Staphylococcal α-Toxin Induces a Higher T Cell Proliferation and Interleukin-31 in Atopic Dermatitis

Background: Patients with atopic dermatitis (AD) are frequently colonized with α-toxin-producing Staphylococcus aureus which is in turn positively correlated with the severity of eczema. Methods: In this study we addressed T cell proliferation and T cell as well as monocyte cytokine secretion upon α-toxin stimulation in peripheral blood mononuclear cells (PBMCs) from AD patients compared to healthy controls. Results: We found that α-toxin stimulation of PBMCs markedly enhanced T cell proliferation both in patients with AD and healthy controls and was significantly increased in AD patients compared to healthy controls. PBMCs of AD patients secreted significantly more IL-31 compared to those of healthy controls upon α-toxin and SEB stimulation. Moreover, α-toxin stimulation yielded an increase in T cell (IL-2, IL-9, IL-10 and IFN-γ) as well as monocyte (IL-1β and TNF-α) cytokine secretion. Conclusion: Our results could partly explain how skin colonization and infection with S. aureus can contribute to chronic skin inflammation and pruritus in AD.