Increased Th1 and Th2 allergen-induced cytokine responses in children with atopic disease

Smart, J. M
Kemp, A. S

Department of Immunology, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Australia

Correspondence: Andrew Kemp, Department of Immunology, Royal Children's Hospital, Flemington Road, Parkville 3052, Australia. E-mail: [email protected]

Clinical & Experimental Allergy 32(5):p 796-802, May 2002.

Summary

Background

Polyclonal cytokine responses following stimulation of T cells with mitogens or superantigens provides information on cytokine production from a wide range of T cells. Alternatively allergen-induced T cell responses can provide information on cytokine production by allergen-reactive T cells. While there is evidence of increased Th2 and reduced Th1 cytokine production following T cell stimulation with non-specific mitogens and superantigens, the evidence that Th1 cytokine production to allergens is decreased in line with a postulated imbalance in Th1/Th2 responses is unclear, with studies finding decreased, no difference or increased IFN-γ responses to allergens in atopic subjects.

Objective

To examine childhood polyclonal and allergen-induced cytokine responses in parallel to evaluate cytokine imbalances in childhood atopic disease.

Methods

PBMC cytokine responses were examined in response to a polyclonal stimulus, staphylococcal superantigen (SEB), in parallel with two inhalant allergens, house dust mite (HDM) and rye grass pollen (RYE), and an ingested allergen, ovalbumin (OVA), in (a) 35 healthy children (non-atopic) and (b) 36 children with atopic disease (asthma, eczema and/or rhinitis) (atopic).

Results

Atopic children had significantly reduced IFN-γ and increased IL-4 and IL-5 but not IL13 production to SEB superantigen stimulation when compared with non-atopic children. HDM and RYE allergens stimulated significantly increased IFN-γ, IL-5 and IL-13, while OVA stimulated significantly increased IFN-γ production in atopic children.

Conclusion

We show that a polyclonal stimulus induces a reduced Th1 (IFN-γ) and increased Th2 (IL-4 and IL-5) cytokine pattern. In contrast, the allergen-induced cytokine responses in atopic children were associated with both increased Th1 (INF-γ) and Th2 (IL-5 and IL-13) cytokine production. The increased Th1 response to allergen is likely to reflect prior sensitization and indicates that increases in both Th1 and Th2 cytokine production to allergens exists concomitantly with a decreased Th1 response to a polyclonal stimulus in atopic children.