journal
MENU ▼
Read by QxMD icon Read
search

Infection and Immunity

journal
https://www.readbyqxmd.com/read/28630074/the-enterohaemorrhagic-escherichia-coli-effector-espw-triggers-actin-remodeling-in-a-rac1-dependent-manner
#1
Pamela Sandu, Valerie F Crepin, Hauke Drechsler, Andrew D McAinsh, Gad Frankel, Cedric N Berger
Enterohaemorrhagic Escherichia coli (EHEC) is a diarrheagenic pathogen that colonizes the gut mucosa and induces attaching-and-effacing lesions. EHEC employs a type III secretion system (T3SS) to translocate 50 effector proteins that hijack and manipulate host cell signalling pathways, which allow bacterial colonization, subversion of immune responses and disease progression. The aim of this study was to characterize the T3SS effector EspW. We found espW in the sequenced O157:H7 and non-O157 EHEC strains as well as in Shigella boydii Furthermore, a truncated version of EspW, containing the first 206 residues is present in EPEC strains belonging to serotype O55:H7...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630073/new-insights-into-the-roles-of-lpf-and-stg-fimbriae-in-salmonella-interactions-with-enterocytes-and-m-cells
#2
Amanda M Gonzales, Shyra Wilde, Kenneth L Roland
Salmonella enterica serovar Typhi causes the systemic disease typhoid fever. After ingestion, it adheres to and invades the host epithelium while evading the host innate immune response, causing little if any inflammation. Conversely, S Typhimurium causes gastroenteritis in humans and thrives in the inflamed gut. Upon entering the host, S Typhimurium preferentially colonizes Peyer's patches, a lymphoid organ in which microfold cells (M cells) overlay an arrangement of B cells, T cells, and antigen presenting cells...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630072/pseudomonas-quinolone-signal-pqs-induces-oxidative-stress-and-inhibits-heme-oxygenase-1-expression-in-lung-epithelial-cells
#3
Maher Y Abdalla, Traci Hoke, Javier Seravalli, Barbara L Switzer, Melissa Bavitz, Jill D Fliege, Peter J Murphy, Bradley E Britigan
Pseudomonas aeruginosa (PA) causes lung infection in patients with cystic fibrosis (CF). Pseudomonas Quinolone Signal (PQS) is a secreted PA virulence factor that contributes to the pathogenicity of PA. We were able to detect PQS in sputum samples from CF patients infected with PA, but not in samples from uninfected patients. We then tested the hypothesis that PQS induces oxidative stress in host cells by determining the ability of PQS to induce production of reactive oxygen species (ROS) in lung epithelial cells (A549 and primary normal human bronchial epithelial (NHBE)) and macrophages (J774A...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630071/albumin-inhibits-pseudomonas-aeruginosa-quorum-sensing-and-alters-polymicrobial-interactions
#4
Allie Clinton Smith, Anne Rice, Bryan Sutton, Rebecca Gabrilska, Aimee K Wessel, Marvin Whiteley, Kendra P Rumbaugh
Polymicrobial interactions are complex and can influence the course of an infection, as is the case when two or more species exhibit a synergism that produces a disease state not seen with any of the individual species alone. Cell-to-cell signaling is key to many of these interactions, but little is understood about how the host environment influences polymicrobial interactions or signaling between bacteria. Chronic wounds are typically polymicrobial, with Staphylococcus aureus and Pseudomonas aeruginosa being the two most commonly isolated species...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630070/regulation-of-type-iii-secretion-of-translocon-and-effector-proteins-by-the-esab-esal-esam-complex-in-edwardsiella-tarda
#5
Lu Yi Liu, Pin Nie, Hong Bing Yu, Hai Xia Xie
The type III secretion system (T3SS) plays a crucial role in the pathogenesis of many Gram-negative bacteria, including Edwardsiella tarda, an important fish pathogen. Within the E. tarda T3SS, there are three proteins (EsaB/EsaL/EsaM) that are homologous to proteins present in many other bacteria, including SpiC/SsaL/SsaM in Salmonella, SepD/SepL/CesL in EPEC and EHEC, and YscB/YopN/SycN in Yersinia EsaL was found to interact with both EsaB and EsaM within the bacterial cell, as revealed by a co-immunoprecipitation assay...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630069/degradation-of-incretins-and-modulation-of-blood-glucose-levels-by-periodontopathic-bacterial-dipeptidyl-peptidase-4
#6
