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Medical Microbiology

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Articles 31 - 60 of 64

Full-Text Articles in Biochemical Phenomena, Metabolism, and Nutrition

The Trait Repertoire Enabling Cyanobacteria To Bloom Assessed Through Comparative Genomic Complexity And Metatranscriptomics, Huansheng Cao, Yohei Shimura, Morgan M. Steffen, Zhou Yang, Jingrang Lu, Allen Joel, Landon Jenkins, Masanobu Kawachi, Yanbin Yin, Ferran Garcia-Pichel May 2020

The Trait Repertoire Enabling Cyanobacteria To Bloom Assessed Through Comparative Genomic Complexity And Metatranscriptomics, Huansheng Cao, Yohei Shimura, Morgan M. Steffen, Zhou Yang, Jingrang Lu, Allen Joel, Landon Jenkins, Masanobu Kawachi, Yanbin Yin, Ferran Garcia-Pichel

Food for Health: Publications

Water bloom development due to eutrophication constitutes a case of niche specialization among planktonic cyanobacteria, but the genomic repertoire allowing bloom formation in only some species has not been fully characterized. We posited that the habitat relevance of a trait begets its underlying genomic complexity, so that traits within the repertoire would be differentially more complex in species successfully thriving in that habitat than in close species that cannot. To test this for the case of bloom-forming cyanobacteria, we curated 17 potentially relevant query metabolic pathways and five core pathways selected according to existing ecophysiological literature. The available 113 genomes …

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How Immune T-Cell Augmentation Can Help Prevent Covid-19: A Possible Nutritional Solution Using Ketogenic Lifestyle, Ravi K. Kamepalli Md,Fidsa,Cwsp Apr 2020

How Immune T-Cell Augmentation Can Help Prevent Covid-19: A Possible Nutritional Solution Using Ketogenic Lifestyle, Ravi K. Kamepalli Md,Fidsa,Cwsp

The University of Louisville Journal of Respiratory Infections

No abstract provided.

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Alteration Of The Gut Microbiome In Normal And Overweight School Children From Selangor With Lactobacillus Fermented Milk Administration, Narcisse Joseph, Jonathan B. Clayton, Susan L. Hoops, Carter A. Linhardt, Amalia Mohd Hashim, Barakatun Nisak Mohd Yusof, Suresh Kumar, Syafinaz Amin Nordin Jan 2020

Alteration Of The Gut Microbiome In Normal And Overweight School Children From Selangor With Lactobacillus Fermented Milk Administration, Narcisse Joseph, Jonathan B. Clayton, Susan L. Hoops, Carter A. Linhardt, Amalia Mohd Hashim, Barakatun Nisak Mohd Yusof, Suresh Kumar, Syafinaz Amin Nordin

Food for Health: Publications

Childhood obesity is a serious public health problem worldwide. Perturbations in the gut microbiota composition have been associated with the development of obesity in both children and adults. Probiotics, on the other hand, are proven to restore the composition of the gut microbiome which helps reduce the development of obesity. However, data on the effect of probiotics on gut microbiota and its association with childhood obesity is limited. This study aims to determine the effect of probiotics supplement intervention on gut microbiota profiles in obese and normal-weight children. A total of 37 children, 17 normal weight, and 20 overweight school …

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Stool Microbiome, Ph And Short/Branched Chain Fatty Acids In Infants Receiving Extensively Hydrolyzed Formula, Amino Acid Formula, Or Human Milk Through Two Months Of Age, Car Reen Kok, Bradford Brabec, Maciej Chichlowski, Cheryl L. Harris, Nancy Moore, Jennifer L. Wampler, Jon Vanderhoof, Devin Rose, Robert Hutkins Jan 2020

Stool Microbiome, Ph And Short/Branched Chain Fatty Acids In Infants Receiving Extensively Hydrolyzed Formula, Amino Acid Formula, Or Human Milk Through Two Months Of Age, Car Reen Kok, Bradford Brabec, Maciej Chichlowski, Cheryl L. Harris, Nancy Moore, Jennifer L. Wampler, Jon Vanderhoof, Devin Rose, Robert Hutkins

Food for Health: Publications

CRISPR–Cas is an anti-viral mechanism of prokaryotes that has been widely adopted for genome editing. To make CRISPR–Cas genome editing more controllable and safer to use, anti-CRISPR proteins have been recently exploited to prevent excessive/prolonged Cas nuclease cleavage. Anti-CRISPR (Acr) proteins are encoded by (pro)phages/(pro)viruses, and have the ability to inhibit their host’s CRISPR–Cas systems. We have built an online database AcrDB (http://bcb.unl.edu/AcrDB) by scanning ∼19 000 genomes of prokaryotes and viruses with AcrFinder, a recently developed AcrAca (Acr-associated regulator) operon prediction program. Proteins in Acr-Aca operons were further processed by two machine learning-based programs (AcRanker and PaCRISPR) to obtain …

