The host – pathogen interaction in development of post-infectious fatigue and functional gastrointestinal disorders
T cell responses, miRNA expression and antibody responses against Giardia in IBS and CFS
In 2016 the collaborative miRNA work with University of Heidelberg was almost completed. Research track student Torunn Hjøllo completed the laboratory work in the study of Giardia longitudinal antibody responses. Giardia-specific T cell responses in persons with or without sequels after Giardia infection was accepted for publication.
Antibody responses Human Giardia-specific IgG antibody responses were further examined in persons with diagnosed giardiasis, and at 6 weeks, 6 months and 12 months. Results were compared persons presumably never infected with Giardia. Results were presented at NSCMID in Rovaniemi, by our research track student Torunn Hjøllo. Research track student Matej Radunovic completed, and got approved, his særoppgave with the theme "Cloning and recombinant production of three Giardia proteins and human antibody responses". miRNA-studies (in cooperation with University of Heidelberg) A poster with preliminary results was presented at a GENIEUR meeting in Heidelberg in May, and final analyses were performed during autumn. A manuscript, describing analyses og miRNA levels in rectal epithelial cells in IBS and healthy controls is prepared for circulation in Jauary 2017, and submission in February 2017. Markers of IBS and CF in serum Sera from the Giardia cohort have been analyzed for the potential biomarkers BAFF, CdtB and flagellin antbodies as a master student project that will be finalized in May 2017. T cell responses towards Giardia Results on Giardia-specific T cell responses and cytokine responses in post-giardiasis fatigue were written up and submitted. Collaborative work on analyses of T cells in duodenal biopsies was performed with the gastroenterology department, including Vernesa Dizdar and Trygve Hausken. A manuscript is being prepared and further advanced analyses on these biopsies using CyTOF are being planned. Dissemination Posters: 1. Martinez C, Wohlfarth C, Hanevik K, Granzow M, Lasitschka F, Ralph Röth R, Dizdar V, Hausken T, Langeland N, Niesler B. Comparative miRNA Expression profiling in the intestine of Giardia-induced post-infectious IBS – a pilot study. GENIEUR meeting, Heidelberg, May 2016. 2. Hjøllo T, Bratland E, Radunovic M, Langeland N, Hanevik K. Longitudinal study of Immunoglobulin A and G responses to Giardia lamblia conserved regions of variant-specific surface protein. Accepted NSCMID, Rovaniemi, Sept 2016 3. Hanevik K, Klotz C, Brattbakk HR, Aebischer T. Developing a workflow for selecting and extracting Giardia genes of interest. Food-borne parasites meeting, Slovenia, Sept 2016. Peer-reviewed publications: Hanevik K, Kristoffersen EK, Mørch K, Rye KP, Sørnes S, Svärd S, Bruserud Ø, Langeland N. Giardia-specific cellular immune responses in post-giardiasis chronic fatigue syndrome. BMC Immunology (accepted Jan 2017) Two publications based on poster presentations 1 and 2 above are expected in 2017.
Annual report - host-pathogen interaction in development of post-infectious fatigue and functional gastrointestinal disorders
This project focuses on understanding human immune responses against the Giardia parasite, in an attempt to understand what may have caused the long term sequels observed after the 2004 Giardia outbreak in Bergen. Cellular and humoral immune responses are examined, as well as gene expression regulation in biopsies from post-giardiasis IBS patients.
Memory T cell responses towards Giardia The T cell responses against subacute and chronic giardiasis in adults have been examined by flow cytometric analyses in recently infected persons compared to persons presumably never infected with Giardia. A relatively strong IL-17 memory T cell response was found, which, in conjunction with very recent studies in calves and mice, reveals an important role for Th17 cells in the immune defenses against Giardia. The results were published in Clinical and Vaccine Immunology and elicited an editorial comment by Steven Singer, a leading expert in this field. Antibody responses Human Giardia-specific IgG antibody responses were examined with diagnosed giardiasis, and followed over a one year period. Results were compared persons presumably never infected with Giardia. Results are still being analyzed and will also be compared with antibody responses in persons referred to Haukeland University hospital with prolonged abdominal symptoms after the 2004 Giardia outbreak. Progress and preliminary results miRNA-studies (in cooperation with University of Heidelberg) Epithelial cells and lamina propria cells have been separated by laser dissection in rectal biopsies of 5 post-giardiasis IBS patients and compared to comparable material from 10 healthy volunteers. In the lamina propria, genes implicated in cell apoptosis, barrier function, mediation of immune function and cell cycle control were found to be de-regulated in the the IBS patients. In epithelial cells, genes implicated in immune response, axonal guidance, vesicular transport and barrier function were found to be de-regulated in the IBS patients. More biopsy material are available and in the coming year more IBS patients biopsy analyses will be added in this study to verify preliminary findings.
Host-pathogen intereaction in development of post-infectious fatigue and functional gastrointestinal disorders
During 2014 research has been focused at humoral and cellular immune responses to natural Giardia infection. Also progress has been made in preparing intestinal biopsy material for miRNA analysis from individuals suffering from post-infectious gastrointestinal disorders after Giardia infection.
Recruitment of recently Giardia infected persons as well as low risk controls for antigen specific T-cell responses were recruited during spring and autumn. Inclusion for cytokine analysis ended in September, and a paper is being prepared. Recruitment of some more infected individuals are undertaken to collect sera for antibody response testing. Cytokine analysis in supernatant from stimulated mononuclear cells from a previous study in the cohort of persons with long term sequels after Giardia infection have been performed and analysis will ensue in 2015. Preparation of biopsy material for miRNA pattern and pathway analysis from a previous study in individuals with post-infectious gastrointestinal disorders after Giardia infection as well as controls have been undertaken in Heidelberg using micro-dissection. This is tedious and time consuming work, expected to be finished in spring 2015. Development of an assay to measure antibody immune responses have been performed. E-coli clones expressing Giardia Variant Specific Protein have been obtained from CDC in Atlanta, USA, and protein is purified and tested as a sensitive measurement method of human IGG and IgA responses. Assays will be tested in a cohort of recently Giardia infected persons, in a cohort of exposed and unexposed children, and then applied to stored sera from patients with post-infectious fatigue and gastrointestinal disorders and controls. Conference presentations: Christina Skår Saghaug, Staffan Svärd, Steinar Sørnes, Dimitra Peirasmaki, Nina Langeland, Kurt Hanevik. Flow cytometric method for characterization of human T cell responses against Giardia lamblia. Oral presentation at IGCC in Uppsala, May 2014.
Human Memory CD4+ T Cell Immune Responses against Giardia lamblia.
Clin Vaccine Immunol 2015;23(1):11-8. Epub 2015 sep 16
Giardia-specific cellular immune responses in post-giardiasis chronic fatigue syndrome
BMC Immunology (accepted Jan 2017)