Read by QxMD icon Read

Infection and Immunity

Stefano Mancini, Carmen Menzi, Frank Oechslin, Philippe Moreillon, José Manuel Entenza
Streptococcus gordonii and related species of oral viridans group streptococci (VGS) are common etiological agents of infective endocarditis (IE). We explored vaccination as a strategy to prevent VGS- IE, using a novel antigen presenting system based on non-genetically modified Lactococcus lactis displaying vaccinogens on its surface.Hsa and PadA are surface-located S. gordonii proteins implicated in platelet adhesion and aggregation, which are key steps in the pathogenesis of IE. This function makes them ideal targets for vaccination against VGS- IE...
October 10, 2016: Infection and Immunity
J Liu, D T Bolick, G L Kolling, Z Fu, R L Guerrant
Malnutrition and cryptosporidiosis form a vicious cycle and lead to acute and long-term growth impairment in children from developing countries. Insights into mechanisms underlying the vicious cycle will help to design rational therapies to mitigate this infection. We test the effect of short term protein malnutrition on C. parvum infection in a murine model by examining stool shedding, tissue burden and histologic change, and explore the mechanism underlying the interaction between malnutrition and Cryptosporidiosis through immunostaining and immunoblotting...
October 10, 2016: Infection and Immunity
Cristina Faralla, Gabrielle A Rizzuto, David E Lowe, Byoungkwan Kim, Cara Cooke, Lawrence R Shiow, Anna I Bakardjiev
Intrauterine infection is a major detriment for maternal-child health and occurs despite local mechanisms that protect the maternal-fetal interface from a wide variety of pathogens. The bacterial pathogen Listeria monocytogenes causes spontaneous abortion, stillbirth, and preterm labor in humans, and serves as a model for placental pathogenesis. Given the unique immunological environment of the maternal-fetal interface we hypothesized that virulence determinants with placental tropism are required for infection of this tissue...
October 10, 2016: Infection and Immunity
Laura Schoenlaub, Rama Cherla, Yan Zhang, Guoquan Zhang
Our recent study demonstrated that virulent Coxiella burnetii Nine Mile phase I (NMI) is capable of infecting and replicating within peritoneal B1a cells and that B1a cells play an important role in host defense against C. burnetii infection in mice. However, it remains unknown if avirulent Nine Mile phase II (NMII) can infect and replicate in B1a cells and whether NMI and NMII can differentially interact with B1a cells. In this study, we examined if NMI and NMII can differentially modulate host cell apoptotic signaling in B1a cells...
October 10, 2016: Infection and Immunity
Dominic J Pollard, Joanna C Young, Valentina Covarelli, Silvia Herrera-León, Thomas R Connor, Maria Fookes, Danielle Walker, Aurora Echeita, Nicholas R Thomson, Cedric N Berger, Gad Frankel
Salmonella spp. utilize type III secretion systems (T3SS) to translocate effectors into the cytosol of mammalian host cells, subverting cell signaling and facilitating the onset of gastroenteritis. In this study we compared a draft genome assembly of S. enterica subsp. salamae strain 3588/07 (S. salamae) against the genomes of S. enterica subsp. enterica serovar Typhimurium strain LT2 and S. bongori strain 12419. S. salamae encode the Salmonella pathogenicity island (SPI)-1; SPI-2 and the locus of enterocyte effacement (LEE) T3SSs...
October 10, 2016: Infection and Immunity
Kazunobu Asano, Zhiliang Wu, Piyarat Srinontong, Takahide Ikeda, Isao Nagano, Hirokuyi Morita, Yoichi Maekawa
Infectious microorganisms often modify host immunity to escape from immune elimination. Trichinella is a unique nematode of the helminth family, which parasitize the inside of host muscle cells without robust eliminative reactions. There are two main species in genus Trichinella, encapsulated (T. spiralis(Ts), T. britovi) and non-encapsulated (T. pseudospiralis(Tp)). It has already been established that Trichinella infection affects host immune responses in several experimental immune diseases in animal models; however, most of those studies were done using Ts infection...
October 10, 2016: Infection and Immunity
Casey M Gries, Eric L Bruger, Derek E Moormeier, Tyler D Scherr, Christopher M Waters, Tammy Kielian
S. aureus is a leading cause of community- and nosocomial-acquired infections, with a propensity for biofilm formation. S. aureus biofilms actively skew the host immune response toward an anti-inflammatory state; however, the biofilm effector molecules and their mechanism(s) of action responsible for this phenomenon remain to be fully defined. The essential bacterial second messenger cyclic diadenylate monophosphate (c-di-AMP) is an emerging pathogen-associated molecular pattern during intracellular bacterial infections, where c-di-AMP secretion into the infected host cytosol induces a robust type I interferon (IFN) response...
