Background The T cell reactivity to the major allergen of bee venom, phospholipase A2, has been thoroughly characterized. In contrast, only little is known about the human cellular response to major allergens from wasp venom.
Objective To characterize the human T cell response to antigen 5 from Vespula vulgaris, Ves v 5.
Methods Recombinant Ves v 5 was used to establish allergen-specific T cell lines (TCL) and T cell clones (TCC) from the peripheral blood of vespid-allergic and non-allergic individuals. Ves v 5-specific TCL were mapped for T cell epitopes using overlapping synthetic peptides representing the complete amino acid sequence of Ves v 5. Ves v 5-specific TCC were analysed for antigen-induced secretion of IL-4, IFN-γ and IL-10.
Results Seventeen distinct T cell epitopes were recognized by allergic individuals among which Ves v 5181–192 was identified as a dominant T cell epitope. Partially different epitopes were observed in TCL from non-allergic subjects and the dominant epitope Ves v 5181–192 was not prevalent in these cultures. Ves v 5-specific TCC isolated from allergic individuals did not show the typical T helper type 2 (Th2)-like cytokine profile in response to specific stimulation, i.e. high amounts of IL-4 and low IFN-γ. TCC from non-allergic individuals showed a Th1-like cytokine pattern.
Conclusions Our findings provide evidence that the allergic T cell response to Ves v 5 is not Th2-dominated and that different immunogenic sites on this major wasp venom allergen are recognized by allergic and non-allergic individuals.