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An In Vitro Enrichment Strategy For Formulating Synergistic Synbiotics, Car Reen Kok, David Fabian Gomez Quintero, Clement Niyirora, Devin Rose, Amanda Li, Robert Hutkins Aug 2019

An In Vitro Enrichment Strategy For Formulating Synergistic Synbiotics, Car Reen Kok, David Fabian Gomez Quintero, Clement Niyirora, Devin Rose, Amanda Li, Robert Hutkins

Food for Health: Publications

ABSTRACT Research on the role of diet on gut and systemic health has led to considerable interest toward identifying novel therapeutic modulators of the gut microbiome, including the use of prebiotics and probiotics. However, various host responses have often been reported among many clinical trials. This is in part due to competitive exclusion as a result of the absence of ecological niches as well as host mediated constraints via colonization resistance. In this research, we developed a novel in vitro enrichment (IVE) method for isolating autochthonous strains that can function as synergistic synbiotics and overcome these constraints. The method relied …

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Experimental Evaluation Of The Importance Of Colonization History In Early-Life Gut Microbiota Assembly, Inés Martínez, Maria X. Maldonado-Gomez, João Carlos Gomes-Neto, Hatem Kittana, Hua Ding, Robert J. Schmaltz, Payal Joglekar, Roberto Jiménez Cardona, Nathan L Marsteller, Steven W. Kembel, Andrew K. Benson, Daniel A. Peterson, Amanda Ramer-Tait, Jens C. Walter Sep 2018

Experimental Evaluation Of The Importance Of Colonization History In Early-Life Gut Microbiota Assembly, Inés Martínez, Maria X. Maldonado-Gomez, João Carlos Gomes-Neto, Hatem Kittana, Hua Ding, Robert J. Schmaltz, Payal Joglekar, Roberto Jiménez Cardona, Nathan L Marsteller, Steven W. Kembel, Andrew K. Benson, Daniel A. Peterson, Amanda Ramer-Tait, Jens C. Walter

Department of Food Science and Technology: Faculty Publications

The factors that govern assembly of the gut microbiota are insufficiently understood. Here, we test the hypothesis that inter-individual microbiota variation can arise solely from differences in the order and timing by which the gut is colonized early in life. Experiments in which mice were inoculated in sequence either with two complex seed communities or a cocktail of four bacterial strains and a seed community revealed that colonization order influenced both the outcome of community assembly and the ecological success of individual colonizers. Historical contingency and priority effects also occurred in Rag1-/- mice, suggesting that the adaptive immune system …

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Considerations For Best Practices In Studies Of Fiber Or Other Dietary Components And The Intestinal Microbiome, David M. Klurfeld, Cindy D. Davis, Robert W. Karp, Emma Allen-Vercoe, Eugene B. Chang, Benoit Chassaing, George C. Fahey Jr, Bruce R. Hamaker, Hannah D. Holscher, Johanna W. Lampe, Andre Marette, Eric Martens, Stephen J. O'Keefe, Devin J. Rose, Maria Saarela, Barbara O. Schneeman, Joanne L. Slavin, Justin L. Sonnenburg, Kelly S. Swanson, Gary D. Wu, Christopher J. Lynch Aug 2018

Considerations For Best Practices In Studies Of Fiber Or Other Dietary Components And The Intestinal Microbiome, David M. Klurfeld, Cindy D. Davis, Robert W. Karp, Emma Allen-Vercoe, Eugene B. Chang, Benoit Chassaing, George C. Fahey Jr, Bruce R. Hamaker, Hannah D. Holscher, Johanna W. Lampe, Andre Marette, Eric Martens, Stephen J. O'Keefe, Devin J. Rose, Maria Saarela, Barbara O. Schneeman, Joanne L. Slavin, Justin L. Sonnenburg, Kelly S. Swanson, Gary D. Wu, Christopher J. Lynch

Food for Health: Publications

Considerations for best practices in studies of fiber or other dietary components and the intestinal microbiome. Am J Physiol Endocrinol Metab 315: E1087–E1097, 2018. First published August 21, 2018; doi:10.1152/ajpendo.00058.2018.—A 2-day workshop organized by the National Institutes of Health and U.S. Department of Agriculture included 16 presentations focused on the role of diet in alterations of the gastrointestinal microbiome, primarily that of the colon. Although thousands of research projects have been funded by U.S. federal agencies to study the intestinal microbiome of humans and a variety of animal models, only a minority addresses dietary effects, and a small subset is …

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Structure-Based Design Of Hepatitis C Virus Vaccines That Elicit Neutralizing Antibody Responses To A Conserved Epitope, Brian G. Pierce, Elisabeth N. Boucher, Kurt H. Piepenbrink, Monir Ejemal, Chelsea A. Rapp, William D. Thomas Jr, Eric J. Sundberg, Zhiping Weng, Yang Wang Aug 2017

