EFFECTS OF IL-4 UPON THE ACTIVITY OF STAT6 TRANSCRIPTION FACTOR IN PERIPHERAL BLOOD LYMPHOCYTES IN BRONCHIAL ASTHMA

Abstract

Abstract. The aim of the study is to specify the levels of STAT6, and phospho-STAT6 under the influence of IL-4 in patients with bronchial asthma (BA). The samples from ten healthy controls and thirty-three BA patients with allergic and non-allergic clinical forms of different severity were under investigation. Peripheral blood lymphocytes were treated with 10 ng/ml of IL-4 (Sigma Aldrich, USA) for 1 h. Then the proteins (STAT6 and phospho-STAT6) expressed in peripheral lymphocytes were analyzed by Western blot of cell lysates. Preparation of the cell lysates and Western blotting were carried out using standard procedures. Antibodies against phospho-STAT6 and STAT6 (10 ng/ml) were used (Cell Signaling, USA). Levels of thespecific proteins were standardized according to β-actin (Cell Signaling, USA). Treatment with IL-4 caused an increase of phospho-STAT6 levels in lymphocytes of all BA patients, as compared with control group. In allergic BA, the phospho-STAT6 levels were significantly higher than in non-allergic clinical forms. Expression of STAT6 in lymphocytes of patients with severe BA was significantly higher, as compared to BA of moderate severity. An IL-4-induced activation of the STAT6 transcription factor was revealed in an in vitro system, being mostly expressed in allergic BA. The level of STAT6 may serve as a BA severity index. This study was supported by a «Scholarship of the Year» grant from the St. Petersburg State Medical I. Pavlov University (2007).

Keywords

• bronchial asthma
• jak-stat-system
• il-4
• stat6
• pstat6
• lymphocytes