In vitro induction of human helper T cell activity by Trypanosoma brucei.
Proliferation of peripheral blood T lymphocytes from unsensitized donors in response to fractions of Trypanosoma brucei was observed to be monocyte-dependent. The activated T cells displayed enhanced 'helper' activity, but no 'suppressor' activity during pokeweed mitogen (PWM)-induced immunoglobulin (IgM and IgG) synthesis, and were resistant to the inhibitory effects of theophylline on E rosette formation. Whilst in vivo studies have failed to reveal excessive T cell proliferation in patients with sleeping sickness, these results suggest a possible role for T cells in the induction of hypergammaglobulinaemia characteristic of this disease. Trypanosome fractions were not inhibitory to PWM-induced proliferation, and actually enhanced immunoglobulin synthesis. Thus it is unlikely that direct inhibition by the parasite per se is a major factor in the generation of immunosuppression by the T. brucei subgroup.
D001402:B-Lymphocytes / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007165:Immunosuppression Therapy; D008213:Lymphocyte Activation; D008297:Male; D009000:Monocytes / Q000276:immunology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects / Q000276:immunology*; D013806:Theophylline / Q000494:pharmacology; D014346:Trypanosoma brucei brucei / Q000276:immunology*
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011043:Pokeweed Mitogens; D013806:Theophylline