AUTHOR=Zhou Cui , Chen Ling-Ling , Lu Rui-Qi , Ma Wei-Wei , Xiao Rong 

TITLE=Alteration of Intestinal Microbiota Composition in Oral Sensitized C3H/HeJ Mice Is Associated With Changes in Dendritic Cells and T Cells in Mesenteric Lymph Nodes

JOURNAL=Frontiers in Immunology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.631494

DOI=10.3389/fimmu.2021.631494

ISSN=1664-3224

ABSTRACT=<p>This research aimed to investigate the allergic reaction of C3H/HeJ mice after sensitization with ovalbumin (OVA) without any adjuvant and to analyze the association between intestinal microbiota and allergy-related immune cells in mesenteric lymph nodes (MLN). The allergic responses of C3H/HeJ mice orally sensitized with OVA were evaluated, and immune cell subsets in spleen and MLN and cytokines were also detected. The intestinal bacterial community structure was analyzed, followed by Spearman correlation analysis between changed gut microbiota species and allergic parameters. Sensitization induced a noticeable allergic response to the gavage of OVA without adjuvant. Increased levels of Th2, IL-4, CD103<sup>+</sup>CD86<sup>+</sup> DC, and MHCII<sup>+</sup>CD86<sup>+</sup> DC and decreased levels of Th1, Treg, IFN-γ, TGF-β1, and CD11C<sup>+</sup>CD103<sup>+</sup> DC were observed in allergic mice. Furthermore, families of <italic>Lachnospiraceae</italic>, <italic>Clostridiaceae_1</italic>, <italic>Ruminococcaceae</italic>, and <italic>peprostreptococcaceae</italic>, all of which belonging to the order <italic>Clostridiales</italic>, were positively related to Treg and CD11C<sup>+</sup>CD103<sup>+</sup> DC, while they were negatively related to an allergic reaction, levels of Th2, CD103<sup>+</sup>CD86<sup>+</sup> DC, and MHCII<sup>+</sup>CD86<sup>+</sup> DC in MLN. The family of <italic>norank_o_Mollicutes_RF39</italic> belonging to the order <italic>Mollicutes_RF39</italic> was similarly correlated with allergic reaction and immune cells in MLN of mice. To sum up, allergic reactions and intestinal flora disturbances could be induced by OVA oral administration alone. The orders of <italic>Clostridiales</italic> and <italic>Mollicutes_RF39</italic> in intestinal flora are positively correlated with levels of Treg and CD11C<sup>+</sup>CD103<sup>+</sup> DC in MLN of mice.</p>