October 10, 2016: Infection and Immunity
L F S Batista, Y T Utsunomiya, T B F da Silva, R A Dias, T Y Tomokane, A D Pacheco, V L R da Matta, F T Silveira, M Marcondes, C M Nunes, M D Laurenti
A genome-wide association study (GWAS) could unravel the complexity of the cell-mediated immunity (CMI) to canine leishmaniasis (CanL). Thereby we committed to scan 110,165 single-nucleotide polymorphisms (SNPs) aiming to identify chromosomal regions associated to leishmanin skin test (LST), lymphocyte proliferation assay (LPA) and cytokines responses to further understanding the role played by the CMI in the outcome of the natural Leishmania infantum infection in 189 dogs. Based on LST and LPA, four CMI profiles were identified (LST-/LPA-, LST+/LPA-, LST-/LPA+ and LST+/LPA+), which were not associated to subclinical infected or diseased dogs...
October 10, 2016: Infection and Immunity
Pardeep Kumar, F Matthew Kuhlmann, Kirandeep Bhullar, Hyungjun Yang, Bruce A Vallance, Lijun Xia, Qingwei Luo, James M Fleckenstein
At present, there is no vaccine for enterotoxigenic E. coli (ETEC), an important cause of diarrheal illness. Nevertheless, recent microbial pathogenesis studies have identified a number of molecules produced by ETEC that contribute to its virulence and which provide novel antigenic targets to complement canonical vaccine approaches. EtpA is a secreted two-partner adhesin, that is conserved within the ETEC pathovar. EtpA interacts with the tips of ETEC flagella to promote bacterial adhesion, toxin delivery and intestinal colonization by forming molecular bridges between the bacteria and the epithelial surface...
October 10, 2016: Infection and Immunity
Nathan K Archer, Nithin D Adappa, James N Palmer, Noam A Cohen, Jan M Harro, Steven K Lee, Lloyd S Miller, Mark E Shirtliff
Approximately 20% of the population is persistently colonized by S. aureus in the nares. Th17-like immune responses mediated by the IL-17 family of cytokines and neutrophils are becoming recognized as relevant host defense mechanisms for resolution of S. aureus mucocutaneous infections. Since antimicrobial peptides are regulated by the IL-17 cytokines, we sought to determine the role of IL-17 cytokines in production of antimicrobial peptides in a murine model of S. aureus nasal carriage. We discovered that nasal tissue supernatants have anti-staphylococcal activity, and mice deficient in both IL-17A and IL-17F lost the ability to clear S...
October 10, 2016: Infection and Immunity
Jiangwei Yao, Megan E Ericson, Matthew W Frank, Charles O Rock
Enoyl-acyl carrier protein reductase catalyzes the last step in each elongation cycle of type II bacterial fatty acid synthesis and is a key regulatory protein in bacterial fatty acid synthesis. The facultative intracellular pathogen Listeria monocytogenes encodes two functional enoyl-ACP isoforms based on their ability to complement the temperature-sensitive growth phenotype of E. coli strain JP1111 (fabI(Ts)). The FabI isoform was inactivated by the FabI selective inhibitor AFN-1252, but the FabK isoform was not affected by the drug as expected...
October 10, 2016: Infection and Immunity
Marie Wrande, Helene Andrews-Polymenis, Donna J Twedt, Olivia Steele-Mortimer, Steffen Porwollik, Michael McClelland, Leigh A Knodler
Intestinal epithelial cells provide an important colonization niche for Salmonella enterica serovar Typhimurium (S Typhimurium) during gastrointestinal infections. In infected epithelial cells, a sub-population of S. Typhimurium damage their internalization vacuole, leading to escape from the Salmonella-containing vacuole (SCV) and extensive proliferation in the cytosol. Little is known about the bacterial determinants of nascent SCV lysis and subsequent survival and replication of Salmonella in the cytosol...
October 3, 2016: Infection and Immunity
Sue-Jie Koo, Imran Chowdhury, Bartosz Szczesny, Xianxiu Wan, Nisha J Garg
BACKGROUND: Trypanosoma cruzi is the causative agent of chronic chagasic cardiomyopathy. Why macrophages (mϕs), the early responders to infection, fail to achieve parasite clearance is not known. METHODS: Mouse (RAW 264.7) and human (THP-1 and primary) mϕs were infected with T. cruzi TcI isolates, SylvioX10/4 (SYL, virulent) and TCC (non-pathogenic), for 3 h and 18 h that represent mϕ stimulation and infection states, respectively. Mϕs incubated with LPS/IFN-γ and IL-4 were used as controls...
October 3, 2016: Infection and Immunity
Hannah K Bayes, Neil D Ritchie, Thomas J Evans
Chronic pulmonary infection with Pseudomonas aeruginosa is a feature of cystic fibrosis (CF) and other chronic lung diseases. Cytokines of the IL-17 family have been proposed as important in the host response to P. aeruginosa infection through augmenting antibacterial immune responses, although their pro-inflammatory effect may contribute to lung damage that occurs as a result of chronic infection. We set out to explore the role of IL-17 in the host response to chronic P. aeruginosa infection. We used a murine model of chronic pulmonary infection with CF-related strains of P...
