[Alterations in intestinal microflora balance induce maturity and increase the expressions of TLR2 and TLR4 of dendritic cells in mouse lung].

OBJECTIVE

To observe the effect of intestinal microflora imbalance caused by antibiotics on the maturity of dendritic cells (DCs) and the expressions of Toll-like receptor 2 (TLR2), TLR4 on DCs in the lung of ovalbumin (OVA)-induced asthma mice.

METHODS

Sixty-four 3-week-old female BALB/c mice were divided randomly into 4 groups, i.e. microbiota imbalance group, microbiota imbalamce combined with OVA challenge group, OVA challenge group and control group, with sixteen mice in each group. On day 14, flow cytometry was adopted to measure the DC subtypes and maturity (MHC-II molecules), and the expressions of TLR2, TLR4 on DCs. The expressions of transforming growth factor-β1 (TGF-β1) and interleukin-6 (IL-6) in situ in lung were detected by immunohistochemical staining. The levels of TGF-β1 and IL-6 in bronchoalveolar lavage fluid (BALF) were examined by ELISA.

RESULTS

Compared with control group and OVA challenge group, MHC-II molecules and TLR2, TLR4 expressions on DCs in the lung increased in both microbiota imbalance combined with OVA challenge group and microbiota imbalance group, but they were not significantly different between the two groups (P>0.05). Compared with the other three groups, microbiota imbalance combined with OVA challenge group showed the up-regulated expressions of TGF-β1 and IL-6 proteins in lung and BALF.

CONCLUSION

The alterations in intestinal microflora balance promoted the maturity of DCs and raised the expressions of TLR2 and TLR4 on DCs in mouse lung.