Imbalanced expression of human Tim-1 and Tim-3 in peripheral blood mononuclear cells from immune thrombocytopenia patients

Abstract

The T-cell immunoglobulin and mucin domain-(Tim)-1 molecule and Tim-3 are mainly expressed on activated T helper (Th) 2 and Th1 cells, respectively, and have been implicated in the pathogenesis of some autoimmune diseases. Immune thrombocytopenia (ITP) is a common autoimmune disorder, and the complex dysregulation of cellular immunity has been observed; however, the relationship between Tims and excessive immune responses in ITP remains unclear. Using real-time quantitative polymerase chain reaction (RT-PCR), the mRNA expression levels of Tim-1, Tim-3, T-box transcription factor (T-bet) and GATA binding protein 3 (GATA-3) were measured in the peripheral blood mononuclear cells (PBMCs) of 45 newly diagnosed patients with active ITP, 34 ITP patients in remission and 31 healthy volunteers. Tim-3 mRNA expression in PBMCs in newly diagnosed patients was significantly decreased. At the same time, Tim-1 mRNA was not significantly declined, which resulted in a decreased ratio of Tim-3 to Tim-1 in ITP patients with active disease. During the remission stages, the levels of these transcription factors were comparable with those observed in healthy controls. The reduced levels of Tim-3/Tim-1 in PBMCs during active stages of the disease suggest a possible role in the pathogenesis and course of ITP. Regulating the balance of Tim-1 and Tim-3 in ITP patients could also be a therapeutic approach against ITP.