Distribution of acid alpha-naphthyl acetate esterase among human T lymphocyte subsets.

Human T lymphocyte subsets, identified by means of OKT3, 4 and 8 monoclonal antibodies, were isolated by a fluorescence activated cell sorter (FACS IV) and analyzed for distribution of alpha-naphthyl acetate esterase (ANAE) activity. As compared to OKT8+ lymphocytes a higher proportion of OKT4+ lymphocytes was ANAE-positive exhibiting a spot or dot-like pattern in the cytoplasm. OKT8 and 4 positive subsets showed a similar ANAE distribution in diffuse granular form. Although OKT4 and OKT8 populations presented a different ANAE dot-like reactivity, this marker did not allow as clear a distinction between them as that reported for TG and TM lymphocytes.