Effect of azitromycin on Th17/Treg balance in bronchiolitis obliterans mice after lung transplantation / 器官移植

ABSTRACT

Objective To evaluate the effect of azitromycin upon the bronchiolitis obliterans and T helper (Th)17/regulatory T cell (Treg) balance after lung transplantation. Methods Twenty-four specific pathogen free(SPF) C57BL/6 mice were used as the donors and 48 Balb/c mice were utilized as the recipients. The Balb/c mice were randomly divided into the control (C group), azitromycin control (Cazm group), transplantation (T group) and transplantation + azitromycin groups (Tazm group), 12 mice in each group. In the T and Tazm groups, heterotopic tracheal transplantation models were established to simulate bronchiolitis obliterans after lung transplantation. From 1 d post-transplantation, intragastric administration of azitromycin was given at a dose of 30 mg/kg three times per week in the Cazm and Tazm groups. At 14 and 28 d after transplantation, the transplanted trachea was removed and peripheral blood was collected. The tracheal sample was prepared for hematoxylin-eosin (HE) staining for pathological observation. The expression levels of ROR-γt and Foxp3 messenger ribonucleic acid (mRNA) in the peripheral blood were quantitatively measured by reverse transcription polymerase chain reaction (RT-PCR). The variation in the related cytokines levels of Th17 cells and Treg in the plasma was detected by enzyme linked immunosorbent assay (ELISA). Results After heterotopic tracheal transplantation, compared with the C group, thetracheal occlusion accompanied with inflammatory infiltration was observed in the T and Tazm groups. The severity of relevant symptoms in the Tazm group was slighter than that in the T group. Compared with the T group, the expression level of ROR-γt mRNA in the Tazm group was significantly down-regulated (P<0.05). No statistical significance was identified in the expression of Foxp3 mRNA between two groups (P>0.05). Compared with the T group, the levels of interleukin (IL)-6 and IL-17 cytokines in the Tazm group were significantly down-regulated (all P<0.05). Conclusions Persistent therapy of azitromycin can delay the progression of bronchiolitis obliterans after transplantation, which is probably associated with inhibiting Th17 cell differentiation and inflammation.