[E.faecium QH06 alleviates TNBS-induced colonic mucosal injury in rats]

OBJECTIVE

To investigate the effect of Enterococcus faecium QH06 on TNBS-induced ulcerative colitis (UC) in rats and explore the mechanisms in light of intestinal flora and intestinal immunity.

METHODS

Thirty-six male Wistar rats were randomized equally into control group, UC model group, and E.faecium QH06 intervention group. The rats in the latter two groups were subjected to colonic enema with 5% TNBS/ethanol to induce UC, followed by treatment with intragastric administration of distilled water or E.faecium QH06 at the dose of 0.21 g/kg. After 14 days of treatment, the rats were examined for colon pathologies with HE staining. The mRNA and protein expression levels of IL-4, IL-10, IL-12, and IFN-γ in the colon tissues were detected using RT-qPCR and ELISA, and the expression of TLR2 protein was detected with immunohistochemistry and ELISA. Illumina Miseq platform was used for sequencing analysis of the intestinal flora of the rats with bioinformatics analysis. The correlations of the parameters of the intestinal flora with the expression levels of TLR2 and cytokines were analyzed.

RESULTS

The rats with TNBS- induced UC showed obvious weight loss (P < 0.01) and severe colon tissue injury with high pathological scores (P < 0.01). The protein expression levels of IFN-γ, IL-12, and TLR2 (P < 0.01) and the mRNA expression levels of IFN-γ, IL-12 and IL-10 (P < 0.05) were significantly increased in the colon tissues of the rats with UC. Illumina Miseq sequence analysis showed that in UC rats, the Shannon index (P < 0.05) ACE (P < 0.01)and Chao (P < 0.05) index for the diversity of intestinal flora both decreased with a significantly increased abundance of Enterobacteriaceae (P < 0.01) and a lowered abundance of Burkholderiaceae (P < 0.05). Compared with the UC rats, the rats treated with E. faecium QH06 showed obvious body weight gain (P < 0.05), lessened colon injuries, lowered pathological score of the colon tissue (P < 0.05), decreased protein expressions of IFN- γ, IL- 12, and TLR2 and mRNA expressions of IFN- γ and IL-12 (P < 0.01 or 0.05), and increased protein expressions of IL- 4 (P < 0.05). The Shannon index ACE (P < 0.05) and Chao (P < 0.05) index of intestinal microflora were significantly increased, the abundance of Enterobacteriaceae was lowered and that of Burkholderiaceae and Rikenellaceae was increased in E.faecium QH06- treated rats (P < 0.01 or 0.05). Correlation analysis showed that IFN-γ was positively correlated with the abundance of Enterobacteriaceae, and IFN-γ was negatively correlated with the abundance of Prevotellaceae, Desulfovibrionaceae, norank_o_Mollicutes_RF39 and Clostridiales_vadinBB60_group; TLR2 was negatively correlated with Clostridiales_vadinBB60_group, norank_o_Mollicutes_RF39 and Prevotellaceae.

CONCLUSION

E.faecium QH06 can alleviate TNBS-induced colonic mucosal injury in rats, and its effect is mediated possibly by increasing the abundance of SCFA-producing bacteria such as Prevotellaceae and inhibiting abnormal immune responses mediated by TLR2.

[Cervial vestibular-evoked myogenic potential induced by galvanic vestibular stimulation in normal people]

Objective:To establish a new method for detecting vestibular function by testing cervical vestibular-evoked myogenic potential induced by galvanic vestibular stimulation in normal population. Method:Twenty normal ears were tested for cervical vestibular evoked myogenic potential induced by galvanic vestibular stimulation. SPSS 18.0 software was used to analyze the obtained data. Result:In all healthy subjects mastoid-forehead galvanic vestibular stimulation produced a positive-negative biphasic EMG responses on SCM ipsilateral to the cathodal electrode. The latency of p13 was（11.52±3.05） ms. The latency of n23 was（15.31±3.38） ms. The amplitude of p13-n23 was（40.55±27.93） μV. The interval of p13-n23 was（3.53±1.38） ms. The interaural asymmetry ratio（AR, %） of p13, n23 latency, the amplitude and interval were respectively（6.96±6.79）%, （6.47±5.93）%, （28.08±26.42）% and （16.61±11.11）%. There was no significant difference in all parameters between the right and left ears of all subjects. Conclusion:The value of cervical vestibular-evoked myogenic potential induced by galvanic vestibular stimulation in normal subjects can be established to explore methods for diagnosis, treatment and researching mechanism of auditory neuropathy and vestibular neuropathy.

[Construction of specific artificial antigen-presenting cells for in vitro activation of CD19 chimeric antigen receptor T cells]

OBJECTIVE

To construct CD19-specific artificial antigen-presenting cells (aAPCs) for in vitro activation and expansion of CD19 chimeric antigen receptor (CAR)-modified T cells (CD19-CAR-T) and investigate their cytotoxic effect.

METHODS

CD19-specific aAPCs (NIH3T3-CD19/86, NIH3T3-CD19/86/137L) expressing costimulatory molecules CD86 and/or CD137L were prepared on the basis of NIH3T3 backbone cells by lentivirus-mediated gene transfer. Irradiated CD19-specific aAPCs were co-cultured with CD19-CAR-T cells to activate and amplify CD19-CAR-T cells. The growth curve of CD19-CAR-T cells was determined by trypan blue exclusion assay, and CD19CAR expression and phenotype on CD19-CAR-T cells were detected by flow cytometry. The in vitro cytotoxicity of CD19-CAR-T cells against the target cells was evaluated by bioluminescence-based cytotoxicity assay.

RESULTS

Flow cytometry showed that NIH3T3-CD19/86 and NIH3T3-CD19/86/137L expressed high levels of CD19, CD86 and/or CD137L. Both NIH3T3-CD19/86 and NIH3T3-CD19/86/137L cells could amplify CD19-CAR-T cells efficiently, but NIH3T3-CD19/86/137L cells had better amplification effect. After 14 days of co-culture with NIH3T3-CD19/86/137L cells, the number of CD19-CAR-T cells was significantly greater than that of NIH3T3-CD19/86 cells (P<0.05), and the proportion of CD19-CAR-T cells in the total T cells increased significantly (P<0.05). CD19-CAR-T cells amplified by CD19-specific aAPCs produced target-specific cytotoxicity and were able to specifically kill CD19-positive target cells. About 20% central memory T cells were present in the final products expanded by NIH3T3-CD19/86/137L.

CONCLUSION

We successfully prepared CD19-specific aAPCs that can specifically amplify functional CD19-CART cells in vitro, which facilitates the acquisition of clinical-scale high-quality CD19-CART cells.