Does Clca1 Modulate the Innate Immune Response During Dextran Sodium Sulphate Challenge in the Murine Colon?

Does Clca1 Modulate the Innate Immune Response During Dextran Sodium Sulphate Challenge in the Murine Colon?

76 ESVP, ECVP and NSVP Proceedings 2015 J. Comp. Path. 2016, Vol. 154, 58e123 Poster Presentations Pathology of Experimental Diseases BPIFA1: A PR...

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76

ESVP, ECVP and NSVP Proceedings 2015

J. Comp. Path. 2016, Vol. 154, 58e123

Poster Presentations

Pathology of Experimental Diseases BPIFA1: A PROTEIN WITH AN IMPORTANT ROLE IN THE INFLAMMATORY RESPONSE TO VIRAL INFECTION IN THE RESPIRATORY TRACT G.H. Leeming *, N. Moyo y, K. Akram z, M. Tompkins x, G. Chapman y, T. Walsh y, L. Bingle z, C. Bingle z, R. Tripp x and J.P. Stewarty *School of Veterinary Science, yDepartment of Infection Biology, University of Liverpool, zDepartment of Infection and Immunity, University of Sheffield Medical School, University of Sheffield, UK and xDepartment of Infectious Disease, College of Veterinary Medicine, University of Georgia, USA Introduction: Bactericidal/permeability-increasing (BPI) fold-containing family-member A1 (BPIFA1), formally known as SPLUNC1, is structurally similar to BPI and other similar proteins with roles in innate immunity. BPIFA1 is expressed predominantly in the respiratory tract and has been shown to have a role in reducing inflammation and clearing pathogens in bacterial infection. Viral infection of mice with a gammaherpesvirus resulted in decreased expression of BPIFA1, with restoration of pre-infection levels coinciding with resolution of infection. Materials and Methods: We investigated the role of BPIFA1 in mice infected with different strains of influenza A virus (IAV), analyzing the temporal and spatial expression of the protein using immunohistology and image analysis software. BPIFA1 knockout mice (BPIFA1/) were infected with influenza X31 (H3N2), and histology, immunohistology, viral titre, flow cytometry and high-resolution label-free proteomic and RNAseq analysis were utilized to compare the response of BPIFA1/ to wild type mice at different time points. Results: Infection of wild type mice with different strains of IAV revealed that highly pathogenic strains were associated with decreased expression of BPIFA1 and greater inflammation. Infection of BPIFA1/ was associated with higher viral titres and a more pronounced inflammatory response, with increased numbers of B lymphocytes within perivascular infiltrates. Proteomic and RNAseq data showed changes in immune cell signalling and infiltration associated with BPIFA1, while flow cytometry indicated a role for BPIFA1 in neutrophilic inflammation. Conclusions: BPIFA1 has a role in the innate immune response to infection with IAV, which is similar to that seen in bacterial infections.

DOES CLCA1 MODULATE THE INNATE IMMUNE RESPONSE DURING DEXTRAN SODIUM SULPHATE CHALLENGE IN THE MURINE COLON? N.A. Erickson *, L. Mundhenk *, R. Glauben y, S. Giovannini *, E.E.L. Nystr€ om z, M.E.V. Johansson z and A.D. Gruber* *Institute of Veterinary Pathology, Freie Universit€at Berlin, yMedical Department, Division of Gastroenterology, Infectiology and Rheumatology, Charite, Universit€atsmedizin Berlin, Germany and zDepartment of Medical Biochemistry, University of Gothenburg, Sweden Introduction: Clca1, which is highly expressed in goblet cells, is thought to play a yet undefined role in early immune responses. It modulates the cytokine response and consecutive leucocyte recruitment in acute pneumonia and is found abundantly in the colonic mucus with an expression pattern similar to Muc2, the major structural mucus component. This study was designed to test whether Clca1 has an impact on the colonic immune response by modulating cytokine expression and/or as a structural mucus protein. Materials and Methods: Clca1-knockout (Clca1/) and wild type (WT) mice (n 5 8e10) were analyzed under na€ıve conditions and at various time points following dextran sodium sulphate (DSS) challenge via disease activity index (DAI) and histopathology. Select cytokines were quantified at the mRNA and protein levels by RTqPCR and cytometric bead array, respectively. Bacterial penetrability of the intestinal mucus barrier was characterized via antiMuc2-immunofluorescence and 16S rRNA in-situ hybridization. Results: A more than two-fold increase of Cxcl-1 and Il-17 gene expression during DSS colitis and a five-times lower IFN-g gene expression at earlier times were present in Clca1/ compared with WT mice, with no further differences between the genotypes, irrespective of challenge. Conclusions: Despite Clca1 being a major constituent of the intestinal mucus barrier, it seems to have no impact on DSS-induced mucus barrier disruption and colitis. However, it appears to play a role in cytokine regulation depending on challenge type. The significance of differential IFN-g gene expression is still unclear in light of lack of immune cell infiltration at these time points.