Increased expression of α4β7 integrin on food allergen-stimulated CD4⁺ T cells in active food allergic enterocolitis

Abstract

We used flow cytometry to investigate the expression of α4β7 integrin on peripheral blood CD4⁺ T cells stimulated with αs-casein, one of the major allergens in milk allergy, in patients with milk-induced enterocolitis. In the active state of the disease, the levels of α4β7 integrin on αs-casein-stimulated CD4⁺ T cells, as well as the numbers of positive cells, were higher than in the age-matched control. Upon outgrowing milk allergy, α4β7 integrin levels decreased to the same levels as in the healthy control. The proliferative responses of peripheral blood mononuclear cells to αs-casein in the active state did not differ from those in the outgrown state, suggesting that the expression of α4β7 integrin on milk allergen-activated T cells is a marker of the activation state leading to the pathogenesis of milk-allergic enterocolitis.