PROTEIN-KINASE-C ISOFORM EXPRESSION IN CD45RA(-LYMPHOCYTES() AND CD45RO(+) T)

Differences in levels of specific enzymes utilized in intracellular si gnalling could be a factor in the distinct signalling properties obser ved in memory and naive T cells. We have studied the expression of bot h classical and non-classical protein kinase of C (PKC) isoenzymes in CD45RA and CD45RO cells using a combination of Western blot and flow c ytometric analysis. These data indicate that CD45RA cells express high er levels of PKC alpha, PKC beta and PKC delta than CD45RO cells. In a ddition, CD45RA(+) cells show greater proliferative activity when stim ulated with phorbol myristate acetate (PMA) and calcium ionophore than their CD45RO(+) counterparts. Variations in the levels of these isoen zymes could be implicated in functional differences, such as prolifera tion and cytokine production, in these cell subsets.