Yuko Ohara-Nemoto, Manami Nakasato, Yu Shimoyama, Tomomi T Baba, Takeshi Kobayakawa, Toshio Ono, Takashi Yaegashi, Shigenobu Kimura, Takayuki K Nemoto
Severe periodontitis is known to aggravate diabetes mellitus, though molecular events related to that link have not been fully elucidated. Porphyromonas gingivalis, a major pathogen of periodontitis, expresses dipeptidyl peptidase 4 (DPP4), which is involved in regulation of blood glucose levels by cleaving incretins in humans. We examined the enzymatic characteristics of DPP4 from P. gingivalis as well as two other periodontopathic bacteria, Tannerella forsythia and Prevotella intermedia, and determined whether it is capable of regulating blood glucose levels...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630068/ehrlichia-chaffeensis-trp120-moonlights-as-a-hect-e3-ligase-involved-in-self-and-host-ubiquitination-to-influence-protein-interactions-and-stability-for-intracellular-survival
#7
Bing Zhu, Seema Das, Shubhajit Mitra, Tierra R Farris, Jere W McBride
Ehrlichia chaffeensis secretes tandem repeat protein (TRP) effectors that are involved in a diverse array of host cell interactions, some of which directly activate cell signaling pathways, and reprogram host gene transcription to promote survival in the mononuclear phagocyte. However, the molecular details of these effector-host interactions and roles in pathobiology are incompletely understood. In this study, we determined that the E. chaffeensis effector, TRP120, is post-translationally modified by ubiquitin (Ub), and ubiquitination occurs through intrinsic and host-mediated HECT ligase activity...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630067/sipa-activation-of-caspase-3-is-a-decisive-mediator-of-host-cell-survival-at-early-stages-of-salmonella-typhimurium-infection
#8
Anne McIntosh, Lynsey M Meikle, Michael Ormsby, Beth A McCormick, John M Christie, James M Brewer, Mark Roberts, Daniel M Wall
Salmonella invasion protein A (SipA) is a dual function effector protein that plays roles in both actin polymerization and caspase-3 activation in intestinal epithelial cells. To date its function in other cell types has remained largely unknown despite its expression in multiple cell types and its extracellular secretion during infection. Here we show that in macrophages SipA induces increased caspase-3 activation early in infection. This activation required a threshold level of SipA linked to multiplicity of infection and may be a limiting factor controlling bacterial numbers in infected macrophages...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630066/porphyromonas-gulae-activates-unprimed-and-ifn%C3%AE-primed-macrophages-via-the-pattern-recognition-receptors-tlr-2-tlr-4-and-nod2
#9
James A Holden, Neil M O'Brien-Simpson, Jason C Lenzo, Rebecca K H Orth, Ashley Mansell, Eric C Reynolds
Porphyromonas gulae is an anaerobic, Gram-negative coccobacillus that has been associated with periodontal disease in companion animals. The aims of this study were to analyse the ligation of pattern recognition receptors by P. gulae and the subsequent activation of macrophages. Exposure of HEK cells transfected with Toll-like receptors or NOD-like receptors to P. gulae resulted in the ligation of TLR2, TLR4 and NOD2. The effect of this engagement of receptors was investigated by measuring the synthesis of nitric oxide, CD86 expression and inflammatory cytokine production using wild type, TLR2-/- and TLR4-/- macrophages...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630065/ccr5-is-involved-in-interruption-of-pregnancy-in-mice-infected-with-toxoplasma-gondii-during-early-pregnancy
#10
Maki Nishimura, Kousuke Umeda, Masayuki Suwa, Hidefumi Furuoka, Yoshifumi Nishikawa
Toxoplasmosis can cause abortion in pregnant humans and other animals; however, the mechanism of abortion remains unknown. C-C chemokine receptor type 5 (CCR5) is essential for host defense in T. gondii infection. To investigate the relationship between CCR5 and abortion in toxoplasmosis, we inoculated wild-type and CCR5-deficient (CCR5(-/-)) mice with T. gondii tachyzoites intraperitoneally on day 3 of pregnancy (E3). The pregnancy rate decreased as pregnancy progressed in the infected wild-type mice. Histopathologically, no inflammatory lesions were observed in the fetoplacental tissues...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630064/pneumolysin-dependent-calpain-activation-and-il-1%C3%AE-secretion-in-macrophages-infected-with-streptococcus-pneumoniae
