TCR ζ chain expression in T cells from patients with CML

Abstract

Chronic myeloid leukemia (CML) is a clonal disorder of the stem cells which has impaired cell-mediated immune response. Such immune dysfunction may be due to reduced expression of the T-cell receptor (TCR) ζ chain, which is an important component in TCR-mediated signal transduction. In this study, the TCR ζ expression level was detected using a real-time polymerase chain reaction with SYBR Green I technique and relative quantification method. We demonstrated that peripheral blood mononuclear cells (PBMCs) from patients with CML in chronic phase (CML-CP) and CML in complete remission (CML-CR) expressed decreased TCR ζ mRNA levels compared to healthy controls. In addition, TCR ζ chain gene expression was down-regulated in CD4⁺ T cells from patients with CML-CP. However, the mRNA expression level of the same gene in CD8⁺ T cells between CML patients and normal individuals did not differ. To confirm that this abnormal ζ chain expression could be corrected, we then stimulated the PBMCs of there patients with interleukin-2, phytohaemagglutinin and concanavalin A. The results showed that it was possible to partially up-regulate ζ chain expression. Taken together, these results indicate that TCR ζ chain expression was decreased in PBMCs and CD4⁺ T cells from patients with CML and this could be up-regulated partially by using stimulators.

Keywords:

• TCR ZETA CHAIN
• REAL-TIME PCR
• CHRONIC MYELOID LEUKEMIA