Orally administered extract from \u3ci\u3ePrunella vulgaris\u3c/i\u3e attenuates spontaneous colitis in mdr1a\u3csup\u3e-/-\u3c/sup\u3e mice

AIM: To investigate the ability of a Prunella vulgaris (P. vulgaris) ethanolic extract to attenuate spontaneous typhlocolitis in mdr1a-/- mice. METHODS: Vehicle (5% ethanol) or P. vulgaris ethanolic extract (2.4 mg/d) were administered daily by oral gavage to mdr1a-/- or wild type FVBWT mice from 6 wk of age up to 20 wk of age. Clinical signs of disease were noted by monitoring weight loss. Mice experiencing weight loss in excess of 15% were removed from the study. At the time mice were removed from the study, blood and colon tissue were collected for analyses that included histological evaluation of lesions, inflammatory cytokine levels, and myeloperoxidase activity. RESULTS: Administration of P. vulgaris extracts to mdr1a-/- mice delayed onset of colitis and reduced severity of mucosal inflammation when compared to vehicle-treated mdr1a-/- mice. Oral administration of the P. vulgaris extract resulted in reduced (P \u3c 0.05) serum levels of IL-10 (4.6 ± 2 vs 19.4 ± 4), CXCL9 (1319.0 ± 277 vs 3901.0 ± 858), and TNFα (9.9 ± 3 vs 14.8 ± 1) as well as reduced gene expression by more than two-fold for Ccl2, Ccl20, Cxcl1, Cxcl9, IL-1 α, Mmp10, VCAM-1, ICAM, IL-2, and TNFα in the colonic mucosa of mdr1a-/- mice compared to vehicle-treated mdr1a-/- mice. Histologically, several microscopic parameters were reduced (P \u3c 0.05) in P. vulgaris -treated mdr1a-/- mice, as was myeloperoxidase activity in the colon (2.49 ± 0.16 vs 3.36 ± 0.06, P \u3c 0.05). The numbers of CD4+ T cells (2031.9 ± 412.1 vs 5054.5 ± 809.5) and germinal center B cells (2749.6 ± 473.7 vs 4934.0 ± 645.9) observed in the cecal tonsils of P. vulgaris - treated mdr1a-/- were significantly reduced (P \u3c 0.05) from vehicle-treated mdr1a-/- mice. Vehicle-treated mdr1a-/- mice were found to produce serum antibodies to antigens derived from members of the intestinal microbiota, indicative of severe colitis and a loss of adaptive tolerance to the members of the microbiota. These serum antibodies were greatly reduced or absent in P. vulgaris -treated mdr1a-/- mice. CONCLUSION: The anti-inflammatory activity of P. vulgaris ethanolic extract effectively attenuated the severity of intestinal inflammation in mdr1a-/- mice

Non-Canonicaly Recruited TCRαβCD8αα IELs Recognize Microbial Antigens

In the gut, various subsets of intraepithelial T cells (IELs) respond to self or non-self-antigens derived from the body, diet, commensal and pathogenic microbiota. Dominant subset of IELs in the small intestine are TCRαβCD8αα+ cells, which are derived from immature thymocytes that express self-reactive TCRs. Although most of TCRαβCD8αα+ IELs are thymus-derived, their repertoire adapts to microbial flora. Here, using high throughput TCR sequencing we examined how clonal diversity of TCRαβCD8αα+ IELs changes upon exposure to commensal-derived antigens. We found that fraction of CD8αα+ IELs and CD4+ T cells express identical αβTCRs and this overlap raised parallel to a surge in the diversity of microbial flora. We also found that an opportunistic pathogen (Staphylococcus aureus) isolated from mouse small intestine specifically activated CD8αα+ IELs and CD4+ derived T cell hybridomas suggesting that some of TCRαβCD8αα+ clones with microbial specificities have extrathymic origin. We also report that CD8ααCD4+ IELs and Foxp3CD4+ T cells from the small intestine shared many αβTCRs, regardless whether the later subset was isolated from Foxp3CNS1 sufficient or Foxp3CNS1 deficient mice that lacks peripherally-derived Tregs. Overall, our results imply that repertoire of TCRαβCD8αα+ in small intestine expends in situ in response to changes in microbial flora

Orally administered extract from \u3ci\u3ePrunella vulgaris\u3c/i\u3e attenuates spontaneous colitis in mdr1a\u3csup\u3e-/-\u3c/sup\u3e mice

AIM: To investigate the ability of a Prunella vulgaris (P. vulgaris) ethanolic extract to attenuate spontaneous typhlocolitis in mdr1a-/- mice. METHODS: Vehicle (5% ethanol) or P. vulgaris ethanolic extract (2.4 mg/d) were administered daily by oral gavage to mdr1a-/- or wild type FVBWT mice from 6 wk of age up to 20 wk of age. Clinical signs of disease were noted by monitoring weight loss. Mice experiencing weight loss in excess of 15% were removed from the study. At the time mice were removed from the study, blood and colon tissue were collected for analyses that included histological evaluation of lesions, inflammatory cytokine levels, and myeloperoxidase activity. RESULTS: Administration of P. vulgaris extracts to mdr1a-/- mice delayed onset of colitis and reduced severity of mucosal inflammation when compared to vehicle-treated mdr1a-/- mice. Oral administration of the P. vulgaris extract resulted in reduced (P \u3c 0.05) serum levels of IL-10 (4.6 ± 2 vs 19.4 ± 4), CXCL9 (1319.0 ± 277 vs 3901.0 ± 858), and TNFα (9.9 ± 3 vs 14.8 ± 1) as well as reduced gene expression by more than two-fold for Ccl2, Ccl20, Cxcl1, Cxcl9, IL-1 α, Mmp10, VCAM-1, ICAM, IL-2, and TNFα in the colonic mucosa of mdr1a-/- mice compared to vehicle-treated mdr1a-/- mice. Histologically, several microscopic parameters were reduced (P \u3c 0.05) in P. vulgaris -treated mdr1a-/- mice, as was myeloperoxidase activity in the colon (2.49 ± 0.16 vs 3.36 ± 0.06, P \u3c 0.05). The numbers of CD4+ T cells (2031.9 ± 412.1 vs 5054.5 ± 809.5) and germinal center B cells (2749.6 ± 473.7 vs 4934.0 ± 645.9) observed in the cecal tonsils of P. vulgaris - treated mdr1a-/- were significantly reduced (P \u3c 0.05) from vehicle-treated mdr1a-/- mice. Vehicle-treated mdr1a-/- mice were found to produce serum antibodies to antigens derived from members of the intestinal microbiota, indicative of severe colitis and a loss of adaptive tolerance to the members of the microbiota. These serum antibodies were greatly reduced or absent in P. vulgaris -treated mdr1a-/- mice. CONCLUSION: The anti-inflammatory activity of P. vulgaris ethanolic extract effectively attenuated the severity of intestinal inflammation in mdr1a-/- mice