LARGE GRANULAR LYMPHOCYTES IN HUMAN PERIPHERAL-BLOOD - ULTRASTRUCTURAL AND CYTOCHEMICAL CHARACTERIZATION OF THE GRANULES

  • 1 January 1982
    • journal article
    • research article
    • Vol. 59  (2) , 277-283
Abstract
Large granular lymphocytes (LGL) are defined as nonadherent mononuclear cells with cytoplasmic azurophilic granules, avid receptors for the Fc portion of IgG, and cytotoxic functions (NK or ADCC activities). The granules of LGL isolated from human peripheral blood were analyzed by enzyme cytochemistry and EM. In the single cells, granules at different stages of maturation could be detected; in addition, packaging of the granules took place in the proximity of the Golgi apparatus, which is similar to that seen in secretory cell types. Acid phosphatase (AP) was observed within the granules and the vesicles located in the Golgi area; the Golgi apparatus identified through its thiamine pyrophosphatase-positivity was consistently negative for AP. .alpha.-Naphthylacetate esterase (ANAE) activity was localized in the granules as well as on the membrane of LGL and monocytes. The ANAE activity of LGL was of the monocytic and not of the lymphocytic type, as shown by NaF inhibition. The LGL granules, although identifiable as primary lysosomes, were not involved in the process of phagocytosis, since LGL failed consistently to ingest latex particles or opsonized red cells.