Bu-Shen-Fang-Chuan formula attenuates T-lymphocytes recruitment in the lung of rats with COPD through suppressing CXCL9/CXCL10/CXCL11-CXCR3 axis

Abstract

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease characterized by irreversible airflow limitation. The current medications show limited effects on the decline of pulmonary function in COPD. Our multicenter clinical trial found that Bu-Shen-Fang-Chuan fomula (BSFCF), a Chinese herbal formula, markedly reduced the frequencies of acute exacerbation of COPD and delayed lung function decline. However, the underlying mechanisms are still unclear. In this study, we established a COPD rat model through a 6-month exposure to cigarette smoke (CS) and found that BSFCF (7.2 g/kg) effectively improved CS-induced reduction in pulmonary function and remarkably decreased the numbers of inflammatory cells in bronchoalveolar lavage fluid (BALF). Importantly, BSFCF treatment notably prevented the accumulation of T-lymphocytes (especially CD8⁺ T-cells) in the lung of COPD rats. RNA sequencing analysis of lung tissue demonstrated that CXCL9/CXCL10/CXCL11-CXCR3 chemokine axis in the lung of CS-exposed rats was significantly suppressed by BSFCF. Moreover, our Real-time PCR data verified that BSFCF evidently inhibited the mRNA expressions of CXCL9, CXCL10, CXCL11 and CXCR3. Conclusively, BSFCF markedly improved pulmonary function and attenuated CD8⁺ T-cells recruitment in the lung of CS-exposed rats, which were partially through inhibition of CXCL9/CXCL10/CXCL11-CXCR3 axis.

Keywords: BSFCF; CD8; COPD; CXCR3; T-cells.