Bifidobacterium longum CECT 7347 Modulates Immune Responses in a Gliadin-Induced Enteropathy Animal Model

Coeliac disease (CD) is an autoimmune disorder triggered by gluten proteins (gliadin) that involves innate and adaptive immunity. In this study, we hypothesise that the administration of Bifidobacterium longum CECT 7347, previously selected for reducing gliadin immunotoxic effects in vitro, could exert protective effects in an animal model of gliadin-induced enteropathy. The effects of this bacterium were evaluated in newborn rats fed gliadin alone or sensitised with interferon (IFN)-γ and fed gliadin. Jejunal tissue sections were collected for histological, NFκB mRNA expression and cytokine production analyses. Leukocyte populations and T-cell subsets were analysed in peripheral blood samples. The possible translocation of the bacterium to different organs was determined by plate counting and the composition of the colonic microbiota was quantified by real-time PCR. Feeding gliadin alone reduced enterocyte height and peripheral CD4+ cells, but increased CD4+/Foxp3+ T and CD8+ cells, while the simultaneous administration of B. longum CECT 7347 exerted opposite effects. Animals sensitised with IFN-γ and fed gliadin showed high cellular infiltration, reduced villi width and enterocyte height. Sensitised animals also exhibited increased NFκB mRNA expression and TNF-α production in tissue sections. B. longum CECT 7347 administration increased NFκB expression and IL-10, but reduced TNF-α, production in the enteropathy model. In sensitised gliadin-fed animals, CD4+, CD4+/Foxp3+ and CD8+ T cells increased, whereas the administration of B. longum CECT 7347 reduced CD4+ and CD4+/Foxp3+ cell populations and increased CD8+ T cell populations. The bifidobacterial strain administered represented between 75–95% of the total bifidobacteria isolated from all treated groups, and translocation to organs was not detected. These findings indicate that B. longum attenuates the production of inflammatory cytokines and the CD4+ T-cell mediated immune response in an animal model of gliadin-induced enteropathy

Leukocyte percentages (%) in peripheral blood of different rat experimental groups.

<p>The results are expressed as mean ± SD (n = 6).</p>a-e<p>Superscript letters in a same row indicate statistically (<i>P</i><0.05) significant differences between the pair of samples that has the same letter as determined applying the Student <i>t</i> test (*).</p><p>* <i>P</i> values: a, 0.028; b, 0.039; c, 0.005; d, 0.048; e, 0.048.</p

Phenotyping of lymphocyte populations in peripheral blood of rats after different treatments.

<p>The results are expressed as mean ± standard deviation (n = 6). *Indicates statistically significant (<i>P</i><0.05) differences relative to the controls; bars indicate significant differences between the specific pair comparisons as determined by applying the Student <i>t</i> test.</p

Tumour necrosis factor (TNF)-α and interleukine (IL)-10 production in jejunal tissue sections of rats after different treatments.

<p>The results are expressed as mean ± standard deviation (n = 6). *Indicates statistically significant (<i>P</i><0.05) differences compared to the controls; bars indicate significant differences between the specific pair comparisons as determined by applying the Student <i>t</i> test.</p

Histology of jejunal tissue sections of different experimental rat groups, stained with hematoxylin-eosin showing the different degree of cellular infiltration in the lamina propria of animals sensitized or not with IFN-γ and fed gliadins and <i>B. longum</i> CECT 7347.

<p>Scale bar, 100 µm.</p

Morphometric evaluation of jejunal sections.

<p>The results are expressed as mean ± standard deviation of 20 independent microscopic fields of each animal (n = 6).</p>a-l<p>Superscript letters in the same row indicate statistically significant (<i>P</i><0.05) differences between the pair of samples that has the same letter as determined applying the Student <i>t</i> test (*).</p>1<p>Number of cells in a surface of 20 µm² at the lamina propria;</p>2<p>Number of enterocytes a long 20 µm at the luminal side of the intestinal epithelia.</p><p>* <i>P</i> values: a, 0.050; b, 0.004; c, 0.020; d, 0.016; e, 0.004; f, 0.001; g, 0.007; h, 0.043; i, 0.014; j, 0.033; k, 0.005; l, 0.005; m, 0.001; n, 0.001.</p

Expression (mRNA) of nuclear factor kappa B (NFκB) in jejunal sections of rats after different treatments.

<p>The results are expressed as mean ± standard deviation (n = 6). *Indicates statistically significant (<i>P</i><0.05) differences relative to the controls; bars indicate significant differences between the specific pair comparisons as determined by applying the Student <i>t</i> test.</p

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data