86 research outputs found
Oxidative Stress Resulting From Helicobacter pylori Infection Contributes to Gastric Carcinogenesis.
Helicobacter pylori is a gram-negative, microaerophilic bacterium that infects the stomach and can lead to, among other disorders, the development of gastric cancer. The inability of the host to clear the infection results in a chronic inflammatory state with continued oxidative stress within the tissue. Reactive oxygen species and reactive nitrogen species produced by the immune and epithelial cells damage the host cells and can result in DNA damage. H pylori has evolved to evoke this damaging response while blunting the host's efforts to kill the bacteria. This long-lasting state with inflammation and oxidative stress can result in gastric carcinogenesis. Continued efforts to better understand the bacterium and the host response will serve to prevent or provide improved early diagnosis and treatment of gastric cancer
Modulation of Human Immune Responses by Bovine Interleukin-10
Cytokines can be functionally active across species barriers. Bovine IL-10 has an amino acid sequence identity with human IL-10 of 76.8%. Therefore, the aim of this study was to evaluate whether bovine IL-10 has immunomodulatory activities on human monocytes and dendritic cells. Peripheral blood monocytes were isolated from healthy donors, and used directly or allowed to differentiate to dendritic cells under the influence of IL-4 and GM-CSF. Recombinant bovine IL-10 inhibited TLR induced activation of monocytes, and dose-dependently inhibited LPS-induced activation of monocyte-derived DCs comparable to human IL-10. By using blocking antibodies to either bovine IL-10 or the human IL-10 receptor it was demonstrated that inhibition of monocyte activation by bovine IL-10 was dependent on binding of bovine IL-10 to the human IL-10R. These data demonstrate that bovine IL-10 potently inhibits the activation of human myeloid cells in response to TLR activation. Bovine IL-10 present in dairy products may thus potentially contribute to the prevention of necrotizing enterocolitis and allergy, enhance mucosal tolerance induction and decrease intestinal inflammation and may therefore be applicable in infant foods and in immunomodulatory diets
Associations of faecal microbiota with influenza-like illness in participants aged 60 years or older:an observational study
Background People aged 60 years or older are at high risk for respiratory infections, one of the leading causes of mortality worldwide. Vaccination is the main way to protect against these infections; however, vaccination is less effective in older adults than in younger adults due to ageing of the immune system, so innovative strategies that improve vaccine responses could provide a major public health benefit. The gut microbiota regulates host immune homoeostasis and response against pathogens, but human studies showing the effects of the gut microbiota on respiratory infections in older adults are sparse. We aimed to investigate the composition of the microbiota in relation to respiratory infections and local and systemic immune markers in older adults during an influenza season. Methods In this observational study, participants were selected from an influenza-like illness (ILI) prospective surveillance cohort in which community-dwelling adults aged 60 years and older in the Netherlands were recruited through their general practitioner or the Civil Registry. Inclusion criteria have been described elsewhere. Participants completed questionnaires and self-reported symptoms. To measure microbiota composition, faecal samples were collected from participants registering an ILI event, with a follow-up (recovery) sample collected 7-9 weeks after the ILI event, and from asymptomatic participants not reporting any event throughout the season. We tested associations between microbiota profiles and a set of health-related variables, patient characteristics, and local and systemic immune markers. We cultured identified bacterial biomarkers for ILI with CaCo-2 cells in an in vitro intestinal epithelial model and measured the induced immune response. This study is registered with http://www.trialregister.nl, NL4666. Findings Between Oct 1, 2014, and April 30, 2015, 2425 older adults were recruited into the ILI surveillance cohort. From Oct 1, 2014, to June 15, 2015, faecal samples were collected from 397 participants, of whom 213 (54%) reported an ILI event once throughout the season and 184 (46%) did not. 192 ILI participants recovered and provided follow-up samples. Microbiota composition was altered during