Inhibition of NK and ADCC activity by antibodies against purified cytoplasmic granules from rat LGL tumors.

Highly purified preparations of cytoplasmic granules from transplantable rat large granular lymphocyte (LGL) tumor lines (rat natural killer (RNK) tumors) were used to immunize rabbits. Antibodies from these animals gave two precipitin lines with granule extracts in Ouchterlony experiments. They reacted with at least four different bands on nitrocellulose blots of SDS gels of LGL granule proteins.

Secretory processes in lymphocyte function.

The secretion of immunoglobulin by plasma cells has been considered a classical example of the "non-regulated" pathway of protein secretion, in which newly synthesized protein is processed by the Golgi, packaged into small vesicles, and immediately secreted without intracellular storage. In the case of lymphokine secretion by T lymphocytes, it is generally not clear whether this non-regulated pathway is also being used, as opposed to the "regulated" pathway which has been proposed to operate in the cytotoxic lymphocyte mechanism. In this case, as in mast cells and endocrine cells, proteins are synthesized and then stored in cytoplasmic granules.

Liposomes as targets for granule cytolysin from cytotoxic large granular lymphocyte tumors.

Purified cytoplasmic granules from rat large granular lymphocyte tumors having natural killer activity and/or antibody-dependent cell-mediated cytotoxicity induced a rapid, dose-dependent release of the water-soluble marker carboxyfluorescein from liposomes made of phosphatidylcholine. A solubilized, partially purified cytolytic preparation termed "cytolysin" from these granules showed identical properties. Marker release induced by granules or the cytolysin was strongly dependent on the presence of Ca2+ at a concentration of 0.