Secretion of two different flowing masses by lymphokine-activated killer cells.

When grown on mesenchyme-fibroblastoid monolayers made of 16-day-old embryos, lymphokine-activated killer (LAK) cells in clones derived from nude mouse lymph node cells are signaled to synthesize and secrete two mucoid masses. The first is made of chondroitin sulfate, as determined by the degradation of 35S- and [3H]glucosamine-labeled macromolecules in the extracellular matrix, by hyaluronidase, and by chondroitin sulfate lyase AC. This determination correlates with the distinctive blue staining by periodic acid-Schiff/alcian blue (PAS-Ab) at pH 1.0. In the present study, two different masses were identified when methanol-fixed and dried LAK cells and their secretions were examined prior to staining. The chondroitin-sulfate-containing mass appeared as an optically bright structure. It also produced a positive fluorescence with rabbit anti-mouse perforin. The second structure, which appeared as a flowing material or as filling holes in the first, could be identified by its high optical density. However, it was not stained by PAS-Ab and was not blackened by osmium tetroxide. The biochemical nature of the second mass has yet to be determined. Both masses seemed eventually to mix, producing pools, in lacunae, or to spread into the culture space.