an ILI event. The Bacteroidetes (mean relative abundance 17.51% [SD 11.41] in the ILI group and 14.19% [10.02] in the control group; adjusted p=0.014) and the Proteobacteria (3.40% [8.10] in the ILI group and 1.57% [3.69] in the control group; adjusted p=0.015) were more abundant in the ILI group than in the control group. The abundance of Ruminococcus torques was positively associated with ILI and the abundance of Escherichia/Shigella, negatively correlated with alpha diversity, and negatively co-occurred with beneficial taxa, including butyrate producers. R torques was associated with pro-inflammatory profiles, both locally in faeces and systemically in blood. ILI-associated taxa (R torques and Escherichia coli) had symbiotic effects on the cellular immune response when cultured together in an in vitro model. Interpretation The abundances of specific bacteria could be used as potential biomarkers for susceptibility to respiratory infections and as targets for intervention in the ageing population. Copyright (C) 2020 The Author(s). Published by Elsevier Ltd
Decreased antibody response after severe acute respiratory syndrome coronavirus 2 vaccination in patients with Down syndrom
The risk of a severe course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in adults with Down syndrome is increased, resulting in an up to 10-fold increase in mortality, in particular in those >40 years of age. After primary SARS-CoV-2 vaccination, the higher risks remain. In this prospective observational cohort study, SARS-CoV-2 spike S1-specific antibody responses after routine SARS-CoV-2 vaccination (BNT162b2, messenger RNA [mRNA]-1273, or ChAdOx1) in adults with Down syndrome and healthy controls were compared. Adults with Down syndrome showed lower antibody concentrations after 2 mRNA vaccinations or after 2 ChAdOx1 vaccinations. After 2 mRNA vaccinations, lower antibody concentrations were seen with increasing age. In this prospective cohort study that included 222 adults with Down syndrome, a significantly lower antibody response was found after SARS-CoV-2 mRNA or vector vaccination compared to healthy controls. After mRNA vaccination, lower antibodies were found with increasing age
Decreased Antibody Response After Severe Acute Respiratory Syndrome Coronavirus 2 Vaccination in Patients With Down Syndrome
UNLABELLED: The risk of a severe course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in adults with Down syndrome is increased, resulting in an up to 10-fold increase in mortality, in particular in those >40 years of age. After primary SARS-CoV-2 vaccination, the higher risks remain. In this prospective observational cohort study, SARS-CoV-2 spike S1-specific antibody responses after routine SARS-CoV-2 vaccination (BNT162b2, messenger RNA [mRNA]-1273, or ChAdOx1) in adults with Down syndrome and healthy controls were compared. Adults with Down syndrome showed lower antibody concentrations after 2 mRNA vaccinations or after 2 ChAdOx1 vaccinations. After 2 mRNA vaccinations, lower antibody concentrations were seen with increasing age. CLINICAL TRIALS REGISTRATION: NCT05145348
mRNA-1273 COVID-19 vaccination in patients receiving chemotherapy, immunotherapy, or chemoimmunotherapy for solid tumours:a prospective, multicentre, non-inferiority trial
BACKGROUND: Patients with cancer have an increased risk of complications from SARS-CoV-2 infection. Vaccination to prevent COVID-19 is recommended, but data on the immunogenicity and safety of COVID-19 vaccines for patients with solid tumours receiving systemic cancer treatment are scarce. Therefore, we aimed to assess the impact of immunotherapy, chemotherapy, and chemoimmunotherapy on the immunogenicity and safety of the mRNA-1273 (Moderna Biotech, Madrid, Spain) COVID-19 vaccine as part of the Vaccination Against COVID in Cancer (VOICE) trial. METHODS: This prospective, multicentre, non-inferiority trial was done across three centres in the Netherlands. Individuals aged 18 years or older with a life expectancy of more than 12 months were enrolled into four cohorts: individuals without cancer (cohort A [control cohort]), and patients with solid tumours, regardless of stage and histology, treated with immunotherapy (cohort B), chemotherapy (cohort C), or chemoimmunotherapy (cohort D). Participants received two mRNA-1273 vaccinations of 100 μg in 0·5 mL intramuscularly, 28 days apart. The primary endpoint, analysed per protocol (excluding patients with a positive baseline sample [>10 binding antibody units (BAU)/mL], indicating previous SARS-CoV-2 infection), was defined as the SARS-CoV-2 spike S1-specific IgG