ABSTRACT
Objective: To study the expression and activity changes of methionine adenosyltransferase (MAT) in human peripheral T lymphocytes. Methods: The expression of MAT mRNA was detected by RT-PCR and the activity of MAT was measured. Results: After stimulated by IL-2, PHA and anti-CD3 antibody, MAT-Ⅱ gene expression increased by (8.9? 2.1), (7.7?1.9) and (8.0?1.8) times, respectively, and the expression peak was at 8, 4 and 8 h,respectively; MAT activity continuously increased in 48 h. S-adenosylmethioinie (SAM) moderately induced IL-2 and IFN secretion by human T cells. SAM(0.1 mg/ml) downregulated the expression and activity of MAT-Ⅱ and the secretion of IL-2 and IFN induced by PHA or anti-CD3 antibody in human T cells. Conclusion:MAT is involved in the activation of T lymphocytes, and high dose of SAM may also inhibit its activation through PHA and anti-CD3 antibody.