#11
Rendong Fang, Rui Wu, Huihui Du, Meilan Jin, Yajing Liu, Guihua Lei, Bing Jiang, Zehui Lei, Yuanyi Peng, Kui Nie, Kohsuke Tsuchiya
Pneumolysin (PLY), a major virulence factor of Streptococcus pneumoniae, is a pore-forming cytolysin that modulates host innate responses contributing to host defense against and pathogenesis of pneumococcal infections. Interleukin-1α (IL-1α) has been shown to be involved in tissue damage in a pneumococcal pneumonia model, however, the mechanism by which this cytokine is produced during S. pneumoniae infection remains unclear. In this study, we examined the role of PLY in IL-1α production. Although the strains induced similar levels of pro-IL-1α expression, wild-type S...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630063/listeria-vectored-vaccine-expressing-the-mycobacterium-tuberculosis-30-kda-major-secretory-protein-via-the-constitutively-active-prfa-regulon-boosts-bcg-efficacy-against-tuberculosis
#12
Qingmei Jia, Barbara Jane Dillon, Saša Masleša-Galić, Marcus A Horwitz
A potent vaccine against tuberculosis, one of the world's deadliest diseases, is needed to enhance the immunity of people worldwide, most of whom have been vaccinated with the partially effective BCG vaccine. Here we investigate novel live attenuated recombinant Listeria monocytogenes (rLm) vaccines expressing the Mycobacterium tuberculosis (Mtb) 30 kDa major secretory protein (r30/Ag85B) (rLm30) as heterologous booster vaccines in animals primed with BCG. Using three attenuated Lm vectors, rLm ΔactA (LmI), rLm ΔactA ΔinlB (LmII), and rLm ΔactA ΔinlBprfA* (LmIII), we constructed five rLm30 vaccine candidates expressing the r30 linked in-frame to the Lm Listeriolycin O signal sequence and driven by the hly promoter (h30) or linked in-frame to the ActA N-terminus and driven by the actA promoter (a30)...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630062/the-transcription-factor-nfat1-participates-in-the-induction-of-cd4-t-cell-functional-exhaustion-during-plasmodium-yoelii-infection
#13
Rachel Y Ames, Li-Min Ting, Inessa Gendlina, Kami Kim, Fernando Macian
Repeated stimulation of T cells that occurs in the context of chronic infection results in progressively reduced responsiveness of T cells to pathogen-derived antigens. This phenotype, known as T cell exhaustion, occurs during chronic infections caused by a variety of pathogens, from persistent viruses to parasites. Unlike the memory cells that typically form after successful pathogen clearance following an acute infection, exhausted T cells secrete lower levels of effector cytokines, proliferate less in response to cognate antigen, and up-regulate cell-surface inhibitory molecules such as PD-1 and LAG-3...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28630061/increased-resistance-to-intradermal-francisella-tularensis-lvs-infection-by-inactivation-of-the-sts-phosphatases
#14
Kaustubh Parashar, Erik Kopping, David Frank, Vinaya Sampath, David G Thanassi, Nick Carpino
The Suppressor of TCR signaling proteins (Sts-1 and Sts-2) are two homologous phosphatases that negatively regulate signaling pathways in a number of hematopoietic lineages, including T lymphocytes. Mice lacking Sts expression are characterized by enhanced T cell responses. Additionally, a recent study demonstrated that Sts-/- mice are profoundly resistant to systemic infection of Candida albicans, with resistance characterized by enhanced survival, more rapid fungal clearance in key peripheral organs, and an altered inflammatory response...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28607101/positive-and-negative-control-pathways-by-blood-components-for-intermedilysin-production-in-streptococcus-intermedius
#15
Toshifumi Tomoyasu, Takahiro Yamasaki, Shinya Chiba, Shingo Kusaka, Atsushi Tabata, Robert A Whiley, Hideaki Nagamune
Streptococcus intermedius is an opportunistic bacterial pathogen secreting a human-specific cytolysin called intermedilysin (ILY) as a major pathogenic factor. This bacterium can degrade glycans into monosaccharides using two glycosidases, multisubstrate glycosidase A (MsgA) and neuraminidase (NanA). Here, we detected a strong hemolytic activity mediated by ILY when Sintermedius PC574 was cultured in fetal bovine serum (FBS) as compared to the standard culture medium. FBS-cultured cells also showed higher MsgA and NanA activity although overproduction of ILY in FBS was undetectable in mutants nanA-null and msgA-null...
