne Donfield, James J. Goedert, John Phair, Susan Buchbinder, Stephen J. O'Brien, Amalio Telenti, Cheryl Winkler

Biology Faculty Articles

The cytosine deaminase APOBEC3G, in the absence of the human immunodeficiency virus type 1 (HIV-1) accessory gene HIV-1 viral infectivity factor (vif), inhibits viral replication by introducing G→A hypermutation in the newly synthesized HIV-1 DNA negative strand. We tested the hypothesis that genetic variants of APOBEC3G may modify HIV-1 transmission and disease progression. Single nucleotide polymorphisms were identified in the promoter region (three), introns (two), and exons (two). Genotypes were determined for 3,073 study participants enrolled in six HIV-AIDS prospective cohorts. One codon-changing variant, H186R in exon 4, was polymorphic in African Americans (AA) (f < 37%) and rare in European Americans (f < 3%) or Europeans (f …