Read by QxMD icon Read

Infection and Immunity

Chiung-Yu Hung, Hao Zhang, Natalia Castro-Lopez, Gary R Ostroff, Payam Khoshlenar, Ambily Abraham, Garry T Cole, Austin Negron, Thomas Forsthuber, Tao Peng, John N Galgiani, Neil M Ampel, Jieh-Juen Yu
Developing an effective and safe recombinant vaccine requires microbe-specific antigens combined with an adjuvant/delivery system to strengthen protective immunity. In this study, we designed and expressed a multivalent, recombinant Coccidioides polypeptide antigen (rCpa1) that consists of three previously identified antigens (i.e., Ag2/Pra, Cs-Ag and Pmp1) and 5 pathogen-derived peptides with high affinity for human MHC II molecules. The purified rCpa1 was encapsulated into four types of yeast cell-wall particles containing various compositions of β-glucan, mannan and chitin or mixed with an oligonucleotide (ODN) containing 2 methylated dinucleotide CpG motifs...
August 13, 2018: Infection and Immunity
Hashini M Batugedara, Donovan Argueta, Jessica C Jang, Dihong Lu, Marissa Macchietto, Jaspreet Kaur, Shaokui Ge, Adler R Dillman, Nicholas V DiPatrizio, Meera G Nair
Helminths have co-evolved with their hosts resulting in the development of specialized host immune mechanisms and parasite-specific regulatory products. Identification of new pathways that regulate helminth infection could provide a better understanding of host-helminth interaction and may identify new therapeutic targets for helminth infection. Here we identify the endocannabinoid system as a new mechanism that influences host immunity to helminths. Endocannabinoids are lipid-derived signaling molecules that control important physiologic processes such as feeding behavior and metabolism...
August 13, 2018: Infection and Immunity
Rebecca A Keogh, Rachel L Zapf, Richard E Wiemels, Marcus A Wittekind, Ronan K Carroll
The Staphylococcus aureus cyclophilin PpiB is an intracellular peptidyl prolyl cistrans isomerase (PPIase) that has previously been shown to contribute to secreted nuclease and hemolytic activity. In this study, we investigate the contribution of PpiB to S. aureus virulence. Using a murine abscess model of infection, we demonstrate that a ppiB mutant is attenuated for virulence. We go on to investigate the mechanism through which PpiB protein contributes to virulence, in particular the contribution of PpiB PPIase activity...
August 13, 2018: Infection and Immunity
Holly A Morrison, David Lowe, Jennifer R Robbins, Anna I Bakardjiev
Listeria monocytogenes is a foodborne pathogen that infects the placenta and can cause pregnancy complications. Listeriosis infections usually occur as sporadic infections, but large outbreaks are also reported. Virulence from clinical isolates is rarely analyzed due to the large number of animals required, but this knowledge could help guide the response to an outbreak. We implemented a DNA barcode system using signature tags that allowed us to efficiently assay variations in virulence across a large number of isolates...
August 13, 2018: Infection and Immunity
Rajesh Mani, Manish Gupta, Anshu Malik, Ravi Tandon, Rajendra Prasad, Rakesh Bhatnagar, Nirupama Banerjee
Novel adjuvants are in demand for improving the efficacy of human vaccines. The immunomodulatory properties of Mycobacterium tuberculosis (Mtb) cell wall components have been highlighted in the formulation of complete Freund's adjuvant (CFA). We have explored the adjuvant potential of poly-α-L-glutamine (PLG), a lesser-known constituent of pathogenic mycobacterial cell wall. Immune parameters indicated that the adjuvant potency of PLG was statistically comparable to CFA and better than alum in the context of H1 antigen (Ag85B and ESAT-6 fusion)...
August 13, 2018: Infection and Immunity
Kristen M Reeder, Joseph J Mackel, Matthew S Godwin, Chad W Dunaway, Jonathan P Blackburn, Rakesh P Patel, Chad Steele
Humans are constantly exposed to the opportunistic mold Aspergillus fumigatus and disease caused by this pathogen is often determined by the magnitude of local and systemic immune responses. We have previously shown a protective role for IL-22 after acute A. fumigatus exposure. Here, employing IL22Cre R26ReYFP reporter mice, we identified iNKT cells, γδ T cells and ILC3 cells as lung cell sources of IL-22 in response to acute A. fumigatus exposure. As these cells often utilize common γ-chain cytokines for their development or maintenance, we determined the role of IL-7, IL-21 and IL-15 on lung IL-22 induction and A...
August 13, 2018: Infection and Immunity
Eric Mi, Jihong Li, Bruce A McClane
Clostridium perfringens type F strains, which produce C. perfringens enterotoxin (CPE), are a major cause of gastrointestinal infections, including the second most prevalent bacterial foodborne illness and 5-10% cases of antibiotic-associated diarrhea. Virulence of type F strains is primarily ascribable to CPE, which is synthesized only during sporulation. Many type F strains also produce NanI sialidase and carry a nan operon that facilitates uptake and metabolism of sialic acid liberated from glycoconjugates by NanI...
