• Bifidobacterium animalis AHC7 protects against pathogen-induced NF-kappaB activation in vivo

      O'Mahony, David; Murphy, Sharon; Boileau, Thomas; Park, JeanSoon; O'Brien, Frances; Groeger, David; Konieczna, Patrycja; Ziegler, Mario; Scully, Paul; Shanahan, Fergus; et al. (2010-12-22)
      Abstract Background Bifidobacteria and lactobacilli are among the early and important colonizers of the gastrointestinal tract and are generally considered to be part of a normal, healthy microbiota. It is believed that specific strains within the microbiota can influence host immune-reactivity and may play a role in protection from infection and aberrant inflammatory activity. One such strain, Bifidobacterium animalis AHC7, has been previously shown to protect against Salmonella typhimurium infection in mice and helps resolve acute idiopathic diarrhea in dogs. The aim of this study was to investigate the potential molecular and cellular mechanisms underpinning the Bifidobacterium animalis AHC7 protective effect. Results Following 4 hours of infection with Salmonella typhimurium, NF-κB activation was significantly elevated in vivo in placebo and Enterococcus faecium-fed animals while Bifidobacterium animalis AHC7 consumption significantly attenuated the NF-κB response. In vitro anti-CD3/CD28 stimulated Peyer's patch cells secreted significantly less TNF-α and IFN-γ following Bifidobacterium animalis AHC7 consumption. Stimulated cells released more IL-12p70 but this difference did not reach statistical significance. No alteration in mucosal IL-6, IL-10 or MCP-1 levels were observed. No statistically significant change in the cytokine profile of mesenteric lymph node cells was noted. In vitro, Bifidobacterium animalis AHC7 was bound by dendritic cells and induced secretion of both IL-10 and IL-12p70. In addition, co-culture of CD4+ T cells with Bifidobacterium animalis AHC7-stimulated dendritic cells resulted in a significant increase in CD25+Foxp3+ T cell numbers. Conclusion Bifidobacterium animalis AHC7 exerts an anti-inflammatory effect via the attenuation of pro-inflammatory transcription factor activation in response to an infectious insult associated with modulation of pro-inflammatory cytokine production within the mucosa. The cellular mechanism underpinning Bifidobacterium animalis AHC7 mediated attenuation of NF-κB activation may include recognition of the bacterium by dendritic cells and induction of CD25+Foxp3+ T cells.
    • Dose-related effects of vitamin D on immune responses in patients with clinically isolated syndrome and healthy control participants: study protocol for an exploratory randomized double- blind placebo-controlled trial

      O’Connell, Karen; Kelly, Siobhan; Kinsella, Katie; Jordan, Sinead; Kenny, Orla; Murphy, David; Heffernan, Eric; O’Laoide, Risteard; O’Shea, Donal; McKenna, Carmel; et al. (2013-08-27)
      Abstract Background There is increasing evidence linking vitamin D deficiency to both susceptibility to, and severity of, multiple sclerosis (MS). Patients with the clinically isolated syndrome represent the initial presentation of a demyelinating disorder, and those with asymptomatic lesions on magnetic resonance imaging (MRI) are at risk of progression to clinically definite MS. The aims of this study are to examine the immunologic effects of vitamin D in both healthy individuals and in patients with clinically isolated syndrome, and in the latter group the effects on disease progression assessed by MRI and clinical measures. Methods/Design This is a single-center double-blind randomized placebo-controlled clinical trial. The primary endpoint is the immunologic effects of two doses of vitamin D compared with placebo over 24 weeks in both healthy control participants and patients presenting with the clinically isolated syndrome. Healthy control participants (n = 39) and patients with clinically isolated syndrome (n = 45) will be randomized to one of three arms, namely 1) vitamin D 5,000 IU daily, 2) vitamin D 10,000 IU daily, or 3) placebo, and followed up for 24 weeks. In both patients and healthy control participants, the primary outcome will be immunologic measures of the frequency of CD4 T-cell subsets and cytokine responses in peripheral blood mononuclear cells, assessed at baseline, and after 16 and 24 weeks of treatment. Secondary endpoints, in the patients with clinically isolated syndrome, will be relapse activity, and the number of new T2 lesions and gadolinium-enhancing lesions assessed by MRI in the two vitamin D-treated groups compared with the placebo-treated group over the 24 weeks of the study. Trial registration EU Clinical Trials Register: EudraCT: 2012-000635-68. ClinicalTrials.gov identifier: NCT01728922
    • Image analysis as an adjunct to manual HER-2 immunohistochemical review: a diagnostic tool to standardize interpretation.

