title: Responses of Bovine Innate Immunity to Mycobacterium avium subsp. paratuberculosis Infection Revealed by Changes in Gene Expression and Levels of MicroRNA.
abstract: Paratuberculosis in cattle is a chronic granulomatous gastroenteritis caused by Mycobacterium avium subsp. paratubercolosis (MAP) which is endemic worldwide. In dairy herds, it is responsible for huge economic losses. However, current diagnostic methods do not detect subclinical infection making control of the disease difficult. The identification of MAP infected animals during the sub-clinical phase of infection would play a key role in preventing the dissemination of the pathogen and in reducing transmission. Gene expression and circulating microRNA (miRNA) signatures have been proposed as biomarkers of disease both in the human and veterinary medicine. In this paper, gene expression and related miRNA levels were investigated in cows positive for MAP, by ELISA and culture, in order to identify potential biomarkers to improve diagnosis of MAP infection. Three groups, each of 5 animals, were used to compare the results of gene expression from positive, exposed and negative cows. Overall 258 differentially expressed genes were identified between unexposed, exposed, but ELISA negative and positive groups which were involved in biological functions related to inflammatory response, lipid metabolism and small molecule biochemistry. Differentially expressed miRNA was also found among the three groups: 7 miRNAs were at a lower level and 2 at a higher level in positive animals vs unexposed animals, while 5 and 3 miRNAs were respectively reduced and increased in the exposed group compared to the unexposed group. Among the differentially expressed miRNAs 6 have been previously described as immune-response related and two were novel miRNAs. Analysis of the miRNA levels showed correlation with expression of their target genes, known to be involved in the immune process. This study suggests that miRNA expression is affected by MAP infection and play a key role in tuning the host response to infection. The miRNA and gene expression profiles may be biomarkers of infection and potential diagnostic of MAP infection earlier than the current ELISA based diagnostic tests.
authors.affiliation: Parco Tecnologico Padano, Lodi, Italy.|Department of Veterinary Medicine, University of Milan, Milan, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Malvisi
authors.affiliation: Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy.
authors.forename: Fiorentina
authors.identifier: http://orcid.org/0000-0003-4001-2623
authors.initials: F
authors.lastname: Palazzo
authors.affiliation: Parco Tecnologico Padano, Lodi, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Morandi
authors.affiliation: Parco Tecnologico Padano, Lodi, Italy.|Institute of Agricultural Biology and Biotechnology, National Research Council, Lodi, Italy.
authors.forename: Barbara
authors.identifier: http://orcid.org/0000-0002-9558-914X
authors.initials: B
authors.lastname: Lazzari
authors.affiliation: Parco Tecnologico Padano, Lodi, Italy.|School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, Australia.
authors.forename: John L
authors.identifier: http://orcid.org/0000-0001-5188-7957
authors.initials: JL
authors.lastname: Williams
authors.affiliation: Department of Veterinary Medicine, University of Milan, Milan, Italy.
authors.forename: Giulio
authors.identifier: http://orcid.org/0000-0002-5013-5179
authors.initials: G
authors.lastname: Pagnacco
authors.affiliation: Department of Veterinary Medicine, University of Milan, Milan, Italy.
authors.forename: Giulietta
authors.identifier: http://orcid.org/0000-0001-5188-7957
authors.initials: G
authors.lastname: Minozzi
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000235:genetics / Q000276:immunology*; D003612:Dairying; D020869:Gene Expression Profiling; D053263:Gene Regulatory Networks; D007113:Immunity, Innate; D035683:MicroRNAs / Q000097:blood*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000502:physiology*; D010283:Paratuberculosis / Q000097:blood / Q000235:genetics / Q000276:immunology*
chemical_list: D015415:Biomarkers; D035683:MicroRNAs