Blimp-۱ Expression as an Exhaustion Transcription Factor in Chronic Lymphocytic Leukemia

Background: PPreviously, it was shown that exhausted CD۴+ and CD۸+ T cells in chronic lymphocytic leukemia (CLL) co-express the two immune-inhibitory receptors, Tim-۳ and PD-۱. Present study investigated the expression of Blimp-۱, a transcription factor involved in T cell exhaustion, in patients with CLL. Materials and Methods: Peripheral blood mononuclear cells were collected from ۲۵ untreated CLL patients and ۱۵ sex- and age-matched normal subjects. CLL patients were clinically classified according to the Rai staging system. The relative expression of Blimp-۱ mRNA was determined by quantitative Real Time Polymerase Chain Reaction (qRT-PCR) after normalization with β-actin. Results: Expression of Blimp-۱ mRNA was much higher in CLL patients than in normal controls (p=۰.۰۰۱). Moreover, Blimp-۱ was more expressed in patients with advanced clinical stages of CLL compared to those with early stages of the disease (p=۰.۰۱). Interestingly, the Blimp-۱ expression was correlated with the frequencies of exhausted Tim-۳+/PD-۱+/CD۴+ and Tim-۳+/PD-۱+/CD۸+ T cells in CLL patients. Conclusion: Our results highlight the role of Blimp-۱ transcription factor in T cell exhaustion of CLL.

Keywords:

Exhausted T cell , Blimp-۱ , Chronic Lymphocytic Leukemia