Cytokine responses to Der p 1 and Der p 7: house dust mite allergens with different IgE-binding activities

Background There is very limited information comparing T‐cell responses to different house dust mite (HDM) allergens even though T cells are essential in the initiation and regulation of immunoglobulin (Ig) E synthesis and eosinophilia. Objective To compare the level of T‐cell proliferation and cytokine production to the group 1 and group 7 HDM allergens which are known to have different IgE‐binding capabilities. Methods Freshly isolated peripheral blood mononuclear cells (PBMC) from HDM‐allergic and HDM‐nonallergic donors were stimulated with the group 1 and group 7 allergens of Dermatophagoides pteronyssinus and the level of proliferation as well as IL‐5 and IFNγ production were measured. Results The proliferative and IL‐5 production to the group 1 and group 7 allergens were equivalent despite the group 7 allergen's lower frequency of IgE‐binding. However more IFNγ was produced to Der p 7 than to Der p 1, particularly for the nonallergic donors. As expected IL‐5 production was much higher for PBMC from the allergic donors than for cells from nonallergics; however, there was no difference in the level of T‐cell proliferation between the donor groups. Conclusion The relative importance of the individual HDM allergens is normally determined by measuring the frequency of IgE‐binding to the allergen in sera from an allergic population. The equivalent increased IL‐5 response of PBMC from allergic people to the group 1 and group 7 allergens despite the different IgE‐inducing activity indicates that these allergens may be equally capable of contributing to an asthmatic response by inducing eosinophilia.