Downregulation of T-bet/GATA-3 ratio induced by IL-11 treatment is responsible for Th1/Th2 balance restoration in human immune thrombocytopenic purpura (ITP).

Abnormal cellular immunity induced by deranged Th1/Th2 profile has been revealed to play a critical role in the pathogenesis of immune thrombocytopenic purpura (ITP). Correction of the shifted Th1/Th2 balance represents a potential therapeutic approach to treat ITP. Here, we investigated the effects of IL-11 on the restoration of Th1/Th2 balance in the peripheral blood mononuclear cells (PBMCs) isolated from adult ITP patients. As shown here, we observed a higher ratio of T-bet/GATA-3 gene expression by quantitative real-time PCR in the PBMCs from ITP patients, consistent with the presence of an abnormally high Th1/Th2 ratio. Remarkably, upon IL-11 treatment, a reversal of T-bet/GATA-3 ratio in ITP was achieved and was shown to be responsible for the restoration of Th1/Th2 balance, with IL-11 at 100 ng/ml demonstrating the highest efficiency. T-bet and GATA-3 are the two transcriptional factors that have been indicated to be the master regulators for Th1 and Th2 lineage commitment, respectively. In the presence of 100 ng/ml IL-11, GATA-3 transcript abundance rose up to ~85-fold of that measured in untreated cells, whereas T-bet transcripts were lowered merely to ~41%, suggesting that GATA-3 was the major contributor for the reversal of T-bet/GATA-3 ratio. Thus, our findings may very well encourage the development of novel medicines that specifically target and correct the T-bet/GATA-3 imbalance identified in ITP.