CD4 T-Cell Cytokine Response to Mite Recombinant Tropomyosin in Mite, Snail and Shrimp Allergic Patients

Allergies to snails and mites are definitely linked. Snail allergens have been already identified and there is no evidence of crossreaction between snail and mite tropomyosin. This work is a preliminary study on immune cell function, evaluating possible tropomyosin-triggering in a snail-mite-shrimp cross-reaction. Peripheral blood mononuclear cells from 6 different phenotype patients in relation to snails, mites and crustaceans, were cultured with mite recombinant tropomyosin (rDer p 10), anti-CD28 and brefeldin A. Phytohemagglutinin mitogen was used as a positive control. CD4 T-cell response was evaluated towards CD69, IFN-γ, IL-2, IL-4, IL-5 and IL-13, in flow cytometry. rDer p 10 induced different cytokine expression in the six phenotypes. Allergen-specific IFN-γ stimulation was suggested by an increase in IFN-γ, IL-5, and IL-13 only in allergic to crustaceans, with a dose-dependent effect on IL-5 and IL-13. Tropomyosin is probably the main allergen responsible for the mite-shrimp crossreactivity but may not play a major role in snail-mite-shrimp cross-reactions. This work was done in the Laboratory of Immunology from Hospital de S. Bernardo, Setubal, Portugal.