Structure-Based Design Of Hepatitis C Virus Vaccines That Elicit Neutralizing Antibody Responses To A Conserved Epitope, Brian G. Pierce, Elisabeth N. Boucher, Kurt H. Piepenbrink, Monir Ejemal, Chelsea A. Rapp, William D. Thomas Jr, Eric J. Sundberg, Zhiping Weng, Yang Wang

Food for Health: Publications

Despite recent advances in therapeutic options, hepatitis C virus (HCV) remains a severe global disease burden, and a vaccine can substantially reduce its incidence. Due to its extremely high sequence variability, HCV can readily escape the immune response; thus, an effective vaccine must target conserved, functionally important epitopes. Using the structure of a broadly neutralizing antibody in complex with a conserved linear epitope from the HCV E2 envelope glycoprotein (residues 412 to 423; epitope I), we performed structure-based design of immunogens to induce antibody responses to this epitope. This resulted in epitope-based immunogens based on a cyclic defensin protein, as …

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How An Alloreactive T-Cell Receptor Achieves Peptide And Mhc Specificity, Yuan Wang, Nishant K. Singh, Timothy T. Spear, Lance M. Hellman, Kurt H. Piepenbrink, Rachel H. Mcmahan, Hugo R. Rosen, Craig W. Vander Kooi, Michael I. Nishimura, Brian M. Baker May 2017

How An Alloreactive T-Cell Receptor Achieves Peptide And Mhc Specificity, Yuan Wang, Nishant K. Singh, Timothy T. Spear, Lance M. Hellman, Kurt H. Piepenbrink, Rachel H. Mcmahan, Hugo R. Rosen, Craig W. Vander Kooi, Michael I. Nishimura, Brian M. Baker

Food for Health: Publications

T-cell receptor (TCR) allorecognition is often presumed to be relatively nonspecific, attributable to either a TCR focus on exposed major histocompatibility complex (MHC) polymorphisms or the degenerate recognition of allopeptides. However, paradoxically, alloreactivity can proceed with high peptide and MHC specificity. Although the underlying mechanisms remain unclear, the existence of highly specific alloreactive TCRs has led to their use as immunotherapeutics that can circumvent central tolerance and limit graft-versus-host disease. Here, we show how an alloreactive TCR achieves peptide and MHC specificity. The HCV1406 TCR was cloned from T cells that expanded when a hepatitis C virus (HCV)-infected HLA-A2− individual …

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The Host Microbiome Regulates And Maintains Human Health: A Primer And Perspective For Non-Microbiologists, Sunil Thomas, Jacques Izard, Emily Walsh, Kristen Batich, Pakawat Chongsathidkiet, Gerard Clarke, David A. Sela, Alexander J. Muller, James M. Mullin, Korin Albert, John P. Gilligan, Katherine Diguilio, Rima Dilbarova, Walker Alexander, George P. Prendergast Mar 2017

The Host Microbiome Regulates And Maintains Human Health: A Primer And Perspective For Non-Microbiologists, Sunil Thomas, Jacques Izard, Emily Walsh, Kristen Batich, Pakawat Chongsathidkiet, Gerard Clarke, David A. Sela, Alexander J. Muller, James M. Mullin, Korin Albert, John P. Gilligan, Katherine Diguilio, Rima Dilbarova, Walker Alexander, George P. Prendergast

Department of Food Science and Technology: Faculty Publications

Humans consider themselves discrete autonomous organisms, but recent research is rapidly strengthening the appreciation that associated microorganisms make essential contributions to human health and well being. Each person is inhabited and also surrounded by his/her own signature microbial cloud. A low diversity of microorganisms is associated with a plethora of diseases, including allergy, diabetes, obesity, arthritis, inflammatory bowel diseases, and even neuropsychiatric disorders. Thus, an interaction of microorganisms with the host immune system is required for a healthy body. Exposure to microorganisms from the moment we are born and appropriate microbiome assembly during childhood are essential for establishing an active …

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Motility And Adhesion Through Type Iv Pili In Gram-Positive Bacteria, Kurt H. Piepenbrink, Eric J. Sundberg Dec 2016

Motility And Adhesion Through Type Iv Pili In Gram-Positive Bacteria, Kurt H. Piepenbrink, Eric J. Sundberg

Food for Health: Publications

Type IV pili are hair-like bacterial surface appendages that play a role in diverse processes such as cellular adhesion, colonization, twitching motility, biofilm formation, and horizontal gene transfer. These extracellular fibers are composed exclusively or primarily of many copies of one or more pilin proteins, tightly packed in a helix so that the highly hydrophobic amino-terminus of the pilin is buried in the pilus core. Type IV pili have been characterized extensively in Gram-negative bacteria, and recent advances in high-throughput genomic sequencing have revealed that they are also widespread in Gram-positive bacteria. Here, we review the current state of knowledge …