August 6, 2018: Infection and Immunity
Gabriela González-Espinoza, Elías Barquero-Calvo, Esteban Lizano-González, Alejandro Alfaro-Alarcón, Berny Arias-Gómez, Esteban Chaves-Olarte, Bruno Lomonte, Edgardo Moreno, Carlos Chacón-Díaz
Brucellosis is a bacterial disease of animals and humans. Brucella abortus barely activates the innate immune system at the onset of infection and this bacterium is resistant to the microbicidal action of complement (C'). Since C' stands as the first line of defense during bacterial invasions, we explored the role of C' in B. abortus infections. Brucella abortus infected mice depleted of C' with cobra venom factor (CVF) showed the same survival rate as the control group. The C'-depleted mice readily eliminated B...
August 6, 2018: Infection and Immunity
Irina Debnath, Anne M Stringer, Sara N Smith, Emily Bae, Harry L T Mobley, Joseph T Wade, Melanie M Pearson
Proteus mirabilis is a leading cause of catheter-associated urinary tract infections (CAUTIs) and urolithiasis. The transcriptional regulator MrpJ inversely modulates two critical aspects of P. mirabilis UTI progression: fimbria-mediated attachment, and flagella-mediated motility. Transcriptome data indicated a network of virulence-associated genes under MrpJ's control. Here we identify the direct gene regulon of MrpJ and its contribution to P. mirabilis pathogenesis, leading to the discovery of novel virulence targets...
August 6, 2018: Infection and Immunity
María Luisa Gil-Marqués, María Eugenía Pachón-Ibáñez, Jerónimo Pachón, Younes Smani
Hypoxia modulates bacterial virulence and inflammation response through the hypoxia-inducible factor-1α (HIF-1α). Here, we study the influence of hypoxia on Acinetobacter baumannii and Pseudomonas aeruginosa infections. In vitro hypoxia increases bactericidal activity of epithelial cells against A. baumannii reducing extracellular bacterial concentration (50.5 ± 7.5%) and against P. aeruginosa (90.8 ± 13.9%) 2h post-infection. The same happens in macrophages cells (67.6 ± 18.2% at 2h, and 50.3 ± 10.9% at 24 h, respectively)...
August 6, 2018: Infection and Immunity
Kimberly Perez, Robin Patel
Staphylococcus epidermidis is a leading cause of infections associated with indwelling medical devices, including prosthetic joint infection. While biofilm formation is assumed to be the main mechanism underlying the chronic infections S. epidermidis causes, we hypothesized that S. epidermidis also evades immune killing, contributing to its pathogenesis. Here, we show that prosthetic joint-associated S. epidermidis isolates can persist intracellularly within human fibroblasts and inside human and mouse osteoblasts...
July 30, 2018: Infection and Immunity
Christopher Phelps, Stephen Vadia, Eusondia Arnett, Yubo Tan, Xiaoli Zhang, Sarika Pathak-Sharma, Mikhail Gavrilin, Stephanie Seveau
Listeria monocytogenes is a facultative intracellular pathogen that infects a wide variety of cells causing the life-threatening disease listeriosis. L. monocytogenes virulence factors include two surface invasins, InlA and InlB, known to promote bacterial uptake by host cells, and the secreted pore-forming toxin listeriolysin O (LLO), which disrupts the phagosome to allow bacterial proliferation in the cytosol. In addition, plasma membrane perforation by LLO was shown to facilitate L. monocytogenes internalization into epithelial cells...
July 30, 2018: Infection and Immunity
Tatiana M Clemente, Minal Mulye, Anna V Justis, Srinivas Nallandhighal, Tuan M Tran, Stacey D Gilk
Coxiella burnetii is an obligate intracellular bacterium and the etiological agent of Q fever. Successful host cell infection requires the Coxiella Type IVB Secretion System (T4BSS), which translocates bacterial effector proteins across the vacuole membrane into the host cytoplasm, where they manipulate a variety of cell processes. To identify host cell targets of Coxiella T4BSS effector proteins, we determined the transcriptome of murine alveolar macrophages infected with a Coxiella T4BSS effector mutant. We identified a set of inflammatory genes that are significantly upregulated in T4BSS mutant-infected cells compared to mock-infected cells or cells infected with wild type (WT) bacteria, suggesting Coxiella T4BSS effector proteins downregulate expression of these genes...
July 30, 2018: Infection and Immunity
Jessica L Kelliher, Jana N Radin, Thomas E Kehl-Fie
Microbial pathogens must obtain all essential nutrients, including phosphate, from the host. To optimize phosphate acquisition in diverse and dynamic environments such as mammalian tissues, many bacteria use the PhoPR two-component system. Despite the necessity of this system for virulence in several species, PhoPR has not been studied in the major human pathogen Staphylococcus aureus To illuminate its role in staphylococcal physiology, we initially assessed whether PhoPR controls expression of the three inorganic phosphate (Pi ) importers (PstSCAB, NptA, and PitA) in S...
