Age-dependent variations in the expression of PLC isoforms upon mitogenic stimulation of peripheral blood T cells from healthy donors

The activation of phosphoinositide-specific phospholipase C (PLC) is one of the early responses to various growth factors and it is known that these functions are altered with ageing, In the present investigation, the expression and cellular distribution of PLC isoenzymes in immunocompetent T lymphocytes from a test group of healthy individuals over 65 years old and a comparison group of healthy donors below 30 years old were compared using Western blot and confocal microscopy. All lymphocyte samples responded biochemically to phytohaemagglutinin (PHA) stimulation, as shown by at least 10-fold increases in the beta (3) isoform and nuclear translocation of the beta (1), beta (2), beta (3), beta (4), gamma (1) and gamma (2) isoforms; however, consistent differences in the expression of the beta (2) isoform in unstimulated T cells and of the beta (2) and gamma (2) isoforms in stimulated T cells suggest that altered functions of the PLC pathway may have an age-dependent impact on signal transduction events.