serum antibody response (ie, SARS-CoV-2-binding antibody concentration of >10 BAU/mL) 28 days after the second vaccination. For the primary endpoint analysis, a non-inferiority design with a margin of 10% was used. We also assessed adverse events in all patients who received at least one vaccination, and recorded solicited adverse events in participants who received at least one vaccination but excluding those who already had seroconversion (>10 BAU/mL) at baseline. This study is ongoing and is registered with ClinicalTrials.gov, NCT04715438. FINDINGS: Between Feb 17 and March 12, 2021, 791 participants were enrolled and followed up for a median of 122 days (IQR 118 to 128). A SARS-CoV-2-binding antibody response was found in 240 (100%; 95% CI 98 to 100) of 240 evaluable participants in cohort A, 130 (99%; 96 to >99) of 131 evaluable patients in cohort B, 223 (97%; 94 to 99) of 229 evaluable patients in cohort C, and 143 (100%; 97 to 100) of 143 evaluable patients in cohort D. The SARS-CoV-2-binding antibody response in each patient cohort was non-inferior compared with cohort A. No new safety signals were observed. Grade 3 or worse serious adverse events occurred in no participants in cohort A, three (2%) of 137 patients in cohort B, six (2%) of 244 patients in cohort C, and one (1%) of 163 patients in cohort D, with four events (two of fever, and one each of diarrhoea and febrile neutropenia) potentially related to the vaccination. There were no vaccine-related deaths. INTERPRETATION: Most patients with cancer develop, while receiving chemotherapy, immunotherapy, or both for a solid tumour, an adequate antibody response to vaccination with the mRNA-1273 COVID-19 vaccine. The vaccine is also safe in these patients. The minority of patients with an inadequate response after two vaccinations might benefit from a third vaccination. FUNDING: ZonMw, The Netherlands Organisation for Health Research and Development
Regulation of Rac1 and Reactive Oxygen Species Production in Response to Infection of Gastrointestinal Epithelia.
Apurinic/Apyrimidinic Endonuclease 1 Restricts the Internalization of Bacteria Into Human Intestinal Epithelial Cells Through the Inhibition of Rac1.
The development of a bead-based multiplex immunoassay for the detection of IgG antibodies to CMV and EBV.
Latent infection with Cytomegalovirus (CMV) or Epstein-Bar virus (EBV) is associated with compromised immune responses. The commercially available ELISA-kits provide a semi-quantitative or qualitative detection of IgG antibodies against either CMV or EBV. To reduce the amount of sample needed and improve throughput and range of quantitation compared to ELISAs, a multiplex immunoassay (MIA) for the simultaneous quantitative detection of antibodies against CMV and two antigens of EBV (EBV capsid antigen (EBV-VCA) and EBV nuclear antigen 1 (EBNA-1)) was developed and standardized. Our assay shows a good correlation with the separate ELISAs, has a high specificity and is much more sensitive than the ELISAs. The MIA allows faster analysis of samples and can be combined with the MIA for detection of antibodies to measles, mumps, rubella and varicella zoster (MMRV) as published previously. In conclusion, the CMV-EBV MIA is a reliable assay that allows for more efficient detection of specific antibodies to CMV and EBV. This MIA therefore is especially useful for large-scale surveillance studies
The development of a bead-based multiplex immunoassay for the detection of IgG antibodies to CMV and EBV.
Latent infection with Cytomegalovirus (CMV) or Epstein-Bar virus (EBV) is associated with compromised immune responses. The commercially available ELISA-kits provide a semi-quantitative or qualitative detection of IgG antibodies against either CMV or EBV. To reduce the amount of sample needed and improve throughput and range of quantitation compared to ELISAs, a multiplex immunoassay (MIA) for the simultaneous quantitative detection of antibodies against CMV and two antigens of EBV (EBV capsid antigen (EBV-VCA) and EBV nuclear antigen 1 (EBNA-1)) was developed and standardized. Our assay shows a good correlation with the separate ELISAs, has a high specificity and is much more sensitive than the ELISAs. The MIA allows faster analysis of samples and can be combined with the MIA for detection of antibodies to measles, mumps, rubella and varicella zoster (MMRV) as published previously. In conclusion, the CMV-EBV MIA is a reliable assay that allows for more efficient detection of specific antibodies to CMV and EBV. This MIA therefore is especially useful for large-scale surveillance studies
- …