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A Generalized Framework For Computational Design And Mutational Scanning Of T-Cell Receptor Binding Interfaces, Timothy P. Riley, Cory M. Ayres, Lance M. Hellman, Nishant K. Singh, Michael Cosiano, Jennifer M. Cimons, Michael J. Anderson, Kurt H. Piepenbrink, Brian G. Pierce, Zhiping Weng, Brian M. Baker Nov 2016

A Generalized Framework For Computational Design And Mutational Scanning Of T-Cell Receptor Binding Interfaces, Timothy P. Riley, Cory M. Ayres, Lance M. Hellman, Nishant K. Singh, Michael Cosiano, Jennifer M. Cimons, Michael J. Anderson, Kurt H. Piepenbrink, Brian G. Pierce, Zhiping Weng, Brian M. Baker

Food for Health: Publications

T-cell receptors (TCRs) have emerged as a new class of therapeutics, most prominently for cancer where they are the key components of new cellular therapies as well as soluble biologics. Many studies have generated high affinity TCRs in order to enhance sensitivity. Recent outcomes, however, have suggested that fine manipulation of TCR binding, with an emphasis on specificity may be more valuable than large affinity increments. Structure-guided design is ideally suited for this role, and here we studied the generality of structure-guided design as applied to TCRs. We found that a previous approach, which successfully optimized the binding of a …

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Structural Diversity In The Type Iv Pili Of Multidrug-Resistant Acinetobacter, Kurt H. Piepenbrink, Erik Lillehoj, Christian M. Harding, Jason W. Labonte, Xiaotong Zuo, Chelsea A. Rapp, Robert S. Munson Jr, Simeon E. Goldblum, Mario F. Feldman, Jeffrey J. Gray, Eric J. Sundberg Sep 2016

Structural Diversity In The Type Iv Pili Of Multidrug-Resistant Acinetobacter, Kurt H. Piepenbrink, Erik Lillehoj, Christian M. Harding, Jason W. Labonte, Xiaotong Zuo, Chelsea A. Rapp, Robert S. Munson Jr, Simeon E. Goldblum, Mario F. Feldman, Jeffrey J. Gray, Eric J. Sundberg

Food for Health: Publications

Acinetobacter baumannii is a Gram-negative coccobacillus found primarily in hospital settings that has recently emerged as a source of hospital-acquired infections. A. baumannii expresses a variety of virulence factors, including type IV pili, bacterial extracellular appendages often essential for attachment to host cells. Here, we report the high resolution structures of the major pilin subunit, PilA, from three Acinetobacter strains, demonstrating thatA. baumannii subsets produce morphologically distinct type IV pilin glycoproteins. We examine the consequences of this heterogeneity for protein folding and assembly as well as host-cell adhesion by Acinetobacter. Comparisons of genomic and structural data with pilin proteins from …

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The Neu1-Selective Sialidase Inhibitor, C9- Butyl-Amide-Dana, Blocks Sialidase Activity And Neu1-Mediated Bioactivities In Human Lung In Vitro And Murine Lung In Vivo, Sang W. Hyun, Anguo Liu, Zhenguo Liu, Alan S. Cross, Avelino C. Verceles, Sadagopan Magesh, Yadagiri Kommagalla, Chandrababunaidu Kona, Hiromune Ando, Irina G. Luzina, Sergei P. Atamas, Kurt H. Piepenbrink, Eric J. Sundberg, Wei Guang, Hideharu Ishida, Erik P. Lillehoj, Simeon E. Goldblum Sep 2016

The Neu1-Selective Sialidase Inhibitor, C9- Butyl-Amide-Dana, Blocks Sialidase Activity And Neu1-Mediated Bioactivities In Human Lung In Vitro And Murine Lung In Vivo, Sang W. Hyun, Anguo Liu, Zhenguo Liu, Alan S. Cross, Avelino C. Verceles, Sadagopan Magesh, Yadagiri Kommagalla, Chandrababunaidu Kona, Hiromune Ando, Irina G. Luzina, Sergei P. Atamas, Kurt H. Piepenbrink, Eric J. Sundberg, Wei Guang, Hideharu Ishida, Erik P. Lillehoj, Simeon E. Goldblum

Food for Health: Publications

Neuraminidase-1 (NEU1) is the predominant sialidase expressed in human airway epithelia and lung microvascular endothelia where it mediates multiple biological processes. We tested whether the NEU1-selective sialidase inhibitor, C9-butyl-amide-2-deoxy-2,3-dehydro-Nacetylneuraminic acid (C9-BA-DANA), inhibits one or more established NEU1-mediated bioactivities in human lung cells. We established the IC50 values of C9-BA-DANA for total sialidase activity in human airway epithelia, lung microvascular endothelia and lung fibroblasts to be 3.74 µM, 13.0 µM and 4.82 µM, respectively. In human airway epithelia, C9-BA-DANA dose-dependently inhibited flagellin-induced, NEU1-mediated mucin-1 ectodomain desialylation, adhesiveness for Pseudomonas aeruginosa and shedding. In lung microvascular endothelia, C9-BA-DANA reversed NEU1-driven restraint of …

