Evaluation of gene expression in human lymphocytes activated in the presence of melatonin.

The effect of melatonin on the expression of genes previously correlated to T lymphocyte activation (HLA-DRB, thymosin beta 10 (beta-Tim)) and to Lymphokine Activated Killer (LAK) activity (beta-Tim, Tumour Rejection Antigen (TRA 1), nRap 2) was investigated in phytohemagglutinin (PHA)-stimulated human lymphocyte cultures. The aim was to find an enhancing effect of this substance on anti-tumoral immune defences as suggested by studies on tumour progression in mice and clinical immunotherapy trials in humans. mRNA obtained from melatonin-treated and -untreated PHA-stimulated lymphocytes was retrotranscribed and amplified by RT-PCR using primers based on the sequences of the selected genes.