Identification of helper T cell master regulator candidates using the polar score method

We develop a method we call 'polar score' to identify genes that are related to T helper cell polarization. This method is designed to identify polarizing genes in a set where many genes change expression. To illustrate the use of this technique, we apply it to published T cell microarray data and compare it to conventional analysis methods. With the new method, we find evidence for the existence of IL9 producing T cells ('Th9 cells') that are induced by a combination of TGFβ and IL4. We identify several candidate master regulator genes for this phenotype. Furthermore, treatment with TGFβ and IL12 results in a Treg and Th17 hybrid cell phenotype.