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Type Iv Pili Promote Early Biofilm Formation By Clostridium Difficile, Grace A. Maldarelli, Kurt H. Piepenbrink, Alison J. Scott, Jeffrey A. Freiberg, Yang Song, Yvonee Achermann, Robert K. Ernst, Mark E. Shirtliff, Eric J. Sundberg, Michael S. Donnenberg, Erik C. Von Rosenvinge Jun 2016

Type Iv Pili Promote Early Biofilm Formation By Clostridium Difficile, Grace A. Maldarelli, Kurt H. Piepenbrink, Alison J. Scott, Jeffrey A. Freiberg, Yang Song, Yvonee Achermann, Robert K. Ernst, Mark E. Shirtliff, Eric J. Sundberg, Michael S. Donnenberg, Erik C. Von Rosenvinge

Food for Health: Publications

Increasing morbidity and mortality from Clostridium difficile infection (CDI) present an enormous challenge to healthcare systems. Clostridium difficile express type IV pili (T4P), but their function remains unclear. Many chronic and recurrent bacterial infections result from biofilms, surface-associated bacterial communities embedded in an extracellular matrix. CDI may be biofilm mediated; T4P are important for biofilm formation in a number of organisms. We evaluate the role of T4P in C. difficile biofilm formation using RNA sequencing, mutagenesis and complementation of the gene encoding the major pilin pilA1, and microscopy. RNA sequencing demonstrates that, in comparison to other growth phenotypes, C. difficile …

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Structural And Evolutionary Analyses Show Unique Stabilization Strategies In The Type Iv Pili Of Clostridium Difficile, Kurt H. Piepenbrink, Grace A. Maldarelli, Claudia F. Martinez De La Pena, Tanis C. Dingle, George L. Mulvey, Amanda Lee, Erik Von Rosenvinge, Glen D. Armstrong, Michael S. Donnenberg, Eric J. Sundberg Feb 2016

Structural And Evolutionary Analyses Show Unique Stabilization Strategies In The Type Iv Pili Of Clostridium Difficile, Kurt H. Piepenbrink, Grace A. Maldarelli, Claudia F. Martinez De La Pena, Tanis C. Dingle, George L. Mulvey, Amanda Lee, Erik Von Rosenvinge, Glen D. Armstrong, Michael S. Donnenberg, Eric J. Sundberg

Food for Health: Publications

Type IV pili are produced by many pathogenic Gram-negative bacteria and are important for processes as diverse as twitching motility, biofilm formation, cellular adhesion and horizontal gene transfer. However, many Gram-positive species, including C. difficile, also produce Type IV pili. Here, we identify the major subunit of the Type IV pili of C. difficile, PilA1, and describe multiple three-dimensional structures of PilA1, demonstrating the diversity found in three strains of C. difficile. We also model the incorporation of both PilA1 and a minor pilin, PilJ, into the pilus fiber. Although PilA1 contains no cysteine residues, and therefore cannot form the …

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Manipulation Of The Microbiome And Its Impact On Functional Recovery Following Ischemic Stroke, Michal Jandzinski May 2015

Manipulation Of The Microbiome And Its Impact On Functional Recovery Following Ischemic Stroke, Michal Jandzinski

Honors Scholar Theses

Each year, nearly 800,000 individuals residing in the United States will have a stroke. Of these, about 130,000 cases will prove fatal while many of the survivors will be forced to live with disability for the remainder of their lives. Out of all strokes over 87% are ischemic strokes. The widespread incidence of this debilitating condition costs the United States an estimated $36.5 billion dollars every single year. Despite this, clinicians are armed with very little to combat the disease. Recent research developments have brought about the rise in awareness about the importance of the microbiome, the various gut flora …

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Plasticity In The Contribution Of T Cell Receptor Variable Region Residues To Binding Of Peptide-Hla-A2 Complexes, Sheena N. Smith, Daniel Sommermeyer, Kurt H. Piepenbrink, Sydney J. Blevins, Helga Bernhard, Wolfgang Uckert, Brian M. Baker, David M. Kranz Nov 2014

Plasticity In The Contribution Of T Cell Receptor Variable Region Residues To Binding Of Peptide-Hla-A2 Complexes, Sheena N. Smith, Daniel Sommermeyer, Kurt H. Piepenbrink, Sydney J. Blevins, Helga Bernhard, Wolfgang Uckert, Brian M. Baker, David M. Kranz

Food for Health: Publications

One hypothesis to account for MHC-restriction by T cell receptors (TCRs) holds that there are several evolutionary-conserved residues in TCR variable regions that contact MHC. While this ‘germline-codon’ hypothesis is supported by various lines of evidence, it has been difficult to test. The difficulty stems in part from the fact that TCRs exhibit low affinities for pep/MHC, thus limiting the range of binding energies that can be assigned to these key interactions using mutational analyses. To measure the magnitude of binding energies involved, here we used high affinity TCRs engineered by mutagenesis of CDR3. The TCRs included a high-affinity, MART-1/ …

