[Intestinal dysbacteriosis promotes intestinal intraepithelial T lymphocyte activation and proinflammatory cytokine secretion in mice].

Objective To study the effect of intestinal dysbacteriosis on mouse intestinal intraepithelial T lymphocytes (iIELs). Methods The intestinal dysbacteriosis was induced in mice by oral administration of ceftriaxone sodium. The iIELs were digested with ethylene diaminetetraacetic acid (EDTA) and DL-dithiothreitol (DTT). The phenotype of iIELs and the proportions of subsets of T cells were detected by flow cytometry; the concentrations of cytokines (IL-2, IL-6, IFN-γ) in the intestine were examined by ELISA; the intestinal bacteria were analyzed with selective medium and PCR. Results Compared with the control group, intestinal commensal bacteria in mice were significantly reduced after the administration of ceftriaxone sodium, but fungi and yeasts increased. The proportions of T cell subgroups in ilELs changed, in which the proportion of TCR γδ(+)T cells significantly increased, and the activated CD3(+)T, CD8(+)T and TCR γδ(+)T cells increased. The concentrations of IL-2, IL-6 and IFN-γ were significantly raised in the intestine. Conclusion The dysbacteriosis results in the decrease of commensal bacteria, the increase of the fungus, the damage of microbial barrier, the more activated T cells in ilELs and the promotion of proinflammatory cytokine secretion in the gut. This is probably one of the reasons for inflammatory bowel disease caused by dysbacteriosis.

[Shengqifuzheng Injection promotes the recovery of B cells in gut-associated lymphoid tissues of mice treated with cyclophosphamide].

Objective To investigate the effect of Shengqifuzheng Injection (SQFZ) on the number recovery of B cells in gut-associated lymphoid tissues (GALTs) of mice receiving cyclophosphamide-based chemotherapy. Methods BALB/c mice were randomly divided into control group, cyclophosphamide (Cy) group and SQFZ group. Mice in Cy group and SQFZ group were injected intraperitoneally with Cy (100 mg/kg), while the control mice were injected with an equal volume of normal saline. Twenty-four hours later, mice in SQFZ group were administrated intragastricly with 1 mL SQFZ once daily for 10 consecutive days, and mice in the other groups were given the same volume of normal saline. Body mass of all the mice was measured every day. Mice were killed on day 10, and the indexes of spleen and thymus were measured. Cell cycles of bone marrow cells and the percentage of B cells in lymphocytes in mesenteric lymph node (MLN) and Peyer's patch (PP) were detected by flow cytometry. In vitro, after being treated with SQFZ, activity of lymphocytes was evaluzed by MTT assay; expression of CD86 on B cell surface was analyzed by flow cytometry; and B cell proliferation was tested by carboxyfluorescein succinimidyl ester (CFSE)-based lymphocyte proliferation assay. Results SQFZ alleviated the loss of body mass caused by Cy and promoted the recovery of thymus indexes, spleen indexes and B cell number in MLN and PP. But it did not alleviate the bone marrow suppression of mice in this condition. In vitro, SQFZ enhanced lymphocyte activity, and improved the activation and proliferation of B cells. Conclusion SQFZ could accelerate the recovery of B cells in GALTs of mice receiving chemotherapy and it might act by promoting B cell proliferation.