Histochemical patterns of human T lymphocyte subpopulations with nonspecific esterase staining

Alpha-naphthyl-acetate-esterase (ANAE) activity was histochemically demonstrated in human T lymphocytes and their subpopulations. Examination of T lymphocytes bearing Fc receptors for IgM showed the presence of circumscribed deposits of esterase activity, while T cells with FC receptors for IgG showed of predominantly diffuse granular pattern. The difference in the topography of the enzymatic activity was shown to be related to cellular activation resulting from exposure to IgG-sensitized bovine erythrocytes or to strong polyclonal activation by lectin mitogens. The ANAE stain also characterized monocytes, which exhibited an intense nongranular cytoplasmic stain. Non-T cells showed no detectable ANAE activity when tested by this method.