Related Experiment Videos
Comparison of patterns of expression of tumour necrosis factor, lymphotoxin and interleukin-6 mRNA
1Charing Cross Sunley Research Centre, Hammersmith, London.
Abstract:
The expression of the mRNA encoding tumour necrosis factor, lymphotoxin and interleukin-6 by peripheral blood mononuclear cells was analysed. Unstimulated cells contained no detectable mRNA for these cytokines, however each mRNA was transiently expressed after stimulation with either the combination of phytohaemagglutinin and phorbol ester or the single stimulus of lipopolysaccharide. The dual stimulus yielded the stronger signal. The cytokine mRNA's had short half lives, but were stabilised following protein synthesis inhibition. Cyclosporin A completely blocked induction of lymphotoxin and partially inhibited induction of TNF and IL-6 mRNA. The features of regulation described in this paper suggest these genes belong within the "early" set of genes expressed following immune cell activation.
Insights
Peripheral blood mononuclear cells express mRNA for tumour necrosis factor, lymphotoxin, and interleukin-6 upon stimulation. These cytokine mRNAs are transiently expressed and stabilized by protein synthesis inhibition.
Area of Science:
- Immunology
- Molecular Biology
Background:
- Cytokines like TNF, LT, and IL-6 are crucial in immune responses.
- Understanding the regulation of cytokine gene expression is key to immune cell activation.
Purpose of the Study:
- To analyze the mRNA expression of tumour necrosis factor (TNF), lymphotoxin (LT), and interleukin-6 (IL-6) in peripheral blood mononuclear cells.
- To investigate the regulation of these cytokine genes upon immune cell activation.
Main Methods:
- Peripheral blood mononuclear cells were stimulated with phytohaemagglutinin/phorbol ester or lipopolysaccharide.
- mRNA expression levels for TNF, LT, and IL-6 were analyzed.
- The effect of protein synthesis inhibition and Cyclosporin A on mRNA stability and induction was assessed.
Main Results:
- Unstimulated cells showed no detectable mRNA for TNF, LT, or IL-6.
- Stimulation induced transient expression of all three cytokine mRNAs, with dual stimulus yielding a stronger signal.
- Cytokine mRNAs exhibited short half-lives but were stabilized by protein synthesis inhibition.
- Cyclosporin A completely blocked LT mRNA induction and partially inhibited TNF and IL-6 mRNA induction.
Conclusions:
- The studied cytokine genes (TNF, LT, IL-6) are rapidly expressed following immune cell activation.
- Their expression is transient and tightly regulated, suggesting they belong to the 'early' gene set in immune responses.