Shift from Th2 to Th1 response in immunotherapy with venoms

Cytokines released from T lymphocytes regulate antibody production by B lym phocytes and releasability of mast cells and basophils. Immune tolerance in specific allergen (Ag) immunotherapy (SIT) might be a consequence of decre ased Th2 or increased Th1 response of Ag specific T lymphocytes. We compare d function of T lymphocytes in 11 patients with Hymenoptera venom allergy a nd in 7 healthy volunteers. We followed function of T lymphocytes in 6 pati ents during SIT. We measured released IL-2, IFN-gamma, IL-4 and IL-5 from A g and mitogens (either with phorbol-miristate-acetate (PMA) and ionomycine or anti-CD3 antibodies) stimulated peripheral blood mononuclear cells (PBMC ). After stimulation with Ag PBMC of patients released 86 +/- 133 pg/ml IFN -gamma and 19.7 +/- 20.1 pg/ml IL-4 (Th2 response), PBMCs of healthy contro ls released 184 +/- 116 pg/ml IFN-gamma and 4.8 +/- 8 pg/ml IL-4 (Th1 respo nse). Spontaneous release of IFN-gamma in cultures of PBMC of patients incr eased after rush SIT (before: 25 +/- 31 pg/ml, after 241 +/- 281 pg/ml, p<0 .05). After 6 months of SIT response of PBMCs of patients became similar to response of PBMCs of healthy controls. Time pattern of cytokines secreted from PBMCs after stimulation with PMA and ionomycine was different than aft er stimulation through T-cell receptor/CD3 complex.