Coordinate regulation of IL-4 and IL-13 expression in human T cells: 3C analysis for DNA looping

Over 5.4 million adults receive treatment for asthma in the UK. Asthma is a chronic allergic disorder characterised by chronic inflammation. Type 2 T helper (T H 2) are an important component in the development of the asthma and the response to allergens, producing the cytokines interleukin (IL) -4 and IL-13. In T H 2 cells, production of the cytokines IL-4, IL-5, and IL-13 in a co-ordinate manner. Th2 cytokine expression is controlled by cooperation between transcription factors GATA-3 and Nuclear factor of activated T-cells -1 (NFAT1). The genes encoding these cytokines are located together the same chromosomal region, 5q31.1 in humans. We have investigated the co-ordinated expression of IL4 and IL13 in the T H 2 model cell line HUT78. Using chromatin immunoprecipitation (ChIP) and re-ChIP analysis we have shown that in HUT78 cells GATA-3 is associated with the IL4 and IL13 promoter regions. Additionally, following stimulation CD3/28 antibodies NFAT1 rapidly translocates to the nucleus and becomes associated with the promoter regions and GATA3. Finally, using Chromatin Conformation Capture (3C) we demonstrate looping of DNA at the IL4 and IL13 promoters to bring them into close proximity with each other. This suggests that the formation of a transcriptional hub under the control of GATA-3 and NF-AT drives co-ordinate T H 2 cytokine production.