Application of Staphylococcal Enterotoxin B on Normal and Atopic Skin Induces Up-regulation of T Cells by a Superantigen-mediated Mechanism

Background: The skin of patients with inflammatory skin diseases such as atopic dermatitis is frequently colonized with Staphylococcus aureus. Colonization with S aureus has been reported to exacerbate atopic dermatitis. Recent studies have demonstrated that S aureus isolated from the skin of patients with atopic dermatitis releases bacterial toxins that act as superantigens. We have previously applied the staphylococcal superantigen staphylococcal enterotoxin B (SEB) on intact human skin and found that the application led to induction of dermatitis.

Objective: The purpose of the study was to determine whether superantigen-induced dermatitis is primarily due to a T cell-superantigen-mediated reaction or represents nonspecific cytokine-driven inflammation.

Methods: We applied SEB, vehicle, and sodium lauryl sulfate on normal skin in healthy (n = 6) and atopic subjects (n = 6) and biopsy specimens were taken from all treated areas. The biopsy specimens from all subjects and peripheral blood from the atopic subjects were analyzed for the T-cell receptor (TCR) Vbeta repertoire with mAbs against TCR Vbeta 2, 3, 8.1, 12, 14, and 17.

Results: From all subjects, both healthy and patients with atopic dermatitis, skin biopsy specimens from SEB-treated areas demonstrated selective accumulation of T cells expressing SEB-reactive TCR Vbeta 12 and 17 (P <.05). This selective up-regulation was not found in the sodium lauryl sulfate-treated areas.

Conclusion: Our data strongly support that superantigen-induced T-cell activation is involved in the dermatitis seen after experimental application of SEB on intact skin.