Abstract:

TH17/Treg are common immune substances between lung and large intestine.  To explore the immune mechanism of "interior-exterior relationship between lung and large intestine",  the study has observed the changes of TH17/Treg in the rat model with bronchial asthma (asthma) and lung-intestinal disease.  Asthma group,  lung-intestinal disease group,  and Dachengqi decoction group of rat models were established.  Dachengqi decoction group was divided into asthma intervention group and lung-intestinal disease intervention group.  The distribution and expression of Th17 and Treg subsets in peripheral blood lymphocytes and the levels of IL-17,  IL-6 and IL-2 in serum of rats in each group were detected.  The results showed that,  compared with the normal control group,  the proportion of Th17 cells increased and that of Treg cells decreased,  IL-6 and IL-17 levels increased and IL-2 levels decreased in serum of asthma group and lung-intestinal disease group (P<0.005),  especially in lung-intestinal disease group (P<0.005).  With the intervention of Dachengqi decoction,  compared with asthma group,  the proportion of Th17 cells decreased,  that of Treg cells increased,  the levels of IL-6 and IL-17 decreased,  and the level of IL-2 increased in serum of asthma intervention group and lung-intestinal disease intervention group (P<0.005).  It can be concluded that the changes of intestinal immune function may lead to imbalance of TH17/Treg in asthma.  Migration of immune response to respiratory mucosa and other parts can aggravate the onset of asthma.  Dachengqi decoction can alleviate asthma by regulating intestinal TH17/Treg immunity,  which can improve the mucosal barrier function and reduce lymphocyte "homing".

Key words: bronchial asthma, lung-intestinal disease, TH17/Treg, Dachengqi decoction