TSST-1-specific changes in peripheral T cell function are not observed in BP patients colonized with TSST-1+ staphylococcus aureus.

Summary: Abstract Body: Bullous pemphigoid (BP) is an autoimmune skin blistering disease that primarily affects the elderly over the age of 65. Studies have found that cutaneous microbiota profiles in patients in autoimmune bullous diseases differ from that of healthy individuals. Most (~90%) BP patients are colonized with Staphylococcus aureus (S. aureus) that produces toxic shock syndrome toxin-1 (TSST-1), a known T cell superantigen that binds T cell receptor (TCR) Vβ2 chain. However, it is not known if S. aureus colonization contributes to immune dysfunction in BP. We evaluated peripheral homeostasis through examination of TCR Vβ repertoire utilization of BP patients and controls. Surprisingly, there was no expansion of Vβ2 in BP patients when both expression of 24 TCR Vβ genes was evaluated in purified CD4+ T cells by RT-qPCR and cell surface expression measured by flow cytometry. However, significant decreases in Vβ7, 13c, and 17 in BP patients were observed by RT-qPCR (p<0.05), and increases in Vβ5.2 and 5.3 expression were observed by flow cytometry (p<0.05). To assess T cell function, the proliferative response of CD4+T cells to staphylococcal toxins (TSST-1, staphylococcal enterotoxin G, staphylococcal enterotoxin-like I) was examined in vitro. As above, no significant differences were seen between BP patients and controls. These findings suggest that peripheral T cells in BP patients may not be influenced by immunoregulatory events that are TSST-1+ specific, and that peripheral immune status may not reflect what is happening in the skin. Tian (Tracy) Y. Chen¹, Tyler P. Crowe¹, Maryam Fakhimi¹, Janet A. Fairley¹, Patrick Schlievert², Kelly N. Messingham¹ 1. Dermatology, University of Iowa Hospitals and Clinics, Iowa City, IA, United States. 2. Microbiology and Immunology, University of Iowa Hospitals and Clinics, Iowa City, IA, United States. Adaptive and Auto-Immunity