Search results for "Immune system"

Variation in the risk of being wounded: an overlooked factor in studies of invertebrate immune function?

2003

In invertebrates, wounding can trigger an immune response, and will often expose organisms to parasites and pathogens. Here we show that in the amphipod Gammarus pulex, wounding abundance is negatively correlated with PhenolOxidase activity (a major component of the invertebrate immune response), and that the occurrence and abundance of wounding is extremely high and varies significantly between five natural populations. In some populations the prevalence and abundance of wounds also varied between sexes. Given that, using and maintaining an efficient immune system is costly, we suggest that the frequency of wounding may be an important selective pressure influencing an organism's optimal i…

Kinetics of cytomegalovirus (CMV) pp65 and IE-1-specific IFNgamma CD8+ and CD4+ T cells during episodes of viral DNAemia in allogeneic stem cell tran…

2010

The dynamics of CMV pp65 and IE-1-specific IFNgamma-producing CD8(+) (IFNgamma CD8(+)) and CD4(+) (IFNgamma CD4(+)) T cells and CMV DNAemia were assessed in 19 pre-emptively treated episodes of active CMV infection. Peripheral counts of IFNgamma CD8(+) and IFNgamma CD4(+) T cells inversely correlated with CMV DNAemia levels (P = <0.001 and P = 0.003, respectively). A threshold value of 1.3 cells/microl predicting CMV DNAemia clearance was established for IFNgamma CD8(+) T cells (PPV, 100%; NPV, 93%) and for IFNgamma CD4(+) T cells (PPV, 100%; NPV, 75%). Undetectable T-cell responses were usually observed at the time of initiation of pre-emptive therapy. Either a rapid (within 7 days) or a d…

Immunological Characterization of Somatic and Excretory–Secretory Antigens of Echinostoma caproni (Trematoda: Echinostomatidae) in Experimentally Inf…

2004

The antigenic properties of somatic (SoP) and excretory-secretory products (ESP) of Echinostoma caproni were studied in experimentally infected rats. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis demonstrated a total of 15 and 9 major polypeptides, in the molecular weight range 10-165 kDa, in SoP and ESP products, respectively. Further analysis revealed some common as well as several unique polypeptides for each type of extract. A total of 2 polypeptides, weighing 58 and 115 kDa, were found in both types of antigen. Indirect enzyme-linked immunosorbent assay analysis using both types of antigens showed that rats developed a weak and slow response in infections with E. caproni. …

1982

Phase distribution chromatography (PDC) is demonstrated to be a powerful method for the correct determination of narrow molecular weight distributions. This is shown by comparing the molecular weight distributions (MWD) of polystyrenes obtained from PDC measurements with those obtained by Baker-Williams fractionation and by gel permeation chromatography. Four problems are formulated and analyzed which are closely connected with the calculation of the MWD from a measured PDC-elution curve at temperatures below the theta point of the system. Thus, the theory of PDC outlined previously is tested.

Cytomegalovirus Interleukin-10 Expression in Infected Cells Does Not Impair MHC Class I Restricted Peptide Presentation on Bystanding Antigen-Present…

2006

Human cytomegalovirus (HCMV) has evolved strategies to counteract its surveillance by the immune system. Mitigation of antiviral immune responses is considered critical for establishment of viral latency and for spread. Recently, a gene encoding an interleukin-10 homologue (cmvIL-10) has been discovered in the HCMV genome. Using recombinant cmvIL-10, several mostly immunosuppressive functions of the molecule have been described. However, the role of cmvIL-10 in the context of viral infection was not addressed. To be able to analyze this issue, we generated cmvIL- 10-negative viral mutants. Using these mutants, we tested whether the expression of cmvIL-10 by infected cells would render bysta…

Adaptation to host inVibrio vulnificus, a zoonotic pathogen that causes septicemia in fish and humans

2019

Vibrio vulnificus is a siderophilic pathogen spreading due to global warming. The zoonotic strains constitute a clonal-complex related to fish farms that are distributed worldwide. In this study, we applied a transcriptomic and single gene approach and discover that the zoonotic strains bypassed the iron requirement of the species thanks to the acquisition of two iron-regulated outer membrane proteins (IROMPs) involved in resistance to fish innate immunity. Both proteins have been acquired by horizontal gene transfer and are contributing to the successful spreading of this clonal-complex. We have also discovered that the zoonotic strains express a virulent phenotype in the blood of its main…

Origin of the interferon-inducible (2′-5′)oligoadenylate synthetases: cloning of the (2′-5′)oligoadenylate synthetase from the marine spongeGeodia cy…

1999

In vertebrates cytokines mediate innate (natural) immunity and protect them against viral infections. The cytokine interferon causes the induction of the (2′-5′)oligoadenylate synthetase [(2-5)A synthetase], whose product, (2′-5′)oligoadenylate, activates the endoribonuclease L which in turn degrades (viral) RNA. Three isoforms of (2-5)A synthetases exist, form I (40–46 kDa), form II (69 kDa), and form III (100 kDa). Until now (2-5)A synthetases have only been cloned from birds and mammals. Here we describe the cloning of the first putative invertebrate (2-5)A synthetase from the marine sponge Geodia cydonium. The deduced amino acid sequence shows signatures characteristic for (2-5)A synthe…

2013

The MHC-class I (MHC-I)-like viral (MHC-Iv) m152 gene product of murine cytomegalovirus (mCMV) was the first immune evasion molecule described for a member of the β-subfamily of herpesviruses as a paradigm for analogous functions of human cytomegalovirus proteins. Notably, by interacting with classical MHC-I molecules and with MHC-I-like RAE1 family ligands of the activatory natural killer (NK) cell receptor NKG2D, it inhibits presentation of antigenic peptides to CD8 T cells and the NKG2D-dependent activation of NK cells, respectively, thus simultaneously interfering with adaptive and innate immune recognition of infected cells. Although the m152 gene product exists in differentially glyco…

How Fragile We Are: Influence of Stimulator of Interferon Genes (STING) Variants on Pathogen Recognition and Immune Response Efficiency.

2022

AbstractThe STimulator of INterferon Genes (STING) protein is a cornerstone of the human immune response. Its activation by cGAMP upon the presence of cytosolic DNA stimulates the production of type I interferons and inflammatory cytokines which are crucial for protecting cells from infections. STING signaling pathway can also influence both tumor-suppressive and tumor-promoting mechanisms, rendering it an appealing target for drug design. In the human population, several STING variants exist and exhibit dramatic differences in their activity, impacting the efficiency of the host defense against infections. Understanding the differential molecular mechanisms exhibited by these variants is o…

Screening and Construction of Probiotic Strains with Enhanced Protective Properties against Intestinal Disorders

2011

Within the scope of the DEPROHEALTH project, a range of wild-type strains of Lactobacillus were analysed for their ability to interact with the host immune system. While the studied isolates interacted in a strain-specific way with immune cells, they seemed to have little and non-discriminative effect on epithelial cells. However, they were shown to facilitate the cross-talk between intestinal and immune cells. Studies conducted in mouse colitis models confirmed that specific strains possess higher intrinsic anti-inflammatory properties. Two of these were further engineered to produce murine IL10 and are presently being evaluated for their protective effect in a TNBS colitis model. Cell wal…