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A Novel Multivalent, Single-Domain Antibody Targeting Tcda And Tcdb Prevents Fulminant Clostridium Difficile Infection In Mice, Zhiyong Yang, Diane Schmidt, Weilong Liu, Shan Li, Lianfa Shi, Jinliang Sheng, Kevin Chen, Hua Yu, Jacqueline M. Tremblay, Xinhua Chen, Kurt H. Piepenbrink, Eric J. Sundberg, Ciaran P. Kelly, Guang Bai, Charles B. Shoemaker, Hanping Feng Mar 2014

A Novel Multivalent, Single-Domain Antibody Targeting Tcda And Tcdb Prevents Fulminant Clostridium Difficile Infection In Mice, Zhiyong Yang, Diane Schmidt, Weilong Liu, Shan Li, Lianfa Shi, Jinliang Sheng, Kevin Chen, Hua Yu, Jacqueline M. Tremblay, Xinhua Chen, Kurt H. Piepenbrink, Eric J. Sundberg, Ciaran P. Kelly, Guang Bai, Charles B. Shoemaker, Hanping Feng

Food for Health: Publications

The incidence of Clostridium difficile infection (CDI) and associated mortality have increased rapidly worldwide in recent years. Therefore, it is critical to develop new therapies for CDI. In this study, we generated a novel, potently neutralizing, tetravalent, and bispecific antibody composed of 2 heavy-chain-only VH (VHH) binding domains against both TcdA and TcdB (designated “ABA”) that reverses fulminant CDI in mice infected with an epidemic 027 strain after a single injection of the antibody. We demonstrated that ABA bound to both toxins simultaneously and displayed a significantly enhanced neutralizing activity both in vitro and in vivo. Additionally, …

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Recruitment Of Tlr Adapter Trif To Tlr4 Signaling Complex Is Mediated By The Second Helical Region Of Trif Tir Domain, Wenji Piao, Lisa W. Ru, Kurt H. Piepenbrink, Eric J. Sundberg, Stefanie N. Vogel, Vladimir Y. Toshchakov Oct 2013

Recruitment Of Tlr Adapter Trif To Tlr4 Signaling Complex Is Mediated By The Second Helical Region Of Trif Tir Domain, Wenji Piao, Lisa W. Ru, Kurt H. Piepenbrink, Eric J. Sundberg, Stefanie N. Vogel, Vladimir Y. Toshchakov

Food for Health: Publications

Toll/IL-1R resistance (TIR) domain–containing adapter-inducing IFN-β (TRIF) is a Toll-like receptor (TLR) adapter that mediates MyD88-independent induction of type I interferons through activation of IFN regulatory factor 3 and NFκB. We have examined peptides derived from the TRIF TIR domain for ability to inhibit TLR4. In addition to a previously identified BB loop peptide (TF4), a peptide derived from putative helix B of TRIF TIR (TF5) strongly inhibits LPS-induced cytokine and MAPK activation in wild-type cells. TF5 failed to inhibit LPS-induced cytokine and kinase activation in TRIF-deficient immortalized bone-marrow–derived macrophage, but was fully inhibitory in MyD88 knockout cells. TF5 does …

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Methods For Quantifying T Cell Receptor Binding Affinities And Thermodynamics, Kurt H. Piepenbrink, Brian E. Gloor, Kathryn M. Armstrong, Brian M. Baker Jun 2013

Methods For Quantifying T Cell Receptor Binding Affinities And Thermodynamics, Kurt H. Piepenbrink, Brian E. Gloor, Kathryn M. Armstrong, Brian M. Baker

Food for Health: Publications

αβ T cell receptors (TCRs) recognize peptide antigens bound and presented by class I or class II major histocompatibility complex (MHC) proteins. Recognition of a peptide/MHC complex is required for initiation and propagation of a cellular immune response, as well as the development and maintenance of the T cell repertoire. Here we discuss methods to quantify the affinities and thermodynamics of interactions between soluble ectodomains of TCRs and their peptide/MHC ligands, focusing on titration calorimetry, surface plasmon resonance, and fluorescence anisotropy. As TCRs typically bind ligand with weak-to-moderate affinities, we focus the discussion on means to enhance the accuracy and …

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Holobiont Nutrition: Considering The Role Of The Gastrointestinal Microbiota In The Health Benefits Of Whole Grains, Jens Walter, Ines Martinez, Devin J. Rose Apr 2013

Holobiont Nutrition: Considering The Role Of The Gastrointestinal Microbiota In The Health Benefits Of Whole Grains, Jens Walter, Ines Martinez, Devin J. Rose

