Selective restimulation of antigen or allergen preactivated T cells using OKT3 F(ab)2 results in the secretion of TH-1 or TH-2-like cytokine patterns

Summary Background The synthesis of IgE is regulated by cytokines secreted from T‐helper cells. The studies on cytokine secretion by peripheral blood mononuclear cells (PBMC) upon stimulation with antigen or allergen are ditficult due to low levels of cytokines, especially of inlerieukin‐4 (IL‐4). Objective ln this study we tried lo establish a culture system, which could enable the measurement of the cytokine profiles in specifically activated cultures. Methods Three methods to potentiate cytokine secretion were evaluated: PBMC from bee venom or house dust mite (Dermatophagoides pteronyssinus) allergic patients as well as normal subjects were stimulated either with the major bee venom allergen phosphoiipase A2 (PLA) or with the major D. pteronyssinus allergen (Der p 1) or with the control antigens tetanus toxoid (TT) and purified protein derivate (PPD). After 7 days of culture the cells were restimulated either wilh pkistie bound 0KT3 F(ab)2 monoclonal antibodies (MoAbs), with the appropriate antigen + antigen presenting cells or with IL‐2. The secretion of cylokines (IL‐4, IFNγ) was measured after restimulation of the cultures (day 8). Results While OKT3 F(ab)2 was unable lo activate resting T cells, it could restimulate preactivaled cells. Restimulalion with OKT3 F(ab)2 induced higher IL‐4 and IFN7 secretion than restimulation with IL‐2 or antigen. TT and PLA stimulated a similar cytokine secretion prolile in normal and PLA allergic subjects with substantial levels of both lL‐4 and IFNγ. In contrast, PPD induced virtually only IFNγ secretion. Der p 1 stimulated mainly IL‐4 seerclion but also IFNγ production in some mite allergic palienis. Conclusion We have established a cell culture system, which combines antigen specificity with a strong cytokine inducing signial provided by anti‐CD3 MoAbs. TH‐1 and TH‐2 characteristic cytokine patterns can be observed in short‐term PBMC cultures already after 8 days of culture.