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Updated: Aug 18, 2026
Identification of Mediators of T-cell Receptor Signaling via the Screening of Chemical Inhibitor Libraries
Published on: January 22, 2019
Effect of 5-azacytidine and procainamide on CD3-zeta chain expression in Jurkat T cells
Radosław Januchowski1, Paweł P Jagodzinski
1University of Medical Sciences, Department of Biochemistry and Molecular Biology, Poznań, Poland.
Abstract:
It has been observed that decrease of DNA methyltransferase 1 (DNMT1) activity is associated with low content of the CD3-zeta (zeta) chain in T cell receptor (TCR)/CD3 complex of T cells in systemic lupus erythematosus (SLE) patients. The CD3-zeta chain plays a pivotal role in intracellular signal transmission between TCR/CD3 complex and nuclei. The compounds 5'-azacytidine (AZC) and procainamide (PCA) belong to inhibitors of DNMT1, whose low activity correlates with increase in transcription of various genes. Using the reverse-transcription and real-time quantitative PCR (RQ-PCR) analysis, we indicated that AZC and PCA did not profoundly affect on CD3-zeta chain transcription in Jurkat T leukemia cells clone E6-1. However, the flowcytometric analysis revealed that AZC and PCA decreased intracellular contents of CD3-zeta chain in these cells in dose dependent manner. Our results suggest that decrease of DNMT1 activity may alter intracellular signal transmission without effect on transcription level of CD3-zeta chain.
Insights
Decreased DNA methyltransferase 1 (DNMT1) activity lowers CD3-zeta chain levels in T cells, impacting signal transmission. Inhibitors like 5'-azacytidine and procainamide reduced CD3-zeta protein without affecting its gene transcription.
Area of Science:
- Immunology
- Molecular Biology
- Epigenetics
Background:
- Decreased DNA methyltransferase 1 (DNMT1) activity is linked to lower CD3-zeta chain expression in T cells of systemic lupus erythematosus (SLE) patients.
- The CD3-zeta chain is crucial for signal transduction within the T cell receptor (TCR)/CD3 complex.
- DNMT1 inhibitors, such as 5'-azacytidine (AZC) and procainamide (PCA), are known to increase gene transcription.
Purpose of the Study:
- To investigate the effect of DNMT1 inhibition on CD3-zeta chain expression and transcription in T cells.
- To explore the relationship between DNMT1 activity, CD3-zeta chain levels, and intracellular signaling.
Main Methods:
- Utilized reverse-transcription and real-time quantitative PCR (RQ-PCR) to assess CD3-zeta chain transcription.
- Employed flow cytometry to quantify intracellular CD3-zeta chain content.
- Tested Jurkat T leukemia cells clone E6-1 with varying concentrations of AZC and PCA.
Main Results:
- AZC and PCA did not significantly alter CD3-zeta chain gene transcription in Jurkat T cells.
- Flow cytometry analysis demonstrated a dose-dependent decrease in intracellular CD3-zeta chain levels following AZC and PCA treatment.
- These findings suggest a post-transcriptional regulatory mechanism affected by DNMT1 inhibition.
Conclusions:
- DNMT1 inhibition by AZC and PCA reduces intracellular CD3-zeta chain content in T cells.
- The decrease in CD3-zeta chain occurs independently of changes in its transcriptional level.
- Reduced DNMT1 activity may modulate T cell signaling pathways through post-transcriptional mechanisms affecting CD3-zeta chain stability or degradation.