October 3, 2016: Infection and Immunity
Kristen E Rennoll-Bankert, M Sayeedur Rahman, Mark L Guillotte, Stephanie S Lehman, Magda Beier-Sexton, Joseph J Gillespie, Abdu F Azad
Rickettsiae are obligate intracellular pathogens that induce their uptake into non-phagocytic cells; however, the events instigating this process are incompletely understood. Importantly, diverse Rickettsia species are predicted to utilize divergent mechanisms to colonize host cells, as nearly all adhesins and effectors involved in host cell entry are differentially encoded in diverse Rickettsia species. One particular effector, RalF, a sec-7 domain containing protein that functions as a guanine nucleotide exchange factor of ADP-ribosylation factors (Arfs), is critical for R...
October 3, 2016: Infection and Immunity
Mike Khan, Jerome S Harms, Fernanda M Marim, Leah Armon, Cherisse L Hall, Yi-Ping Liu, Menachem Banai, Sergio C Oliveira, Gary A Splitter, Judith A Smith
Brucella species are facultative intracellular bacteria that cause brucellosis, a chronic debilitating disease significantly impacting global health and prosperity. Much remains to be learned about how Brucella spp. succeed in sabotaging immune host cells and how Brucella respond to environmental challenges. Multiple types of bacteria employ the prokaryotic second messenger cyclic-di-GMP (c-di-GMP) to coordinate responses to shifting environments. To determine the role of c-di-GMP in Brucella physiology and in shaping host-Brucella interactions, we utilized c-di-GMP regulatory enzyme deletion mutants...
September 26, 2016: Infection and Immunity
Martin Lappann, Andreas Otto, Madita Brauer, Dörte Becher, Ulrich Vogel, Kay Johswich
Neisseria meningitidis, the meningococcus, bears the potential of life-threatening invasive diseases, but it usually colonizes the nasopharynx without causing any symptoms. Within the nasopharynx, Neisseria meningitidis must face temperature changes depending on the ambient air temperature. Indeed, the nasopharyngeal temperature can be substantially lower than 37°C, the temperature commonly used in experimental settings. Here, we compared meningococcal biofilm formation, autoaggregation and cellular adherence between 32°C and 37°C and found a clear increase in all these phenotypes at 32°C, suggestive for a stronger in vivo colonization capability at this temperature...
September 26, 2016: Infection and Immunity
José L Reyes, Fernando Lopes, Gabriella Leung, Nicole L Mancini, Chelsea E Matisz, Arthur Wang, Emma A Thomson, Nicholas Graves, John Gilleard, Derek M McKay
Awareness of the immunological underpinnings of host-parasite interactions may reveal immune signaling pathways that could be used to treat inflammatory disease in humans. Previously we showed that infection with the rat tapeworm Hymenolepis diminuta, used as a model helminth, or systemic delivery of worm antigen (HdAg) significantly reduced the severity of dinitrobenzene sulphonic acid (DNBS)-induced colitis in mice. Extending these analyses, intraperitoneal injection of HdAg dose-dependently suppressed dextran sodium sulphate (DSS)-induced colitis and this was paralleled by reduced IFNγ, IL-17 and TNFα and increased IL-10 production from mitogen-activated splenocytes...
September 26, 2016: Infection and Immunity
Niharika Sharma-Chawla, Vicky Sender, Olivia Kershaw, Achim D Gruber, Julia Volckmar, Birgitta Henriques-Normark, Sabine Stegemann-Koniszewski, Dunja Bruder
Influenza A virus (IAV) and Streptococcus pneumoniae (S. pn.) are major causes of respiratory tract infections, particularly during co-infection. The synergism between these two pathogens is characterized by a complex network of dysregulated immune responses, some of which last until recovery post IAV infection. Despite the high serotype-diversity of S. pn. and the serotype-replacement observed since the introduction of conjugate vaccines, little is known about pneumococcal strain-dependency in the enhanced susceptibility to severe secondary S...
September 19, 2016: Infection and Immunity
Cortney L Armstrong, Irina Miralda, Adam C Neff, Shifu Tian, Aruna Vashishta, Lisandra Perez, Junyi Le, Richard J Lamont, Silvia M Uriarte
Filifactor alocis, is a recently recognized periodontal pathogen, however little is known regarding its interactions with the immune system. As the first responder phagocytic cells, neutrophils are recruited in large numbers to the periodontal pocket, where they play a crucial role in the innate defense of the periodontium. Thus, in order to colonize, successful periodontal pathogens must devise means to interfere with neutrophil chemotaxis and activation. In this study, we assessed major neutrophil functions including degranulation and cell migration associated with the p38 MAPK signaling pathway upon challenge with F...
September 19, 2016: 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"