June 12, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28607100/control-of-mucosal-candidiasis-in-the-zebrafish-swimbladder-depends-on-neutrophils-that-block-filament-invasion-and-drive-extracellular-trap-production
#16
Remi L Gratacap, Allison K Scherer, Brittany G Seman, Robert T Wheeler
Candida albicans is a ubiquitous mucosal commensal that is normally prevented from causing acute or chronic invasive disease. Neutrophils contribute to protection in oral infection but exacerbate vulvovaginal candidiasis. To dissect the role of neutrophils during mucosal candidiasis we took advantage of a new, transparent zebrafish swimbladder infection model. Intravital microscopic tracking of individual animals revealed that blocking neutrophil recruitment leads to rapid mortality in this model through faster disease progression...
June 12, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28607099/inhibition-of-the-host-cell-lysosome-spreading-by-trypanosoma-cruzi-metacyclic-stage-specific-surface-molecule-gp90-down-regulates-parasite-invasion
#17
João Paulo Ferreira Rodrigues, Guilherme Hideki Takahashi Sant'ana, Maria Aparecida Juliano, Nobuko Yoshida
Successful infection by Trypanosoma cruzi, the agent of Chagas disease, is critically dependent on the host cell invasion by metacyclic trypomastigote (MT) forms. Two main metacyclic stage-specfic surface molecules, gp82 and gp90, play determinant roles in target cell invasion in vitro and in oral T. cruzi infection in mice. The structure and properties of gp82, which is highly conserved among T. cruzi strains, are well known. Informations on gp90 are still rather sparse. Here we attempted to fill that gap...
June 12, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28584162/chlamydia-muridarum-with-mutations-in-chromosomal-genes-tc0237-and-or-tc0668-are-deficient-in-colonizing-mouse-gastrointestinal-tract
#18
Lili Shao, Tianyuan Zhang, Quanzhong Liu, Jie Wang, Guangming Zhong
Chlamydia colonizes gastrointestinal tracts of both animals and humans. However, the medical significance remains unknown. We have previously shown that wild type C. muridarum spreads to and establishes stable colonization in the gastrointestinal tract following intravaginal inoculation. In the current study, we found that C. muridarum with mutations in chromosomal genes tc0237 and/or tc0668 were defective in spreading to the mouse gastrointestinal tract, which correlated with their attenuated pathogenicity in the upper genital tract...
June 5, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28584161/parasitic-protozoa-and-interactions-with-the-host-intestinal-microbiota
#19
Stacey L Burgess, Carol A Gilchrist, Tucker C Lynn, William A Petri
Parasitic protozoan infections represent a major health burden in the developing world and contribute significantly to morbidity and mortality. These infections are often associated with considerable variability in clinical presentation. An emerging body of work suggests that the intestinal microbiota may help to explain some of these differences in disease expression. The objective of this minireview is to synthesize recent progress in this rapidly advancing field. Studies in humans, animal models and in vitro concerning the contribution of the intestinal microbiota to infectious disease will be discussed...
June 5, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28559407/neutrophil-elastase-and-il17-expressed-in-the-pig-colon-during-brachyspira-hyodysenteriae-infection-synergistically-with-the-pathogen-induce-increased-mucus-transport-speed-and-production-via-mapk3
#20
Macarena P Quintana-Hayashi, Nazanin Navabi, Maxime Mahu, Vignesh Venkatakrishnan, Harvey R Fernandez, Freddy Haesebrouck, Frank Pasmans, Sara K Lindén
Brachyspira hyodysenteriae colonizes the pig colon resulting in mucoid hemorragic diarrhea and mucus layer changes. These changes are characterized by a disorganized mucus structure and a massive mucus induction with de novo expression of MUC5AC and increased production of MUC2. To investigate the mechanisms behind this altered mucin environment, we quantified the mRNA levels of mucin pathway genes and factors from the immune system in the colon of infected and control pigs, revealing upregulation of neutrophil elastase, SPDEF, FOXA3, MAPK3/ERK1, IL-17A, IL-1β, IL-6 and IL-8 expression...
May 30, 2017: Infection and Immunity
journal
journal
20322
1
2
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"