B Cell Activating Transcription Factor Regulates Acute Airway Inflammation in Asthmatic Mice

Abstract

To investigate the regulatory effect of В cell activating transcription factor (BATF) on acute airway inflammation and its association with retinoic acid orphan nuclear receptors gammat (RORyt) in asthmatic mice. Methods 24 female BALB/c mice were randomly and equally divided into three groups (// = 8): normal saline (NS) treated» asthma (AS) control and dexamethasone (DEX) treated. AS mice were sensitized and challenged with OVA to establish murine asthma model. Histological changes in lung tissues of the mice were observed by HE staining. Numbers of white blood cell (WBC), polymorphonuclear leukocyte (PMN) and eosinophils (EOS) in the bronchoalveolar lavage fluid (BALF) of the mice were counted. The concentration of interleukin-17 (IL-17) in BALF was measured by ELISA. Quantitative real-time PCR (RT-PCR) was performed to assess the mRNA expressions of BATF, IL-17 and RORyt in the lung tissues. Results The HE staining showed a higher level of inflammatory cell infiltration around the bronchi of AS mice compared with those treated with NS, predominantly in the forms of EOS, PMN and lymphocytes. The AS and DEX treated mice had higher levels of EOS, PMN, WBC and mRNA expressions of BATF. IL-17 and RORyt in BALF than those treated with NS (P< 0.05). DEX reduced the levels of EOS, PMN, WBC and IL-17 in BALF significantly (P< 0. 05). The mRNA expression of BATF in lung tissues of mice was positively correlated with the expression of IL- 17, RORyt and the counts of WBC,EOS and PMN in BALF (P<0. 05). Conclusion Asthmatic mice have increased expressions of BATF, IL-17 and ROR yt in bronchial and lung tissues. BATF can, through regulating the secretion of Thl7 cells, readjust the airway inflammatory. The regulatory function may take effect through synergy with RORyt .

Keywords: Asthma IL-17, BATF, The airway inflammation