July 30, 2018: Infection and Immunity
Deena R Altman, Mitchell J Sullivan, Kieran I Chacko, Divya Balasubramanian, Theodore R Pak, William E Sause, Krishan Kumar, Robert Sebra, Gintaras Deikus, Oliver Attie, Hannah Rose, Martha Lewis, Yi Fulmer, Ali Bashir, Andrew Kasarskis, Eric E Schadt, Anthony R Richardson, Victor J Torres, Bo Shopsin, Harm van Bakel
Therapy for bacteremia caused by Staphylococcus aureus is often ineffective, even when treatment conditions are optimal according to experimental protocols. Adapted subclones, such as those bearing mutations that attenuate agr -mediated virulence activation, are associated with persistent infection and patient mortality. To identify additional alterations in agr -defective mutants, we sequenced and assembled the complete genomes of clone pairs from colonizing and infected sites of several patients in whom S...
July 30, 2018: Infection and Immunity
Brittany G Seman, Jessica L Moore, Allison K Scherer, Bailey A Blair, Sony Manandhar, Joshua M Jones, Robert T Wheeler
Candida albicans dimorphism is a crucial virulence factor during invasive candidiasis infections, which claim the lives of nearly one-half of those afflicted. It has long been believed that filaments drive tissue invasion and yeast mediate bloodstream dissemination, but observation of these activities during infection has been prevented by technical limitations. We used a transparent zebrafish infection model to more comprehensively analyze how C. albicans utilizes shape to disseminate and invade. This model facilitated the use of diverse, complementary strategies to manipulate shape, allowing us to monitor dissemination, invasion, and pathogenesis via intravital imaging of individual fungal cells throughout the host...
July 23, 2018: Infection and Immunity
Vesla Kullaya, Marien I de Jonge, Jeroen D Langereis, Christa E van der Gaast-de Jongh, Christian Büll, Gosse J Adema, Dirk Lefeber, Amelieke J Cremers, Blandina T Mmbaga, Phillip G de Groot, Quirijn de Mast, Andre J van der Ven
Platelets are increasingly recognized to play a role in the complications of Streptococcus pneumoniae infections. S. pneumoniae expresses neuraminidases, which may alter glycans on the platelet surface. In the present study, we investigated the capability of pneumococcal neuraminidase A (NanA) to remove sialic acid (desialylation) from the platelet surface, the consequences for the platelet activation status and reactivity, and the ability of neuraminidase inhibitors to prevent these effects. Our results show that soluble NanA induces platelet desialylation...
July 23, 2018: Infection and Immunity
Hiba Ibrahim, Basim Askar, Scott Hulme, Peter Neilson, Paul Barrow, Neil Foster
We studied the effect of two S Typhimurium (host adapted) strains (14028 and 4/74) and three S Choleraesuis (non-host adapted) strains (A50, A45 and B195) in human monocytes between 2-24h post-infection (pi); to investigate whether difference in the immune response may explain the much higher prevalence of sepsis in individuals infected with S Choleraesuis.Both serovars significantly increased production of cytokines associated with acute sepsis (TNF-α, IL-β and IL-6) but temporal differences occurred between these serovars and between different S Choleraesuis strains...
July 23, 2018: Infection and Immunity
Junhua Wang, Rita Cardoso, Nelson Marreros, Norbert Müller, Britta Lundström-Stadelmann, Myriam Siffert, Dominique A Vuitton, Franck Boué, Renyong Lin, Hao Wen, Bruno Gottstein
Alveolar echinococcosis (AE) is a lethal disease caused by infection with the metacestode stage of the helminth Echinococcus multilocularis , which develops into a tumor-like mass in susceptible intermediate hosts. The growth potential of this parasite stage is directly linked to the nature of the surrounding periparasitic immune-mediated processes. In a first step (experiment 1), mice were orally infected with E. multilocularis eggs, to be used for assessing the hepatic expression profiles of 15 selected cytokine and chemokine genes related to acquired immunity from 21 to 120 days post infection...
July 23, 2018: Infection and Immunity
Michael H Norris, Nawarat Somprasong, Herbert P Schweizer, Apichai Tuanyok
Burkholderia pseudomallei causes the severe disease melioidosis. The bacterium subverts the host immune system, replicates inside cells, and host mortality primarily results from sepsis related complications. Lipopolysaccharide (LPS) is a major virulence factor and mediator of sepsis that many pathogens capable of intracellular growth modify to reduce their immunological "foot print". The binding strength of B. pseudomallei LPS for human LPS binding protein (hLBP) was measured using surface plasmon resonance...
July 23, 2018: Infection and Immunity
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"