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SECRETORY PRODUCTS FROM THROMBIN‐STIMULATED HUMAN PLATELETS EXERT AN INHIBITORY EFFECT ON NK‐CYTOTOXIC ACTIVITY
Author(s) -
Madsen P. SKOV,
Hokland P.,
Hokland M.
Publication year - 1986
Publication title -
acta pathologica microbiologica scandinavica series c: immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0108-0202
DOI - 10.1111/j.1699-0463.1986.tb02111.x
Subject(s) - platelet , k562 cells , cytotoxic t cell , thrombin , in vitro , cytotoxicity , secretion , inhibitory postsynaptic potential , chemistry , microbiology and biotechnology , biology , immunology , biochemistry , endocrinology
We have investigated the interaction between human platelets and the NK‐system, with special emphasis on the action of secretory products from platelets in an NK assay with 51 Cr‐labelled K562 as target cells. Supernatants from thrombin‐stimulated platelets added to the NK assay consistently decreased the NK‐cytotoxicity by 40% 4.3%, indicating the existence of secreted products from platelets as a source of NK‐inhibiting substances. In contrast, no direct cytotoxic effect of these secretory products on the target cells (K562) was seen. Thus, normal human platelets, when stimulated with thrombin, are capable of secreting different, yet undefined factors, which significantly inhibit NK activity in vitro. The results also suggest that the role of products from contaminating in vitro activated platelets should be borne in mind when performing conventional NK assays.