title: Primary cytotoxicity of SEB-activated human PBMC and separated CD8+ and CD4+ T lymphocytes elicited by two different stimulation protocols.
abstract: The primary cytotoxicity of Staphylococcal enterotoxin B (SEB)-stimulated PBMC and separated CD8+ and CD4+ T cells against Burkitt's lymphoma target cells has been characterized by applying two stimulation protocols. In the bulk protocol, the PBMC were stimulated with 100 ng/mL SEB for 3 days before separation to CD4+ and CD8+ T subsets. In the direct protocol, the separated CD4+ and CD8+ T cells were stimulated with 100 ng SEB preabsorbed to mitomycin C (MMC)-treated APC. Comparison of the results of the two different protocols revealed the following differences: (i) PBMC in the direct protocol provided greater cytolytic activity than in the bulk protocol; and (ii) the CD4+ T cells acquired cytotoxicity only in the direct protocol. Unexpectedly, the superantigen-dependent cellular cytotoxicity (SDCC) of SEB-stimulated cells was not dominant compared with the basal cytotoxicity. The classical NK target, K-562 was also sensitive to SEB-augmented cytotoxicity. The parallel stimulation with IL-2 and SEB caused a similar extent of cytotoxicity enhancement against both types of target cells. However, the cyclosporin A (CSA) inhibited only the SEB-induced cytotoxicity. The results suggest that SEB-induced PBMC acquire mainly a LAK-like cytotoxicity, as a consequence of newly produced lymphokines. This observation might propose a different approach in pathological studies.
authors.affiliation: National Medical Children's Medical Research Center, Tokyo, Japan.
authors.forename: G
authors.initials: G
authors.lastname: Seprényi
authors.forename: J
authors.initials: J
authors.lastname: Abe
authors.forename: T
authors.initials: T
authors.lastname: Kohsaka
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002469:Cell Separation; D003602:Cytotoxicity, Immunologic; D004768:Enterotoxins / Q000008:administration & dosage* / Q000276:immunology*; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008213:Lymphocyte Activation; D013211:Staphylococcus aureus / Q000276:immunology; D018089:Superantigens / Q000032:analysis / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D004768:Enterotoxins; D007376:Interleukin-2; D018089:Superantigens; C031818:enterotoxin B, staphylococcal