title: In vivo T-cell activation by staphylococcal enterotoxin B prevents outgrowth of a malignant tumor.
abstract: Treatment of T cells with staphylococcal enterotoxins in vitro is known to activate T cells in a subset restricted manner based on beta-chain variable region (V beta) gene expression. In particular, staphylococcal enterotoxin B (SEB) activates T cells bearing V beta 7 or V beta 8. We examined the ability of SEB to activate T cells in vivo. Treatment of C3H mice with doses of SEB ranging from 5 to 250 micrograms resulted in a dose-dependent activation of V beta 8+ T cells as reflected by increased interleukin 2 receptor (IL-2R) expression, proliferation to exogenous IL-2 and allogeneic cells, and production of gamma interferon. SEB also caused proliferation of the CD8+ subset of V beta 8+ cells in vivo. Thus, T-cell activation by SEB in vivo appears to be specific since V beta 2+ cells (non-SEB reactive) did not show increases in IL-2R expression similar to those seen with V beta 8+ cells nor did they proliferate. We then studied the ability of these activated cells to potentiate the immune response to a malignant progressor tumor. Treatment of C3H mice with 50 micrograms of SEB at the time of inoculation with tumor fragments resulted in a statistically significant decrease in the frequency of tumor outgrowth. These data demonstrate that treatment of C3H mice with SEB results in specific activation of V beta 8+ cells in vivo and that these activated cells are capable of preventing the outgrowth of a malignant tumor.
authors.affiliation: Department of Surgery, Ben May Institute, Chicago, IL.
authors.forename: K A
authors.initials: KA
authors.lastname: Newell
authors.forename: J D
authors.initials: JD
authors.lastname: Ellenhorn
authors.forename: D S
authors.initials: DS
authors.lastname: Bruce
authors.forename: J A
authors.initials: JA
authors.lastname: Bluestone
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis / Q000235:genetics; D016827:CD8 Antigens; D004768:Enterotoxins / Q000627:therapeutic use*; D005803:Genes, Immunoglobulin; D007135:Immunoglobulin Variable Region / Q000235:genetics; D007167:Immunotherapy; D008213:Lymphocyte Activation / Q000187:drug effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D009381:Neoplasms, Radiation-Induced / Q000517:prevention & control*; D015375:Receptors, Interleukin-2 / Q000032:analysis / Q000235:genetics; D012878:Skin Neoplasms / Q000517:prevention & control*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014466:Ultraviolet Rays
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D004768:Enterotoxins; D007135:Immunoglobulin Variable Region; D015375:Receptors, Interleukin-2; C031818:enterotoxin B, staphylococcal