      Dobson, Lynne; Conway, Catherine; Hanley, Alan; Johnson, Alex; Costello, Sean; O'Grady, Anthony; Connolly, Yvonne; Magee, Hilary; O'Shea, Daniel; Jeffers, Michael; et al. (2010-07)
      AIMS: Accurate determination of HER-2 status is critical to identify patients for whom trastuzumab treatment will be of benefit. Although the recommended primary method of evaluation is immunohistochemistry, numerous reports of variability in interpretation have raised uncertainty about the reliability of results. Recent guidelines have suggested that image analysis could be an effective tool for achieving consistent interpretation, and this study aimed to assess whether this technology has potential as a diagnostic support tool. METHODS AND RESULTS: Across a cohort of 275 cases, image analysis could accurately classify HER-2 status, with 91% agreement between computer-aided classification and the pathology review. Assessment of the continuity of membranous immunoreactivity in addition to intensity of reactivity was critical to distinguish between negative and equivocal cases and enabled image analysis to report a lower referral rate of cases for confirmatory fluorescence in situ hybridization (FISH) testing. An excellent concordance rate of 95% was observed between FISH and the automated review across 136 informative cases. CONCLUSIONS: This study has validated that image analysis can robustly and accurately evaluate HER-2 status in immunohistochemically stained tissue. Based on these findings, image analysis has great potential as a diagnostic support tool for pathologists and biomedical scientists, and may significantly improve the standardization of HER-2 testing by providing a quantitative reference method for interpretation.
    • Influenza infection directly alters innate IL-23 and IL-12p70 and subsequent IL-17A and IFN-γ responses to pneumococcus in vitro in human monocytes.

      Loughran, Sinead T; Power, Patrick A; Maguire, Paula T; McQuaid, Samantha L; Buchanan, Paul J; Jonsdottir, Ingileif; Newman, Robert W; Harvey, Ruth; Johnson, Patricia A; Viral Immunology Laboratory, School of Nursing and Human Sciences, Dublin City University, National Institute for Biological Standards and Controls, Potters Bar, Herts, United Kingdom (Plos One, 2018-01-01)
      Influenza virus is highly contagious and poses substantial public health problems due to its strong association with morbidity and mortality. Approximately 250,000-500,000 deaths are caused by seasonal influenza virus annually, and this figure increases during periods of pandemic infections. Most of these deaths are due to secondary bacterial pneumonia. Influenza-bacterial superinfection can result in hospitalisation and/or death of both patients with pre-existing lung disease or previously healthy individuals. The importance of our research is in determining that influenza and its component haemagglutinin has a direct effect on the classic pneumococcus induced pathways to IL-17A in our human ex vivo model. Our understanding of the mechanism which leaves people exposed to influenza infection during superinfection remain unresolved. This paper demonstrates that early infection of monocytes inhibits an arm of immunity crucial to bacterial clearance. Understanding this mechanism may provide alternative interventions in the case of superinfection with antimicrobial resistant strains of bacteria.
    • Isolated anterior mediastinal tuberculosis in an immunocompetent patient

      Maguire, S.; Chotirmall, S. H; Parihar, V.; Cormican, L.; Ryan, C.; O’Keane, C; Redmond, K.; Smyth, C. (2016-02-03)
      Abstract Background The differential diagnosis of a mediastinal mass is a common challenge in clinical practice, with a wide range of differential diagnosis to be considered. One of the rarer causes is tuberculosis. Atypical presentations of tuberculosis are well documented in immunocompromised patients, but should also be considered in the immunocompetent. Case presentation This case outlines a previously healthy 22 year-old immunocompetent male presenting with worsening chest pain, positional dyspnea, dry cough and dysphagia. Chest x-ray showed evidence of an isolated anterior mediastinal mass, which was confirmed on computed tomography. A mediastinoscopy was diagnostic as histology revealed necrotizing granulomatous inflammation and the presence of acid-fast bacilli, indicating mediastinal tuberculosis. Conclusion Typically the underlying presentation of mediastinal tuberculosis is mediastinal lymphadenitis. This case was unusual in that we detected an isolated large anterior mediastinal mass accompanied by a relatively small burden of mediastinal lymphadenitis. Cases similar to this have been documented in immunosuppressed patients however in our case no evidence of immunosuppression was found. This case report emphasizes the importance that a detailed and logical pathway of investigation is pursued when encountering a mediastinal mass.
    • Self protection from anti-viral responses--Ro52 promotes degradation of the transcription factor IRF7 downstream of the viral Toll-Like receptors.

      Higgs, Rowan; Lazzari, Elisa; Wynne, Claire; Ní Gabhann, Joan; Espinosa, Alexander; Wahren-Herlenius, Marie; Jefferies, Caroline A; Molecular and Cellular Therapeutics and RSCI Research Institute, Royal College of Surgeons in Ireland, Dublin, Ireland. (2010)
      Ro52 is a member of the TRIM family of single-protein E3 ligases and is also a target for autoantibody production in systemic lupus erythematosus and Sjögren's syndrome. We previously demonstrated a novel function of Ro52 in the ubiquitination and proteasomal degradation of IRF3 following TLR3/4 stimulation. We now present evidence that Ro52 has a similar role in regulating the stability and activity of IRF7. Endogenous immunoprecipitation of Ro52-bound proteins revealed that IRF7 associates with Ro52, an effect which increases following TLR7 and TLR9 stimulation, suggesting that Ro52 interacts with IRF7 post-pathogen recognition. Furthermore, we show that Ro52 ubiquitinates IRF7 in a dose-dependent manner, resulting in a decrease in total IRF7 expression and a subsequent decrease in IFN-alpha production. IRF7 stability was increased in bone marrow-derived macrophages from Ro52-deficient mice stimulated with imiquimod or CpG-B, consistent with a role for Ro52 in the negative regulation of IRF7 signalling. Taken together, these results suggest that Ro52-mediated ubiquitination promotes the degradation of IRF7 following TLR7 and TLR9 stimulation. As Ro52 is known to be IFN-inducible, this system constitutes a negative-feedback loop that acts to protect the host from the prolonged activation of the immune response.