title: Stimulation of helper/delayed-type hypersensitivity T cells by flavivirus infection: determination by macrophage procoagulant assay.
abstract: West Nile virus (WNV)-immune spleen cells produced an inducer of macrophage procoagulant activity (MPCA) on restimulation with WNV in vitro. This response was specific for WNV and depended on the presence of Thy 1+, L3T4+ and also Ia+ cells but not Lyt 2+ cells. It could be induced by culture with large amounts of non-infectious, u.v.-irradiated virus or with high doses of infectious virus. Inoculation of mice with low titres of infectious, but not with u.v.-irradiated, virus primed for this in vitro response. The time of maximum production of procoagulant-inducing factor was also the period of greatest [3H]thymidine uptake and release of interleukin-2 (IL-2)-like activity. In bulk cultures, MPCA-inducing factor was more readily quantified than IL-2. T cells of the helper/delayed-type hypersensitivity class are thus stimulated by WNV and this aspect of cell-mediated immunity can be readily assayed in vitro.
mesh_terms: D000818:Animals; D001779:Blood Coagulation Factors / Q000032:analysis*; D002460:Cell Line; D002522:Chlorocebus aethiops; D006968:Hypersensitivity, Delayed; D007668:Kidney; D008213:Lymphocyte Activation; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008808:Mice, Inbred CBA; D008815:Mice, Inbred Strains; D012672:Semliki forest virus / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014036:Togaviridae Infections / Q000276:immunology*; D014902:West Nile virus / Q000276:immunology
chemical_list: D001779:Blood Coagulation Factors; C045072:macrophage procoagulant activity