Food for Health: Publications

Intake of whole grains and other food products high in dietary fiber have long been linked to the prevention of chronic diseases associated with inflammation. A contribution of the gastrointestinal microbiota to these effects has been suggested, but little is known on how whole grains interact with gut bacteria. We have recently published the first human trial that made use of next-generation sequencing to determine the effect of whole grains (whole grain barley, brown rice or a mixture of the two) on fecal microbiota structure and tested for associations between the gut microbiota and blood markers of inflammation, glucose and …

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Gut Microbiome Composition Is Linked To Whole Grain-Induced Immunological Improvements, Ines Martinez, James M. Lattimer, Kelcie L. Hubach, Jennifer A. Case, Junyi Yang, Casey G. Weber, Julie A. Louk, Devin J. Rose, Gayaneh Kyureghian, Daniel A. Peterson, Mark D. Haub, Jens Walter Aug 2012

Gut Microbiome Composition Is Linked To Whole Grain-Induced Immunological Improvements, Ines Martinez, James M. Lattimer, Kelcie L. Hubach, Jennifer A. Case, Junyi Yang, Casey G. Weber, Julie A. Louk, Devin J. Rose, Gayaneh Kyureghian, Daniel A. Peterson, Mark D. Haub, Jens Walter

Food for Health: Publications

The involvement of the gut microbiota in metabolic disorders, and the ability of whole grains to affect both host metabolism and gut microbial ecology, suggest that some benefits of whole grains are mediated through their effects on the gut microbiome. Nutritional studies that assess the effect of whole grains on both the gut microbiome and human physiology are needed. We conducted a randomized cross-over trial with four-week treatments in which 28 healthy humans consumed a daily dose of 60 g of whole-grain barley (WGB), brown rice (BR), or an equal mixture of the two (BR+WGB), and characterized their impact on …

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Single-Chain Vαvβ T Cell Receptors Function Without Mispairing With Endogenous Tcr Chains1, David H. Aggen, Adam S. Chervin, Thomas M. Schmitt, Boris Engels, Jennifer D. Stone, Sarah A. Richman, Kurt H. Piepenbrink, Brian M. Baker, Philip D. Greenberg, Hans Schreiber, David M. Kranz Apr 2012

Single-Chain Vαvβ T Cell Receptors Function Without Mispairing With Endogenous Tcr Chains1, David H. Aggen, Adam S. Chervin, Thomas M. Schmitt, Boris Engels, Jennifer D. Stone, Sarah A. Richman, Kurt H. Piepenbrink, Brian M. Baker, Philip D. Greenberg, Hans Schreiber, David M. Kranz

Food for Health: Publications

Transduction of exogenous T cell receptor (TCR) genes into patients’ activated peripheral blood T cells is a potent strategy to generate large numbers of specific T cells for adoptive therapy of cancer and viral diseases. However, the remarkable clinical promise of this powerful approach is still being overshadowed by a serious potential consequence: mispairing of the exogenous TCR chains with endogenous TCR chains. These “mixed” heterodimers can generate new specificities that result in graft-versus-host reactions. Engineering TCR constant regions of the exogenous chains with a cysteine promotes proper pairing and reduces the mispairing, but, as we show here, does not …

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Conformational Melding Permits A Conserved Binding Geometry In Tcr Recognition Of Foreign And Self Molecular Mimics, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Brian M. Baker Mar 2012

Conformational Melding Permits A Conserved Binding Geometry In Tcr Recognition Of Foreign And Self Molecular Mimics, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Brian M. Baker

Food for Health: Publications

Molecular mimicry between foreign and self antigens is a mechanism of T cell receptor cross reactivity and is thought to contribute to the development of autoimmunity. The αβ TCR A6 recognizes the foreign antigen Tax from the virus HTLV-1 when presented by the class I MHC HLA-A2. In a possible link with the autoimmune disease HAM/TSP, A6 also recognizes a self peptide from the neuronal protein HuD in the context of HLA-A2. We found here that the complexes of the HuD and Tax epitopes with HLA-A2 are close but imperfect structural mimics, and that in contrast with other recent structures …

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The Role Of Vascular Endothelial Growth Factor At The Blood-Brain Barrier In Diabetes, Aileen J. Marcelo Jan 2012

The Role Of Vascular Endothelial Growth Factor At The Blood-Brain Barrier In Diabetes, Aileen J. Marcelo

Theses, Dissertations and Capstones

Diabetes is a risk factor for stroke and vascular dementia. Clinical studies using gadolinium-magnetic resonance imaging techniques have shown diabetic patients exhibit a permeability increase at the blood-brain barrier (BBB) (Starr et al, 2003). The BBB, a vascular interface at the level of brain microvascular vessels, functions to provide nutrients and oxygen from the peripheral circulation, mediates waste efflux from the brain, and protects the brain from toxins. These functions are due to the presence of tight junction proteins. Animal studies have shown increased BBB permeability is due to a decrease in these proteins (Hawkins et al, 2007). Based on …

