THE ROLE OF TH9 CELLS AND THEIR TRANSCRIPTION FACTORS STAT6 AND PU.1 IN ASTHMA

Abstract

Asthma is a common chronic inflammatory disease of the airways characterized by variable and reccuring symptoms, reversible airflow obstruction and bronchospasm. Asthma is caused by a combination of complex and incompletely understood environmental and genetic interactions. Common symptoms include wheezing, coughing, chest tightness and shortness of breath. Th9 cells are novel identified subest of CD4+ T helper cells, which could contribute to airway inflammation in allergic asthma. Th9 cells are a distinct subpopulation of CD4+ effector T cell that preferntially secretes high levels of IL-9. Naive CD4+ T cells differentiate into Th9 cells in the presence of TGF-β and IL-4. These cytokines induce expression of the transcription factors PU.1 and STAT6 (by Interferon Regulatory Factor 4 (IRF4), which subseqently regulate expression of the Il9 gene. Th9 cells play important role in defense against parasitic helminth infections and allergic inflammation, airway remodeling, and autoimune disease.