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Disparate Degrees Of Hypervariable Loop Flexibility Control T Cell Receptor Cross-Reactivity, Specificity, And Binding Mechanism, Daniel R. Scott, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Steven A. Corcelli, Brian M. Baker Dec 2011

Disparate Degrees Of Hypervariable Loop Flexibility Control T Cell Receptor Cross-Reactivity, Specificity, And Binding Mechanism, Daniel R. Scott, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Steven A. Corcelli, Brian M. Baker

Food for Health: Publications

αβ T cell receptors recognize multiple antigenic peptides bound and presented by major histocompatibility complex molecules. TCR cross-reactivity has been attributed in part to flexibility of the complementarity-determining region loops, yet there have been limited direct studies of loop dynamics to determine the extent of its role. Here we studied the flexibility of the binding loops of the αβ TCR A6 utilizing crystallographic, spectroscopic, and computational methods. A significant role for flexibility in binding and cross-reactivity was indicated only for the CDR3α and CDR3β hypervariable loops. Examination of the energy landscapes of these two loops indicated that CDR3β possesses a …

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Identification And Engineering Of Human Variable Regions That Allow Expression Of Stable Single-Chain T Cell Receptors, David H. Aggen, Adam S. Chervin, Francis K. Insaidoo, Kurt H. Piepenbrink, Brian M. Baker, David M. Kranz Apr 2011

Identification And Engineering Of Human Variable Regions That Allow Expression Of Stable Single-Chain T Cell Receptors, David H. Aggen, Adam S. Chervin, Francis K. Insaidoo, Kurt H. Piepenbrink, Brian M. Baker, David M. Kranz

Food for Health: Publications

Single-chain antibody fragments (scFv), consisting of two linked variable regions (VH and VL), are a versatile format for engineering and as potential antigen-specific therapeutics. Although the analogous format for T cell receptors (TCRs), consisting of two linked V regions (Vα and Vβ; referred to here as scTv), could provide similar opportunities, all wild-type scTv proteins examined to date are unstable. This obstacle has prevented scTv fragments from being widely used for engineering or therapeutics. To further explore whether some stable human scTv fragments could be expressed, we used a yeast system in which display of properly folded …

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Fluorine Substitutions In An Antigenic Peptide Selectively Modulate T Cell Receptor Binding In A Minimally Perturbing Manner, Kurt H. Piepenbrink, Oleg Y. Borbulevych, Ruth F. Sommese, John Clemens, Kathrynq M. Armstrong, Clare Desmond, Priscilla Do, Brian M. Baker Jan 2011

Fluorine Substitutions In An Antigenic Peptide Selectively Modulate T Cell Receptor Binding In A Minimally Perturbing Manner, Kurt H. Piepenbrink, Oleg Y. Borbulevych, Ruth F. Sommese, John Clemens, Kathrynq M. Armstrong, Clare Desmond, Priscilla Do, Brian M. Baker

Food for Health: Publications

T cell receptor (TCR) recognition of antigenic peptides bound and presented by major histocompatibility complex (MHC) molecules forms the basis of the cellular immune response to pathogens and cancer. TCRs bind peptide/MHC molecules weakly and with fast kinetics, features which have hindered detailed biophysical studies of these interactions. Modified peptides resulting in enhanced TCR binding could help overcome these challenges. Further, there is considerable interest in using modified peptides with enhanced TCR binding as the basis for clinical vaccines. Here, we studied how fluorine substitutions in an antigenic peptide can selectively impact TCR recognition. Using a structure-guided design approach, we …

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Fluprostenol-Induced Mapk Signaling Is Independent Of Aging In Fischer 344/Nniahsd X Brown Norway/Binia Rat Aorta, Kevin M. Rice, Ernest M. Walker, Sunil K. Kakarla, Satyanarayana Paturi, Miaozong Wu, Sumit Narula, Eric R. Blough Jan 2010

Fluprostenol-Induced Mapk Signaling Is Independent Of Aging In Fischer 344/Nniahsd X Brown Norway/Binia Rat Aorta, Kevin M. Rice, Ernest M. Walker, Sunil K. Kakarla, Satyanarayana Paturi, Miaozong Wu, Sumit Narula, Eric R. Blough

MIIR Faculty Research

The factors that regulate vascular mechanotransduction and how this process may be altered with aging are poorly understood and have not been widely studied. Recent data suggest that increased tissue loading can result in the release of prostaglandin F2 alpha (PGF2α) and other reports indicate that aging diminishes the ability of the aged aorta to activate mitogen activated protein kinase (MAPK) signaling in response to increased loading. Using ex vivo incubations, here we investigate whether aging affects the ability of the aorta to induce phosphorylation of extracellular signal-regulated kinase 1/2 (ERK½-MAPK), p38-MAPK, and Jun N-terminal kinase (JNK-MAPK) activation following stimulation …

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